diff --git a/Makefile b/Makefile
index f85dca145..98b871bb4 100644
--- a/Makefile
+++ b/Makefile
@@ -24,12 +24,16 @@ INSTALL_INFO = install-info
 # This is particularly useful when EMACS is set in ~/.bash_profile
 #
 EMACS := $(shell which "$${EMACS}" || which "emacs")
+EMACS_VERSION := $(shell "$(EMACS)" -Q --batch --eval '(princ emacs-version)')
 
 EFLAGS = --eval "(add-to-list 'load-path (expand-file-name \"tests/compat\") 'append)" \
 	 --eval "(when (< emacs-major-version 24) \
 		    (setq byte-compile-warnings '(not cl-functions)))" \
 	 --eval '(setq byte-compile-error-on-warn t)' \
-	 --eval '(when (not (version< emacs-version "24.4")) (setq load-prefer-newer t))'
+	 --eval '(when (not (version< emacs-version "24.4")) (setq load-prefer-newer t))' \
+	 --eval '(defun byte-compile-dest-file (filename) \
+                    (concat (file-name-directory filename) "build-" emacs-version "/" \
+                            (file-name-nondirectory filename) "c"))'
 
 BATCH = $(EMACS) $(EFLAGS) --batch -Q -L .
 
@@ -75,17 +79,13 @@ ELFILES = \
 	haskell-utils.el \
 	inf-haskell.el
 
-ELCFILES = $(ELFILES:.el=.elc)
+ELCHECKS := $(shell echo tests/*-tests.el)
+
 AUTOLOADS = haskell-mode-autoloads.el
 
 PKG_DIST_FILES = $(ELFILES) logo.svg NEWS haskell-mode.info dir
-ELCHECKS=$(addprefix check-, $(ELFILES:.el=))
-
-%.elc: %.el
-	@$(BATCH) \
-		 -f batch-byte-compile $*.el
 
-.PHONY: all compile info clean check $(ELCHECKS) elpa package check-emacs-version
+.PHONY: all compile info clean check check-emacs-version
 
 all: check-emacs-version compile $(AUTOLOADS) info
 
@@ -100,20 +100,30 @@ check-emacs-version :
                             (message \"   3.  make EMACS=/path/to/emacs\")			\
                             (kill-emacs 2))"
 
-compile: $(ELCFILES)
-
-$(ELCHECKS): check-%: %.el %.elc
-	@$(BATCH) --eval '(when (check-declare-file "$*.el") (error "check-declare failed"))'
-	@if [ -f "$(<:%.el=tests/%-tests.el)" ]; then \
-		$(BATCH) -l "$(<:%.el=tests/%-tests.el)" -f ert-run-tests-batch-and-exit; \
+compile: build-$(EMACS_VERSION)
+
+build-$(EMACS_VERSION) : $(ELFILES)
+	if [ ! -d $@ ]; then mkdir $@; fi
+	$(BATCH) -f batch-byte-compile-if-not-done $^
+
+check-%: tests/%-tests.el
+	$(BATCH) -l "$<" -f ert-run-tests-batch-and-exit;
+
+check: $(ELCHECKS) build-$(EMACS_VERSION)
+	$(BATCH) --eval "(when (>= emacs-major-version 24)                            \
+                           (require 'undercover)                                      \
+                           (undercover \"*.el\" (:exclude \"haskell-mode-pkg.el\")))" \
+                 $(patsubst %,-l %,$(ELCHECKS))				              \
+                 -f ert-run-tests-batch-and-exit
+	@TAB=$$(echo "\t"); \
+	if grep -Hn "[ $${TAB}]\+\$$" *.el; then \
+	    echo "Some files contain whitespace at the end of lines, correct it"; \
+	    exit 3; \
 	fi
-	@echo "--"
-
-check: $(ELCHECKS)
 	@echo "checks passed!"
 
 clean:
-	$(RM) $(ELCFILES) $(AUTOLOADS) $(AUTOLOADS:.el=.elc) haskell-mode.info dir
+	$(RM) -r build-$(EMACS_VERSION) $(AUTOLOADS) $(AUTOLOADS:.el=.elc) haskell-mode.info dir
 
 info: haskell-mode.info dir
 
@@ -158,7 +168,7 @@ doc/html : doc/html/index.html			\
 deploy-manual : doc/html
 	cd doc && ./deploy-manual.sh
 
-$(AUTOLOADS): $(ELFILES) haskell-mode.elc
+$(AUTOLOADS): $(ELFILES)
 	$(BATCH) \
 		--eval '(setq make-backup-files nil)' \
 		--eval '(setq generated-autoload-file "$(CURDIR)/$@")' \
diff --git a/README.md b/README.md
index 7c7839a43..b4264b034 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@
 
 This is an Emacs mode for editing, debugging and developing Haskell programs.
 
+[![Coverage Status](https://coveralls.io/repos/haskell/haskell-mode/badge.svg?branch=master&service=github)](https://coveralls.io/github/haskell/haskell-mode?branch=master)
 [![Build Status](https://travis-ci.org/haskell/haskell-mode.svg?branch=master)](https://travis-ci.org/haskell/haskell-mode)
 [![Melpa Status](http://melpa.org/packages/haskell-mode-badge.svg)](http://melpa.org/#/haskell-mode)
 [![Melpa Stable Status](http://stable.melpa.org/packages/haskell-mode-badge.svg)](http://stable.melpa.org/#/haskell-mode)
diff --git a/tests/compat/dash.el b/tests/compat/dash.el
new file mode 100644
index 000000000..5f9f8404b
--- /dev/null
+++ b/tests/compat/dash.el
@@ -0,0 +1,2436 @@
+;;; dash.el --- A modern list library for Emacs  -*- lexical-binding: t -*-
+
+;; Copyright (C) 2012-2015 Free Software Foundation, Inc.
+
+;; Author: Magnar Sveen <magnars@gmail.com>
+;; Version: 2.12.1
+;; Keywords: lists
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; A modern list api for Emacs.
+;;
+;; See documentation on https://github.com/magnars/dash.el#functions
+;;
+;; **Please note** The lexical binding in this file is not utilised at the
+;; moment. We will take full advantage of lexical binding in an upcoming 3.0
+;; release of Dash. In the meantime, we've added the pragma to avoid a bug that
+;; you can read more about in https://github.com/magnars/dash.el/issues/130.
+;;
+
+;;; Code:
+
+(defgroup dash ()
+  "Customize group for dash.el"
+  :group 'lisp
+  :prefix "dash-")
+
+(defun dash--enable-fontlock (symbol value)
+  (when value
+    (dash-enable-font-lock))
+  (set-default symbol value))
+
+(defcustom dash-enable-fontlock nil
+  "If non-nil, enable fontification of dash functions, macros and
+special values."
+  :type 'boolean
+  :set 'dash--enable-fontlock
+  :group 'dash)
+
+(defmacro !cons (car cdr)
+  "Destructive: Set CDR to the cons of CAR and CDR."
+  `(setq ,cdr (cons ,car ,cdr)))
+
+(defmacro !cdr (list)
+  "Destructive: Set LIST to the cdr of LIST."
+  `(setq ,list (cdr ,list)))
+
+(defmacro --each (list &rest body)
+  "Anaphoric form of `-each'."
+  (declare (debug (form body))
+           (indent 1))
+  (let ((l (make-symbol "list")))
+    `(let ((,l ,list)
+           (it-index 0))
+       (while ,l
+         (let ((it (car ,l)))
+           ,@body)
+         (setq it-index (1+ it-index))
+         (!cdr ,l)))))
+
+(defun -each (list fn)
+  "Call FN with every item in LIST. Return nil, used for side-effects only."
+  (--each list (funcall fn it)))
+
+(put '-each 'lisp-indent-function 1)
+
+(defmacro --each-while (list pred &rest body)
+  "Anaphoric form of `-each-while'."
+  (declare (debug (form form body))
+           (indent 2))
+  (let ((l (make-symbol "list"))
+        (c (make-symbol "continue")))
+    `(let ((,l ,list)
+           (,c t)
+           (it-index 0))
+       (while (and ,l ,c)
+         (let ((it (car ,l)))
+           (if (not ,pred) (setq ,c nil) ,@body))
+         (setq it-index (1+ it-index))
+         (!cdr ,l)))))
+
+(defun -each-while (list pred fn)
+  "Call FN with every item in LIST while (PRED item) is non-nil.
+Return nil, used for side-effects only."
+  (--each-while list (funcall pred it) (funcall fn it)))
+
+(put '-each-while 'lisp-indent-function 2)
+
+(defmacro --dotimes (num &rest body)
+  "Repeatedly executes BODY (presumably for side-effects) with `it` bound to integers from 0 through NUM-1."
+  (declare (debug (form body))
+           (indent 1))
+  (let ((n (make-symbol "num")))
+    `(let ((,n ,num)
+           (it 0))
+       (while (< it ,n)
+         ,@body
+         (setq it (1+ it))))))
+
+(defun -dotimes (num fn)
+  "Repeatedly calls FN (presumably for side-effects) passing in integers from 0 through NUM-1."
+  (--dotimes num (funcall fn it)))
+
+(put '-dotimes 'lisp-indent-function 1)
+
+(defun -map (fn list)
+  "Return a new list consisting of the result of applying FN to the items in LIST."
+  (mapcar fn list))
+
+(defmacro --map (form list)
+  "Anaphoric form of `-map'."
+  (declare (debug (form form)))
+  `(mapcar (lambda (it) ,form) ,list))
+
+(defmacro --reduce-from (form initial-value list)
+  "Anaphoric form of `-reduce-from'."
+  (declare (debug (form form form)))
+  `(let ((acc ,initial-value))
+     (--each ,list (setq acc ,form))
+     acc))
+
+(defun -reduce-from (fn initial-value list)
+  "Return the result of applying FN to INITIAL-VALUE and the
+first item in LIST, then applying FN to that result and the 2nd
+item, etc. If LIST contains no items, return INITIAL-VALUE and
+FN is not called.
+
+In the anaphoric form `--reduce-from', the accumulated value is
+exposed as `acc`.
+
+See also: `-reduce', `-reduce-r'"
+  (--reduce-from (funcall fn acc it) initial-value list))
+
+(defmacro --reduce (form list)
+  "Anaphoric form of `-reduce'."
+  (declare (debug (form form)))
+  (let ((lv (make-symbol "list-value")))
+    `(let ((,lv ,list))
+       (if ,lv
+           (--reduce-from ,form (car ,lv) (cdr ,lv))
+         (let (acc it) ,form)))))
+
+(defun -reduce (fn list)
+  "Return the result of applying FN to the first 2 items in LIST,
+then applying FN to that result and the 3rd item, etc. If LIST
+contains no items, FN must accept no arguments as well, and
+reduce return the result of calling FN with no arguments. If
+LIST has only 1 item, it is returned and FN is not called.
+
+In the anaphoric form `--reduce', the accumulated value is
+exposed as `acc`.
+
+See also: `-reduce-from', `-reduce-r'"
+  (if list
+      (-reduce-from fn (car list) (cdr list))
+    (funcall fn)))
+
+(defun -reduce-r-from (fn initial-value list)
+  "Replace conses with FN, nil with INITIAL-VALUE and evaluate
+the resulting expression. If LIST is empty, INITIAL-VALUE is
+returned and FN is not called.
+
+Note: this function works the same as `-reduce-from' but the
+operation associates from right instead of from left.
+
+See also: `-reduce-r', `-reduce'"
+  (if (not list) initial-value
+    (funcall fn (car list) (-reduce-r-from fn initial-value (cdr list)))))
+
+(defmacro --reduce-r-from (form initial-value list)
+  "Anaphoric version of `-reduce-r-from'."
+  (declare (debug (form form form)))
+  `(-reduce-r-from (lambda (&optional it acc) ,form) ,initial-value ,list))
+
+(defun -reduce-r (fn list)
+  "Replace conses with FN and evaluate the resulting expression.
+The final nil is ignored. If LIST contains no items, FN must
+accept no arguments as well, and reduce return the result of
+calling FN with no arguments. If LIST has only 1 item, it is
+returned and FN is not called.
+
+The first argument of FN is the new item, the second is the
+accumulated value.
+
+Note: this function works the same as `-reduce' but the operation
+associates from right instead of from left.
+
+See also: `-reduce-r-from', `-reduce'"
+  (cond
+   ((not list) (funcall fn))
+   ((not (cdr list)) (car list))
+   (t (funcall fn (car list) (-reduce-r fn (cdr list))))))
+
+(defmacro --reduce-r (form list)
+  "Anaphoric version of `-reduce-r'."
+  (declare (debug (form form)))
+  `(-reduce-r (lambda (&optional it acc) ,form) ,list))
+
+(defmacro --filter (form list)
+  "Anaphoric form of `-filter'."
+  (declare (debug (form form)))
+  (let ((r (make-symbol "result")))
+    `(let (,r)
+       (--each ,list (when ,form (!cons it ,r)))
+       (nreverse ,r))))
+
+(defun -filter (pred list)
+  "Return a new list of the items in LIST for which PRED returns a non-nil value.
+
+Alias: `-select'
+
+See also: `-keep'"
+  (--filter (funcall pred it) list))
+
+(defalias '-select '-filter)
+(defalias '--select '--filter)
+
+(defmacro --remove (form list)
+  "Anaphoric form of `-remove'."
+  (declare (debug (form form)))
+  `(--filter (not ,form) ,list))
+
+(defun -remove (pred list)
+  "Return a new list of the items in LIST for which PRED returns nil.
+
+Alias: `-reject'"
+  (--remove (funcall pred it) list))
+
+(defalias '-reject '-remove)
+(defalias '--reject '--remove)
+
+(defun -remove-first (pred list)
+  "Return a new list with the first item matching PRED removed.
+
+Alias: `-reject-first'
+
+See also: `-remove', `-map-first'"
+  (let (front)
+    (while (and list (not (funcall pred (car list))))
+      (push (car list) front)
+      (!cdr list))
+    (if list
+        (-concat (nreverse front) (cdr list))
+      (nreverse front))))
+
+(defmacro --remove-first (form list)
+  "Anaphoric form of `-remove-first'."
+  (declare (debug (form form)))
+  `(-remove-first (lambda (it) ,form) ,list))
+
+(defalias '-reject-first '-remove-first)
+(defalias '--reject-first '--remove-first)
+
+(defun -remove-last (pred list)
+  "Return a new list with the last item matching PRED removed.
+
+Alias: `-reject-last'
+
+See also: `-remove', `-map-last'"
+  (nreverse (-remove-first pred (nreverse list))))
+
+(defmacro --remove-last (form list)
+  "Anaphoric form of `-remove-last'."
+  (declare (debug (form form)))
+  `(-remove-last (lambda (it) ,form) ,list))
+
+(defalias '-reject-last '-remove-last)
+(defalias '--reject-last '--remove-last)
+
+(defun -remove-item (item list)
+  "Remove all occurences of ITEM from LIST.
+
+Comparison is done with `equal'."
+  (--remove (equal it item) list))
+
+(defmacro --keep (form list)
+  "Anaphoric form of `-keep'."
+  (declare (debug (form form)))
+  (let ((r (make-symbol "result"))
+        (m (make-symbol "mapped")))
+    `(let (,r)
+       (--each ,list (let ((,m ,form)) (when ,m (!cons ,m ,r))))
+       (nreverse ,r))))
+
+(defun -keep (fn list)
+  "Return a new list of the non-nil results of applying FN to the items in LIST.
+
+If you want to select the original items satisfying a predicate use `-filter'."
+  (--keep (funcall fn it) list))
+
+(defun -non-nil (list)
+  "Return all non-nil elements of LIST."
+  (-remove 'null list))
+
+(defmacro --map-indexed (form list)
+  "Anaphoric form of `-map-indexed'."
+  (declare (debug (form form)))
+  (let ((r (make-symbol "result")))
+    `(let (,r)
+       (--each ,list
+         (!cons ,form ,r))
+       (nreverse ,r))))
+
+(defun -map-indexed (fn list)
+  "Return a new list consisting of the result of (FN index item) for each item in LIST.
+
+In the anaphoric form `--map-indexed', the index is exposed as `it-index`."
+  (--map-indexed (funcall fn it-index it) list))
+
+(defmacro --map-when (pred rep list)
+  "Anaphoric form of `-map-when'."
+  (declare (debug (form form form)))
+  (let ((r (make-symbol "result")))
+    `(let (,r)
+       (--each ,list (!cons (if ,pred ,rep it) ,r))
+       (nreverse ,r))))
+
+(defun -map-when (pred rep list)
+  "Return a new list where the elements in LIST that does not match the PRED function
+are unchanged, and where the elements in LIST that do match the PRED function are mapped
+through the REP function.
+
+Alias: `-replace-where'
+
+See also: `-update-at'"
+  (--map-when (funcall pred it) (funcall rep it) list))
+
+(defalias '-replace-where '-map-when)
+(defalias '--replace-where '--map-when)
+
+(defun -map-first (pred rep list)
+  "Replace first item in LIST satisfying PRED with result of REP called on this item.
+
+See also: `-map-when', `-replace-first'"
+  (let (front)
+    (while (and list (not (funcall pred (car list))))
+      (push (car list) front)
+      (!cdr list))
+    (if list
+        (-concat (nreverse front) (cons (funcall rep (car list)) (cdr list)))
+      (nreverse front))))
+
+(defmacro --map-first (pred rep list)
+  "Anaphoric form of `-map-first'."
+  `(-map-first (lambda (it) ,pred) (lambda (it) (ignore it) ,rep) ,list))
+
+(defun -map-last (pred rep list)
+  "Replace first item in LIST satisfying PRED with result of REP called on this item.
+
+See also: `-map-when', `-replace-last'"
+  (nreverse (-map-first pred rep (nreverse list))))
+
+(defmacro --map-last (pred rep list)
+  "Anaphoric form of `-map-last'."
+  `(-map-last (lambda (it) ,pred) (lambda (it) (ignore it) ,rep) ,list))
+
+(defun -replace (old new list)
+  "Replace all OLD items in LIST with NEW.
+
+Elements are compared using `equal'.
+
+See also: `-replace-at'"
+  (--map-when (equal it old) new list))
+
+(defun -replace-first (old new list)
+  "Replace the first occurence of OLD with NEW in LIST.
+
+Elements are compared using `equal'.
+
+See also: `-map-first'"
+  (--map-first (equal old it) new list))
+
+(defun -replace-last (old new list)
+  "Replace the last occurence of OLD with NEW in LIST.
+
+Elements are compared using `equal'.
+
+See also: `-map-last'"
+  (--map-last (equal old it) new list))
+
+(defmacro --mapcat (form list)
+  "Anaphoric form of `-mapcat'."
+  (declare (debug (form form)))
+  `(apply 'append (--map ,form ,list)))
+
+(defun -mapcat (fn list)
+  "Return the concatenation of the result of mapping FN over LIST.
+Thus function FN should return a list."
+  (--mapcat (funcall fn it) list))
+
+(defun -flatten (l)
+  "Take a nested list L and return its contents as a single, flat list.
+
+Note that because `nil' represents a list of zero elements (an
+empty list), any mention of nil in L will disappear after
+flattening.  If you need to preserve nils, consider `-flatten-n'
+or map them to some unique symbol and then map them back.
+
+Conses of two atoms are considered \"terminals\", that is, they
+aren't flattened further.
+
+See also: `-flatten-n'"
+  (if (and (listp l) (listp (cdr l)))
+      (-mapcat '-flatten l)
+    (list l)))
+
+(defmacro --iterate (form init n)
+  "Anaphoric version of `-iterate'."
+  (declare (debug (form form form)))
+  `(-iterate (lambda (it) ,form) ,init ,n))
+
+(defun -flatten-n (num list)
+  "Flatten NUM levels of a nested LIST.
+
+See also: `-flatten'"
+  (-last-item (--iterate (--mapcat (-list it) it) list (1+ num))))
+
+(defun -concat (&rest lists)
+  "Return a new list with the concatenation of the elements in the supplied LISTS."
+  (apply 'append lists))
+
+(defalias '-copy 'copy-sequence
+  "Create a shallow copy of LIST.")
+
+(defun -splice (pred fun list)
+  "Splice lists generated by FUN in place of elements matching PRED in LIST.
+
+FUN takes the element matching PRED as input.
+
+This function can be used as replacement for `,@' in case you
+need to splice several lists at marked positions (for example
+with keywords).
+
+See also: `-splice-list', `-insert-at'"
+  (let (r)
+    (--each list
+      (if (funcall pred it)
+          (let ((new (funcall fun it)))
+            (--each new (!cons it r)))
+        (!cons it r)))
+    (nreverse r)))
+
+(defmacro --splice (pred form list)
+  "Anaphoric form of `-splice'."
+  `(-splice (lambda (it) ,pred) (lambda (it) ,form) ,list))
+
+(defun -splice-list (pred new-list list)
+  "Splice NEW-LIST in place of elements matching PRED in LIST.
+
+See also: `-splice', `-insert-at'"
+  (-splice pred (lambda (_) new-list) list))
+
+(defmacro --splice-list (pred new-list list)
+  "Anaphoric form of `-splice-list'."
+  `(-splice-list (lambda (it) ,pred) ,new-list ,list))
+
+(defun -cons* (&rest args)
+  "Make a new list from the elements of ARGS.
+
+The last 2 members of ARGS are used as the final cons of the
+result so if the final member of ARGS is not a list the result is
+a dotted list."
+  (-reduce-r 'cons args))
+
+(defun -snoc (list elem &rest elements)
+  "Append ELEM to the end of the list.
+
+This is like `cons', but operates on the end of list.
+
+If ELEMENTS is non nil, append these to the list as well."
+  (-concat list (list elem) elements))
+
+(defmacro --first (form list)
+  "Anaphoric form of `-first'."
+  (declare (debug (form form)))
+  (let ((n (make-symbol "needle")))
+    `(let (,n)
+       (--each-while ,list (not ,n)
+         (when ,form (setq ,n it)))
+       ,n)))
+
+(defun -first (pred list)
+  "Return the first x in LIST where (PRED x) is non-nil, else nil.
+
+To get the first item in the list no questions asked, use `car'.
+
+Alias: `-find'"
+  (--first (funcall pred it) list))
+
+(defalias '-find '-first)
+(defalias '--find '--first)
+
+(defmacro --some (form list)
+  "Anaphoric form of `-some'."
+  (declare (debug (form form)))
+  (let ((n (make-symbol "needle")))
+    `(let (,n)
+       (--each-while ,list (not ,n)
+         (setq ,n ,form))
+       ,n)))
+
+(defun -some (pred list)
+  "Return (PRED x) for the first LIST item where (PRED x) is non-nil, else nil.
+
+Alias: `-any'"
+  (--some (funcall pred it) list))
+
+(defalias '-any '-some)
+(defalias '--any '--some)
+
+(defmacro --last (form list)
+  "Anaphoric form of `-last'."
+  (declare (debug (form form)))
+  (let ((n (make-symbol "needle")))
+    `(let (,n)
+       (--each ,list
+         (when ,form (setq ,n it)))
+       ,n)))
+
+(defun -last (pred list)
+  "Return the last x in LIST where (PRED x) is non-nil, else nil."
+  (--last (funcall pred it) list))
+
+(defalias '-first-item 'car
+  "Return the first item of LIST, or nil on an empty list.")
+
+(defun -last-item (list)
+  "Return the last item of LIST, or nil on an empty list."
+  (car (last list)))
+
+(defun -butlast (list)
+  "Return a list of all items in list except for the last."
+  (let (result)
+    (while (cdr list)
+      (!cons (car list) result)
+      (!cdr list))
+    (nreverse result)))
+
+(defmacro --count (pred list)
+  "Anaphoric form of `-count'."
+  (declare (debug (form form)))
+  (let ((r (make-symbol "result")))
+    `(let ((,r 0))
+       (--each ,list (when ,pred (setq ,r (1+ ,r))))
+       ,r)))
+
+(defun -count (pred list)
+  "Counts the number of items in LIST where (PRED item) is non-nil."
+  (--count (funcall pred it) list))
+
+(defun ---truthy? (val)
+  (not (null val)))
+
+(defmacro --any? (form list)
+  "Anaphoric form of `-any?'."
+  (declare (debug (form form)))
+  `(---truthy? (--first ,form ,list)))
+
+(defun -any? (pred list)
+  "Return t if (PRED x) is non-nil for any x in LIST, else nil.
+
+Alias: `-any-p', `-some?', `-some-p'"
+  (--any? (funcall pred it) list))
+
+(defalias '-some? '-any?)
+(defalias '--some? '--any?)
+(defalias '-any-p '-any?)
+(defalias '--any-p '--any?)
+(defalias '-some-p '-any?)
+(defalias '--some-p '--any?)
+
+(defmacro --all? (form list)
+  "Anaphoric form of `-all?'."
+  (declare (debug (form form)))
+  (let ((a (make-symbol "all")))
+    `(let ((,a t))
+       (--each-while ,list ,a (setq ,a ,form))
+       (---truthy? ,a))))
+
+(defun -all? (pred list)
+  "Return t if (PRED x) is non-nil for all x in LIST, else nil.
+
+Alias: `-all-p', `-every?', `-every-p'"
+  (--all? (funcall pred it) list))
+
+(defalias '-every? '-all?)
+(defalias '--every? '--all?)
+(defalias '-all-p '-all?)
+(defalias '--all-p '--all?)
+(defalias '-every-p '-all?)
+(defalias '--every-p '--all?)
+
+(defmacro --none? (form list)
+  "Anaphoric form of `-none?'."
+  (declare (debug (form form)))
+  `(--all? (not ,form) ,list))
+
+(defun -none? (pred list)
+  "Return t if (PRED x) is nil for all x in LIST, else nil.
+
+Alias: `-none-p'"
+  (--none? (funcall pred it) list))
+
+(defalias '-none-p '-none?)
+(defalias '--none-p '--none?)
+
+(defmacro --only-some? (form list)
+  "Anaphoric form of `-only-some?'."
+  (declare (debug (form form)))
+  (let ((y (make-symbol "yes"))
+        (n (make-symbol "no")))
+    `(let (,y ,n)
+       (--each-while ,list (not (and ,y ,n))
+         (if ,form (setq ,y t) (setq ,n t)))
+       (---truthy? (and ,y ,n)))))
+
+(defun -only-some? (pred list)
+  "Return `t` if at least one item of LIST matches PRED and at least one item of LIST does not match PRED.
+Return `nil` both if all items match the predicate or if none of the items match the predicate.
+
+Alias: `-only-some-p'"
+  (--only-some? (funcall pred it) list))
+
+(defalias '-only-some-p '-only-some?)
+(defalias '--only-some-p '--only-some?)
+
+(defun -slice (list from &optional to step)
+  "Return copy of LIST, starting from index FROM to index TO.
+
+FROM or TO may be negative.  These values are then interpreted
+modulo the length of the list.
+
+If STEP is a number, only each STEPth item in the resulting
+section is returned.  Defaults to 1."
+  (let ((length (length list))
+        (new-list nil))
+    ;; to defaults to the end of the list
+    (setq to (or to length))
+    (setq step (or step 1))
+    ;; handle negative indices
+    (when (< from 0)
+      (setq from (mod from length)))
+    (when (< to 0)
+      (setq to (mod to length)))
+
+    ;; iterate through the list, keeping the elements we want
+    (--each-while list (< it-index to)
+      (when (and (>= it-index from)
+                 (= (mod (- from it-index) step) 0))
+        (push it new-list)))
+    (nreverse new-list)))
+
+(defun -take (n list)
+  "Return a new list of the first N items in LIST, or all items if there are fewer than N."
+  (let (result)
+    (--dotimes n
+      (when list
+        (!cons (car list) result)
+        (!cdr list)))
+    (nreverse result)))
+
+(defalias '-drop 'nthcdr "Return the tail of LIST without the first N items.")
+
+(defmacro --take-while (form list)
+  "Anaphoric form of `-take-while'."
+  (declare (debug (form form)))
+  (let ((r (make-symbol "result")))
+    `(let (,r)
+       (--each-while ,list ,form (!cons it ,r))
+       (nreverse ,r))))
+
+(defun -take-while (pred list)
+  "Return a new list of successive items from LIST while (PRED item) returns a non-nil value."
+  (--take-while (funcall pred it) list))
+
+(defmacro --drop-while (form list)
+  "Anaphoric form of `-drop-while'."
+  (declare (debug (form form)))
+  (let ((l (make-symbol "list")))
+    `(let ((,l ,list))
+       (while (and ,l (let ((it (car ,l))) ,form))
+         (!cdr ,l))
+       ,l)))
+
+(defun -drop-while (pred list)
+  "Return the tail of LIST starting from the first item for which (PRED item) returns nil."
+  (--drop-while (funcall pred it) list))
+
+(defun -split-at (n list)
+  "Return a list of ((-take N LIST) (-drop N LIST)), in no more than one pass through the list."
+  (let (result)
+    (--dotimes n
+      (when list
+        (!cons (car list) result)
+        (!cdr list)))
+    (list (nreverse result) list)))
+
+(defun -rotate (n list)
+  "Rotate LIST N places to the right.  With N negative, rotate to the left.
+The time complexity is O(n)."
+  (if (> n 0)
+      (append (last list n) (butlast list n))
+    (append (-drop (- n) list) (-take (- n) list))))
+
+(defun -insert-at (n x list)
+  "Return a list with X inserted into LIST at position N.
+
+See also: `-splice', `-splice-list'"
+  (let ((split-list (-split-at n list)))
+    (nconc (car split-list) (cons x (cadr split-list)))))
+
+(defun -replace-at (n x list)
+  "Return a list with element at Nth position in LIST replaced with X.
+
+See also: `-replace'"
+  (let ((split-list (-split-at n list)))
+    (nconc (car split-list) (cons x (cdr (cadr split-list))))))
+
+(defun -update-at (n func list)
+  "Return a list with element at Nth position in LIST replaced with `(func (nth n list))`.
+
+See also: `-map-when'"
+  (let ((split-list (-split-at n list)))
+    (nconc (car split-list) (cons (funcall func (car (cadr split-list))) (cdr (cadr split-list))))))
+
+(defmacro --update-at (n form list)
+  "Anaphoric version of `-update-at'."
+  (declare (debug (form form form)))
+  `(-update-at ,n (lambda (it) ,form) ,list))
+
+(defun -remove-at (n list)
+  "Return a list with element at Nth position in LIST removed.
+
+See also: `-remove-at-indices', `-remove'"
+  (-remove-at-indices (list n) list))
+
+(defun -remove-at-indices (indices list)
+  "Return a list whose elements are elements from LIST without
+elements selected as `(nth i list)` for all i
+from INDICES.
+
+See also: `-remove-at', `-remove'"
+  (let* ((indices (-sort '< indices))
+         (diffs (cons (car indices) (-map '1- (-zip-with '- (cdr indices) indices))))
+         r)
+    (--each diffs
+      (let ((split (-split-at it list)))
+        (!cons (car split) r)
+        (setq list (cdr (cadr split)))))
+    (!cons list r)
+    (apply '-concat (nreverse r))))
+
+(defmacro --split-with (pred list)
+  "Anaphoric form of `-split-with'."
+  (declare (debug (form form)))
+  (let ((l (make-symbol "list"))
+        (r (make-symbol "result"))
+        (c (make-symbol "continue")))
+    `(let ((,l ,list)
+           (,r nil)
+           (,c t))
+       (while (and ,l ,c)
+         (let ((it (car ,l)))
+           (if (not ,pred)
+               (setq ,c nil)
+             (!cons it ,r)
+             (!cdr ,l))))
+       (list (nreverse ,r) ,l))))
+
+(defun -split-with (pred list)
+  "Return a list of ((-take-while PRED LIST) (-drop-while PRED LIST)), in no more than one pass through the list."
+  (--split-with (funcall pred it) list))
+
+(defmacro -split-on (item list)
+  "Split the LIST each time ITEM is found.
+
+Unlike `-partition-by', the ITEM is discarded from the results.
+Empty lists are also removed from the result.
+
+Comparison is done by `equal'.
+
+See also `-split-when'"
+  (declare (debug (form form)))
+  `(-split-when (lambda (it) (equal it ,item)) ,list))
+
+(defmacro --split-when (form list)
+  "Anaphoric version of `-split-when'."
+  (declare (debug (form form)))
+  `(-split-when (lambda (it) ,form) ,list))
+
+(defun -split-when (fn list)
+  "Split the LIST on each element where FN returns non-nil.
+
+Unlike `-partition-by', the \"matched\" element is discarded from
+the results.  Empty lists are also removed from the result.
+
+This function can be thought of as a generalization of
+`split-string'."
+  (let (r s)
+    (while list
+      (if (not (funcall fn (car list)))
+          (push (car list) s)
+        (when s (push (nreverse s) r))
+        (setq s nil))
+      (!cdr list))
+    (when s (push (nreverse s) r))
+    (nreverse r)))
+
+(defmacro --separate (form list)
+  "Anaphoric form of `-separate'."
+  (declare (debug (form form)))
+  (let ((y (make-symbol "yes"))
+        (n (make-symbol "no")))
+    `(let (,y ,n)
+       (--each ,list (if ,form (!cons it ,y) (!cons it ,n)))
+       (list (nreverse ,y) (nreverse ,n)))))
+
+(defun -separate (pred list)
+  "Return a list of ((-filter PRED LIST) (-remove PRED LIST)), in one pass through the list."
+  (--separate (funcall pred it) list))
+
+(defun ---partition-all-in-steps-reversed (n step list)
+  "Private: Used by -partition-all-in-steps and -partition-in-steps."
+  (when (< step 1)
+    (error "Step must be a positive number, or you're looking at some juicy infinite loops."))
+  (let ((result nil))
+    (while list
+      (!cons (-take n list) result)
+      (setq list (-drop step list)))
+    result))
+
+(defun -partition-all-in-steps (n step list)
+  "Return a new list with the items in LIST grouped into N-sized sublists at offsets STEP apart.
+The last groups may contain less than N items."
+  (nreverse (---partition-all-in-steps-reversed n step list)))
+
+(defun -partition-in-steps (n step list)
+  "Return a new list with the items in LIST grouped into N-sized sublists at offsets STEP apart.
+If there are not enough items to make the last group N-sized,
+those items are discarded."
+  (let ((result (---partition-all-in-steps-reversed n step list)))
+    (while (and result (< (length (car result)) n))
+      (!cdr result))
+    (nreverse result)))
+
+(defun -partition-all (n list)
+  "Return a new list with the items in LIST grouped into N-sized sublists.
+The last group may contain less than N items."
+  (-partition-all-in-steps n n list))
+
+(defun -partition (n list)
+  "Return a new list with the items in LIST grouped into N-sized sublists.
+If there are not enough items to make the last group N-sized,
+those items are discarded."
+  (-partition-in-steps n n list))
+
+(defmacro --partition-by (form list)
+  "Anaphoric form of `-partition-by'."
+  (declare (debug (form form)))
+  (let ((r (make-symbol "result"))
+        (s (make-symbol "sublist"))
+        (v (make-symbol "value"))
+        (n (make-symbol "new-value"))
+        (l (make-symbol "list")))
+    `(let ((,l ,list))
+       (when ,l
+         (let* ((,r nil)
+                (it (car ,l))
+                (,s (list it))
+                (,v ,form)
+                (,l (cdr ,l)))
+           (while ,l
+             (let* ((it (car ,l))
+                    (,n ,form))
+               (unless (equal ,v ,n)
+                 (!cons (nreverse ,s) ,r)
+                 (setq ,s nil)
+                 (setq ,v ,n))
+               (!cons it ,s)
+               (!cdr ,l)))
+           (!cons (nreverse ,s) ,r)
+           (nreverse ,r))))))
+
+(defun -partition-by (fn list)
+  "Apply FN to each item in LIST, splitting it each time FN returns a new value."
+  (--partition-by (funcall fn it) list))
+
+(defmacro --partition-by-header (form list)
+  "Anaphoric form of `-partition-by-header'."
+  (declare (debug (form form)))
+  (let ((r (make-symbol "result"))
+        (s (make-symbol "sublist"))
+        (h (make-symbol "header-value"))
+        (b (make-symbol "seen-body?"))
+        (n (make-symbol "new-value"))
+        (l (make-symbol "list")))
+    `(let ((,l ,list))
+       (when ,l
+         (let* ((,r nil)
+                (it (car ,l))
+                (,s (list it))
+                (,h ,form)
+                (,b nil)
+                (,l (cdr ,l)))
+           (while ,l
+             (let* ((it (car ,l))
+                    (,n ,form))
+               (if (equal ,h ,n)
+                   (when ,b
+                     (!cons (nreverse ,s) ,r)
+                     (setq ,s nil)
+                     (setq ,b nil))
+                 (setq ,b t))
+               (!cons it ,s)
+               (!cdr ,l)))
+           (!cons (nreverse ,s) ,r)
+           (nreverse ,r))))))
+
+(defun -partition-by-header (fn list)
+  "Apply FN to the first item in LIST. That is the header
+value. Apply FN to each item in LIST, splitting it each time FN
+returns the header value, but only after seeing at least one
+other value (the body)."
+  (--partition-by-header (funcall fn it) list))
+
+(defmacro --group-by (form list)
+  "Anaphoric form of `-group-by'."
+  (declare (debug t))
+  (let ((n (make-symbol "n"))
+        (k (make-symbol "k"))
+        (grp (make-symbol "grp")))
+    `(nreverse
+      (-map
+       (lambda (,n)
+         (cons (car ,n)
+               (nreverse (cdr ,n))))
+       (--reduce-from
+        (let* ((,k (,@form))
+               (,grp (assoc ,k acc)))
+          (if ,grp
+              (setcdr ,grp (cons it (cdr ,grp)))
+            (push
+             (list ,k it)
+             acc))
+          acc)
+        nil ,list)))))
+
+(defun -group-by (fn list)
+  "Separate LIST into an alist whose keys are FN applied to the
+elements of LIST.  Keys are compared by `equal'."
+  (--group-by (funcall fn it) list))
+
+(defun -interpose (sep list)
+  "Return a new list of all elements in LIST separated by SEP."
+  (let (result)
+    (when list
+      (!cons (car list) result)
+      (!cdr list))
+    (while list
+      (setq result (cons (car list) (cons sep result)))
+      (!cdr list))
+    (nreverse result)))
+
+(defun -interleave (&rest lists)
+  "Return a new list of the first item in each list, then the second etc."
+  (let (result)
+    (while (-none? 'null lists)
+      (--each lists (!cons (car it) result))
+      (setq lists (-map 'cdr lists)))
+    (nreverse result)))
+
+(defmacro --zip-with (form list1 list2)
+  "Anaphoric form of `-zip-with'.
+
+The elements in list1 is bound as `it`, the elements in list2 as `other`."
+  (declare (debug (form form form)))
+  (let ((r (make-symbol "result"))
+        (l1 (make-symbol "list1"))
+        (l2 (make-symbol "list2")))
+    `(let ((,r nil)
+           (,l1 ,list1)
+           (,l2 ,list2))
+       (while (and ,l1 ,l2)
+         (let ((it (car ,l1))
+               (other (car ,l2)))
+           (!cons ,form ,r)
+           (!cdr ,l1)
+           (!cdr ,l2)))
+       (nreverse ,r))))
+
+(defun -zip-with (fn list1 list2)
+  "Zip the two lists LIST1 and LIST2 using a function FN.  This
+function is applied pairwise taking as first argument element of
+LIST1 and as second argument element of LIST2 at corresponding
+position.
+
+The anaphoric form `--zip-with' binds the elements from LIST1 as `it`,
+and the elements from LIST2 as `other`."
+  (--zip-with (funcall fn it other) list1 list2))
+
+(defun -zip (&rest lists)
+  "Zip LISTS together.  Group the head of each list, followed by the
+second elements of each list, and so on. The lengths of the returned
+groupings are equal to the length of the shortest input list.
+
+If two lists are provided as arguments, return the groupings as a list
+of cons cells. Otherwise, return the groupings as a list of lists.
+
+Please note! This distinction is being removed in an upcoming 2.0
+release of Dash. If you rely on this behavior, use -zip-pair instead."
+  (let (results)
+    (while (-none? 'null lists)
+      (setq results (cons (mapcar 'car lists) results))
+      (setq lists (mapcar 'cdr lists)))
+    (setq results (nreverse results))
+    (if (= (length lists) 2)
+        ;; to support backward compatability, return
+        ;; a cons cell if two lists were provided
+        (--map (cons (car it) (cadr it)) results)
+      results)))
+
+(defalias '-zip-pair '-zip)
+
+(defun -zip-fill (fill-value &rest lists)
+  "Zip LISTS, with FILL-VALUE padded onto the shorter lists. The
+lengths of the returned groupings are equal to the length of the
+longest input list."
+  (apply '-zip (apply '-pad (cons fill-value lists))))
+
+(defun -cycle (list)
+  "Return an infinite copy of LIST that will cycle through the
+elements and repeat from the beginning."
+  (let ((newlist (-map 'identity list)))
+    (nconc newlist newlist)))
+
+(defun -pad (fill-value &rest lists)
+  "Appends FILL-VALUE to the end of each list in LISTS such that they
+will all have the same length."
+  (let* ((annotations (-annotate 'length lists))
+         (n (-max (-map 'car annotations))))
+    (--map (append (cdr it) (-repeat (- n (car it)) fill-value)) annotations)))
+
+(defun -annotate (fn list)
+  "Return a list of cons cells where each cell is FN applied to each
+element of LIST paired with the unmodified element of LIST."
+  (-zip (-map fn list) list))
+
+(defmacro --annotate (form list)
+  "Anaphoric version of `-annotate'."
+  (declare (debug (form form)))
+  `(-annotate (lambda (it) ,form) ,list))
+
+(defun dash--table-carry (lists restore-lists &optional re)
+  "Helper for `-table' and `-table-flat'.
+
+If a list overflows, carry to the right and reset the list."
+  (while (not (or (car lists)
+                  (equal lists '(nil))))
+    (setcar lists (car restore-lists))
+    (pop (cadr lists))
+    (!cdr lists)
+    (!cdr restore-lists)
+    (when re
+      (push (nreverse (car re)) (cadr re))
+      (setcar re nil)
+      (!cdr re))))
+
+(defun -table (fn &rest lists)
+  "Compute outer product of LISTS using function FN.
+
+The function FN should have the same arity as the number of
+supplied lists.
+
+The outer product is computed by applying fn to all possible
+combinations created by taking one element from each list in
+order.  The dimension of the result is (length lists).
+
+See also: `-table-flat'"
+  (let ((restore-lists (copy-sequence lists))
+        (last-list (last lists))
+        (re (make-list (length lists) nil)))
+    (while (car last-list)
+      (let ((item (apply fn (-map 'car lists))))
+        (push item (car re))
+        (setcar lists (cdar lists)) ;; silence byte compiler
+        (dash--table-carry lists restore-lists re)))
+    (nreverse (car (last re)))))
+
+(defun -table-flat (fn &rest lists)
+  "Compute flat outer product of LISTS using function FN.
+
+The function FN should have the same arity as the number of
+supplied lists.
+
+The outer product is computed by applying fn to all possible
+combinations created by taking one element from each list in
+order.  The results are flattened, ignoring the tensor structure
+of the result.  This is equivalent to calling:
+
+  (-flatten-n (1- (length lists)) (-table fn lists))
+
+but the implementation here is much more efficient.
+
+See also: `-flatten-n', `-table'"
+  (when lists                           ;Just in case.
+    (let* ((list1 (pop lists))
+           (restore-lists (copy-sequence lists))
+           (last-list (last lists))
+           re)
+      (while (car last-list)
+        (let ((tail (-map #'car lists)))
+          (dolist (head list1)
+            (push (apply fn head tail) re)))
+        (pop (car lists))
+        (dash--table-carry lists restore-lists))
+      (nreverse re))))
+
+(defun -partial (fn &rest args)
+  "Take a function FN and fewer than the normal arguments to FN,
+and return a fn that takes a variable number of additional ARGS.
+When called, the returned function calls FN with ARGS first and
+then additional args."
+  (apply 'apply-partially fn args))
+
+(defun -elem-index (elem list)
+  "Return the index of the first element in the given LIST which
+is equal to the query element ELEM, or nil if there is no
+such element."
+  (car (-elem-indices elem list)))
+
+(defun -elem-indices (elem list)
+  "Return the indices of all elements in LIST equal to the query
+element ELEM, in ascending order."
+  (-find-indices (-partial 'equal elem) list))
+
+(defun -find-indices (pred list)
+  "Return the indices of all elements in LIST satisfying the
+predicate PRED, in ascending order."
+  (apply 'append (--map-indexed (when (funcall pred it) (list it-index)) list)))
+
+(defmacro --find-indices (form list)
+  "Anaphoric version of `-find-indices'."
+  (declare (debug (form form)))
+  `(-find-indices (lambda (it) ,form) ,list))
+
+(defun -find-index (pred list)
+  "Take a predicate PRED and a LIST and return the index of the
+first element in the list satisfying the predicate, or nil if
+there is no such element."
+  (car (-find-indices pred list)))
+
+(defmacro --find-index (form list)
+  "Anaphoric version of `-find-index'."
+  (declare (debug (form form)))
+  `(-find-index (lambda (it) ,form) ,list))
+
+(defun -find-last-index (pred list)
+  "Take a predicate PRED and a LIST and return the index of the
+last element in the list satisfying the predicate, or nil if
+there is no such element."
+  (-last-item (-find-indices pred list)))
+
+(defmacro --find-last-index (form list)
+  "Anaphoric version of `-find-last-index'."
+  `(-find-last-index (lambda (it) ,form) ,list))
+
+(defun -select-by-indices (indices list)
+  "Return a list whose elements are elements from LIST selected
+as `(nth i list)` for all i from INDICES."
+  (let (r)
+    (--each indices
+      (!cons (nth it list) r))
+    (nreverse r)))
+
+(defmacro -> (x &optional form &rest more)
+  "Thread the expr through the forms. Insert X as the second item
+in the first form, making a list of it if it is not a list
+already. If there are more forms, insert the first form as the
+second item in second form, etc."
+  (cond
+   ((null form) x)
+   ((null more) (if (listp form)
+                    `(,(car form) ,x ,@(cdr form))
+                  (list form x)))
+   (:else `(-> (-> ,x ,form) ,@more))))
+
+(defmacro ->> (x &optional form &rest more)
+  "Thread the expr through the forms. Insert X as the last item
+in the first form, making a list of it if it is not a list
+already. If there are more forms, insert the first form as the
+last item in second form, etc."
+  (cond
+   ((null form) x)
+   ((null more) (if (listp form)
+                    `(,@form ,x)
+                  (list form x)))
+   (:else `(->> (->> ,x ,form) ,@more))))
+
+(defmacro --> (x form &rest more)
+  "Thread the expr through the forms. Insert X at the position
+signified by the token `it' in the first form. If there are more
+forms, insert the first form at the position signified by `it' in
+in second form, etc."
+  (if (null more)
+      (if (listp form)
+          (--map-when (eq it 'it) x form)
+        (list form x))
+    `(--> (--> ,x ,form) ,@more)))
+
+(defmacro -some-> (x &optional form &rest more)
+  "When expr is non-nil, thread it through the first form (via `->'),
+and when that result is non-nil, through the next form, etc."
+  (if (null form) x
+    (let ((result (make-symbol "result")))
+      `(-some-> (-when-let (,result ,x)
+                  (-> ,result ,form))
+                ,@more))))
+
+(defmacro -some->> (x &optional form &rest more)
+  "When expr is non-nil, thread it through the first form (via `->>'),
+and when that result is non-nil, through the next form, etc."
+  (if (null form) x
+    (let ((result (make-symbol "result")))
+      `(-some->> (-when-let (,result ,x)
+                   (->> ,result ,form))
+                 ,@more))))
+
+(defmacro -some--> (x &optional form &rest more)
+  "When expr in non-nil, thread it through the first form (via `-->'),
+and when that result is non-nil, through the next form, etc."
+  (if (null form) x
+    (let ((result (make-symbol "result")))
+      `(-some--> (-when-let (,result ,x)
+                   (--> ,result ,form))
+                 ,@more))))
+
+(defun -grade-up (comparator list)
+  "Grade elements of LIST using COMPARATOR relation, yielding a
+permutation vector such that applying this permutation to LIST
+sorts it in ascending order."
+  ;; ugly hack to "fix" lack of lexical scope
+  (let ((comp `(lambda (it other) (funcall ',comparator (car it) (car other)))))
+    (->> (--map-indexed (cons it it-index) list)
+         (-sort comp)
+         (-map 'cdr))))
+
+(defun -grade-down (comparator list)
+  "Grade elements of LIST using COMPARATOR relation, yielding a
+permutation vector such that applying this permutation to LIST
+sorts it in descending order."
+  ;; ugly hack to "fix" lack of lexical scope
+  (let ((comp `(lambda (it other) (funcall ',comparator (car other) (car it)))))
+    (->> (--map-indexed (cons it it-index) list)
+         (-sort comp)
+         (-map 'cdr))))
+
+(defvar dash--source-counter 0
+  "Monotonic counter for generated symbols.")
+
+(defun dash--match-make-source-symbol ()
+  "Generate a new dash-source symbol.
+
+All returned symbols are guaranteed to be unique."
+  (prog1 (make-symbol (format "--dash-source-%d--" dash--source-counter))
+    (setq dash--source-counter (1+ dash--source-counter))))
+
+(defun dash--match-ignore-place-p (symbol)
+  "Return non-nil if SYMBOL is a symbol and starts with _."
+  (and (symbolp symbol)
+       (eq (aref (symbol-name symbol) 0) ?_)))
+
+(defun dash--match-cons-skip-cdr (skip-cdr source)
+  "Helper function generating idiomatic shifting code."
+  (cond
+   ((= skip-cdr 0)
+    `(pop ,source))
+   (t
+    `(prog1 ,(dash--match-cons-get-car skip-cdr source)
+       (setq ,source ,(dash--match-cons-get-cdr (1+ skip-cdr) source))))))
+
+(defun dash--match-cons-get-car (skip-cdr source)
+  "Helper function generating idiomatic code to get nth car."
+  (cond
+   ((= skip-cdr 0)
+    `(car ,source))
+   ((= skip-cdr 1)
+    `(cadr ,source))
+   (t
+    `(nth ,skip-cdr ,source))))
+
+(defun dash--match-cons-get-cdr (skip-cdr source)
+  "Helper function generating idiomatic code to get nth cdr."
+  (cond
+   ((= skip-cdr 0)
+    source)
+   ((= skip-cdr 1)
+    `(cdr ,source))
+   (t
+    `(nthcdr ,skip-cdr ,source))))
+
+(defun dash--match-cons (match-form source)
+  "Setup a cons matching environment and call the real matcher."
+  (let ((s (dash--match-make-source-symbol))
+        (n 0)
+        (m match-form))
+    (while (and (consp m)
+                (dash--match-ignore-place-p (car m)))
+      (setq n (1+ n)) (!cdr m))
+    (cond
+     ;; when we only have one pattern in the list, we don't have to
+     ;; create a temporary binding (--dash-source--) for the source
+     ;; and just use the input directly
+     ((and (consp m)
+           (not (cdr m)))
+      (dash--match (car m) (dash--match-cons-get-car n source)))
+     ;; handle other special types
+     ((> n 0)
+      (dash--match m (dash--match-cons-get-cdr n source)))
+     ;; this is the only entry-point for dash--match-cons-1, that's
+     ;; why we can't simply use the above branch, it would produce
+     ;; infinite recursion
+     (t
+      (cons (list s source) (dash--match-cons-1 match-form s))))))
+
+(defun dash--match-cons-1 (match-form source &optional props)
+  "Match MATCH-FORM against SOURCE.
+
+MATCH-FORM is a proper or improper list.  Each element of
+MATCH-FORM is either a symbol, which gets bound to the respective
+value in source or another match form which gets destructured
+recursively.
+
+If the cdr of last cons cell in the list is `nil', matching stops
+there.
+
+SOURCE is a proper or improper list."
+  (let ((skip-cdr (or (plist-get props :skip-cdr) 0)))
+    (cond
+     ((consp match-form)
+      (cond
+       ((cdr match-form)
+        (cond
+         ((and (symbolp (car match-form))
+               (memq (car match-form) '(&keys &plist &alist &hash)))
+          (dash--match-kv match-form (dash--match-cons-get-cdr skip-cdr source)))
+         ((dash--match-ignore-place-p (car match-form))
+          (dash--match-cons-1 (cdr match-form) source
+                              (plist-put props :skip-cdr (1+ skip-cdr))))
+         (t
+          (-concat (dash--match (car match-form) (dash--match-cons-skip-cdr skip-cdr source))
+                   (dash--match-cons-1 (cdr match-form) source)))))
+       (t ;; Last matching place, no need for shift
+        (dash--match (car match-form) (dash--match-cons-get-car skip-cdr source)))))
+     ((eq match-form nil)
+      nil)
+     (t ;; Handle improper lists.  Last matching place, no need for shift
+      (dash--match match-form (dash--match-cons-get-cdr skip-cdr source))))))
+
+(defun dash--vector-tail (seq start)
+  "Return the tail of SEQ starting at START."
+  (cond
+   ((vectorp seq)
+    (let* ((re-length (- (length seq) start))
+           (re (make-vector re-length 0)))
+      (--dotimes re-length (aset re it (aref seq (+ it start))))
+      re))
+   ((stringp seq)
+    (substring seq start))))
+
+(defun dash--match-vector (match-form source)
+  "Setup a vector matching environment and call the real matcher."
+  (let ((s (dash--match-make-source-symbol)))
+    (cond
+     ;; don't bind `s' if we only have one sub-pattern
+     ((= (length match-form) 1)
+      (dash--match (aref match-form 0) `(aref ,source 0)))
+     ;; if the source is a symbol, we don't need to re-bind it
+     ((symbolp source)
+      (dash--match-vector-1 match-form source))
+     ;; don't bind `s' if we only have one sub-pattern which is not ignored
+     ((let* ((ignored-places (mapcar 'dash--match-ignore-place-p match-form))
+             (ignored-places-n (length (-remove 'null ignored-places))))
+        (when (= ignored-places-n (1- (length match-form)))
+          (let ((n (-find-index 'null ignored-places)))
+            (dash--match (aref match-form n) `(aref ,source ,n))))))
+     (t
+      (cons (list s source) (dash--match-vector-1 match-form s))))))
+
+(defun dash--match-vector-1 (match-form source)
+  "Match MATCH-FORM against SOURCE.
+
+MATCH-FORM is a vector.  Each element of MATCH-FORM is either a
+symbol, which gets bound to the respective value in source or
+another match form which gets destructured recursively.
+
+If second-from-last place in MATCH-FORM is the symbol &rest, the
+next element of the MATCH-FORM is matched against the tail of
+SOURCE, starting at index of the &rest symbol.  This is
+conceptually the same as the (head . tail) match for improper
+lists, where dot plays the role of &rest.
+
+SOURCE is a vector.
+
+If the MATCH-FORM vector is shorter than SOURCE vector, only
+the (length MATCH-FORM) places are bound, the rest of the SOURCE
+is discarded."
+  (let ((i 0)
+        (l (length match-form))
+        (re))
+    (while (< i l)
+      (let ((m (aref match-form i)))
+        (push (cond
+               ((and (symbolp m)
+                     (eq m '&rest))
+                (prog1 (dash--match
+                        (aref match-form (1+ i))
+                        `(dash--vector-tail ,source ,i))
+                  (setq i l)))
+               ((and (symbolp m)
+                     ;; do not match symbols starting with _
+                     (not (eq (aref (symbol-name m) 0) ?_)))
+                (list (list m `(aref ,source ,i))))
+               ((not (symbolp m))
+                (dash--match m `(aref ,source ,i))))
+              re)
+        (setq i (1+ i))))
+    (-flatten-n 1 (nreverse re))))
+
+(defun dash--match-kv (match-form source)
+  "Setup a kv matching environment and call the real matcher.
+
+kv can be any key-value store, such as plist, alist or hash-table."
+  (let ((s (dash--match-make-source-symbol)))
+    (cond
+     ;; don't bind `s' if we only have one sub-pattern (&type key val)
+     ((= (length match-form) 3)
+      (dash--match-kv-1 (cdr match-form) source (car match-form)))
+     ;; if the source is a symbol, we don't need to re-bind it
+     ((symbolp source)
+      (dash--match-kv-1 (cdr match-form) source (car match-form)))
+     (t
+      (cons (list s source) (dash--match-kv-1 (cdr match-form) s (car match-form)))))))
+
+(defun dash--match-kv-1 (match-form source type)
+  "Match MATCH-FORM against SOURCE of type TYPE.
+
+MATCH-FORM is a proper list of the form (key1 place1 ... keyN
+placeN).  Each placeK is either a symbol, which gets bound to the
+value of keyK retrieved from the key-value store, or another
+match form which gets destructured recursively.
+
+SOURCE is a key-value store of type TYPE, which can be a plist,
+an alist or a hash table.
+
+TYPE is a token specifying the type of the key-value store.
+Valid values are &plist, &alist and &hash."
+  (-flatten-n 1 (-map
+                 (lambda (kv)
+                   (let* ((k (car kv))
+                          (v (cadr kv))
+                          (getter (cond
+                                   ((or (eq type '&plist) (eq type '&keys))
+                                    `(plist-get ,source ,k))
+                                   ((eq type '&alist)
+                                    `(cdr (assoc ,k ,source)))
+                                   ((eq type '&hash)
+                                    `(gethash ,k ,source)))))
+                     (cond
+                      ((symbolp v)
+                       (list (list v getter)))
+                      (t (dash--match v getter)))))
+                 (-partition 2 match-form))))
+
+(defun dash--match-symbol (match-form source)
+  "Bind a symbol.
+
+This works just like `let', there is no destructuring."
+  (list (list match-form source)))
+
+(defun dash--match (match-form source)
+  "Match MATCH-FORM against SOURCE.
+
+This function tests the MATCH-FORM and dispatches to specific
+matchers based on the type of the expression.
+
+Key-value stores are disambiguated by placing a token &plist,
+&alist or &hash as a first item in the MATCH-FORM."
+  (cond
+   ((symbolp match-form)
+    (dash--match-symbol match-form source))
+   ((consp match-form)
+    (cond
+     ;; Handle the "x &as" bindings first.
+     ((and (consp (cdr match-form))
+           (symbolp (car match-form))
+           (eq '&as (cadr match-form)))
+      (let ((s (car match-form)))
+        (cons (list s source)
+              (dash--match (cddr match-form) s))))
+     ((memq (car match-form) '(&keys &plist &alist &hash))
+      (dash--match-kv match-form source))
+     (t (dash--match-cons match-form source))))
+   ((vectorp match-form)
+    ;; We support the &as binding in vectors too
+    (cond
+     ((and (> (length match-form) 2)
+           (symbolp (aref match-form 0))
+           (eq '&as (aref match-form 1)))
+      (let ((s (aref match-form 0)))
+        (cons (list s source)
+              (dash--match (dash--vector-tail match-form 2) s))))
+     (t (dash--match-vector match-form source))))))
+
+(defmacro -let* (varlist &rest body)
+  "Bind variables according to VARLIST then eval BODY.
+
+VARLIST is a list of lists of the form (PATTERN SOURCE).  Each
+PATTERN is matched against the SOURCE structurally.  SOURCE is
+only evaluated once for each PATTERN.
+
+Each SOURCE can refer to the symbols already bound by this
+VARLIST.  This is useful if you want to destructure SOURCE
+recursively but also want to name the intermediate structures.
+
+See `-let' for the list of all possible patterns."
+  (declare (debug ((&rest (sexp form)) body))
+           (indent 1))
+  (let ((bindings (--mapcat (dash--match (car it) (cadr it)) varlist)))
+    `(let* ,bindings
+       ,@body)))
+
+(defmacro -let (varlist &rest body)
+  "Bind variables according to VARLIST then eval BODY.
+
+VARLIST is a list of lists of the form (PATTERN SOURCE).  Each
+PATTERN is matched against the SOURCE \"structurally\".  SOURCE
+is only evaluated once for each PATTERN.  Each PATTERN is matched
+recursively, and can therefore contain sub-patterns which are
+matched against corresponding sub-expressions of SOURCE.
+
+All the SOURCEs are evalled before any symbols are
+bound (i.e. \"in parallel\").
+
+If VARLIST only contains one (PATTERN SOURCE) element, you can
+optionally specify it using a vector and discarding the
+outer-most parens.  Thus
+
+  (-let ((PATTERN SOURCE)) ..)
+
+becomes
+
+  (-let [PATTERN SOURCE] ..).
+
+`-let' uses a convention of not binding places (symbols) starting
+with _ whenever it's possible.  You can use this to skip over
+entries you don't care about.  However, this is not *always*
+possible (as a result of implementation) and these symbols might
+get bound to undefined values.
+
+Following is the overview of supported patterns.  Remember that
+patterns can be matched recursively, so every a, b, aK in the
+following can be a matching construct and not necessarily a
+symbol/variable.
+
+Symbol:
+
+  a - bind the SOURCE to A.  This is just like regular `let'.
+
+Conses and lists:
+
+  (a) - bind `car' of cons/list to A
+
+  (a . b) - bind car of cons to A and `cdr' to B
+
+  (a b) - bind car of list to A and `cadr' to B
+
+  (a1 a2 a3  ...) - bind 0th car of list to A1, 1st to A2, 2nd to A3 ...
+
+  (a1 a2 a3 ... aN . rest) - as above, but bind the Nth cdr to REST.
+
+Vectors:
+
+  [a] - bind 0th element of a non-list sequence to A (works with
+        vectors, strings, bit arrays...)
+
+  [a1 a2 a3 ...] - bind 0th element of non-list sequence to A0, 1st to
+                   A1, 2nd to A2, ...
+                   If the PATTERN is shorter than SOURCE, the values at
+                   places not in PATTERN are ignored.
+                   If the PATTERN is longer than SOURCE, an `error' is
+                   thrown.
+
+  [a1 a2 a3 ... &rest rest] - as above, but bind the rest of
+                              the sequence to REST.  This is
+                              conceptually the same as improper list
+                              matching (a1 a2 ... aN . rest)
+
+Key/value stores:
+
+  (&plist key0 a0 ... keyN aN) - bind value mapped by keyK in the
+                                 SOURCE plist to aK.  If the
+                                 value is not found, aK is nil.
+
+  (&alist key0 a0 ... keyN aN) - bind value mapped by keyK in the
+                                 SOURCE alist to aK.  If the
+                                 value is not found, aK is nil.
+
+  (&hash key0 a0 ... keyN aN) - bind value mapped by keyK in the
+                                SOURCE hash table to aK.  If the
+                                value is not found, aK is nil.
+
+Further, special keyword &keys supports \"inline\" matching of
+plist-like key-value pairs, similarly to &keys keyword of
+`cl-defun'.
+
+  (a1 a2 ... aN &keys key1 b1 ... keyN bK)
+
+This binds N values from the list to a1 ... aN, then interprets
+the cdr as a plist (see key/value matching above).
+
+You can name the source using the syntax SYMBOL &as PATTERN.
+This syntax works with lists (proper or improper), vectors and
+all types of maps.
+
+  (list &as a b c) (list 1 2 3)
+
+binds A to 1, B to 2, C to 3 and LIST to (1 2 3).
+
+Similarly:
+
+  (bounds &as beg . end) (cons 1 2)
+
+binds BEG to 1, END to 2 and BOUNDS to (1 . 2).
+
+  (items &as first . rest) (list 1 2 3)
+
+binds FIRST to 1, REST to (2 3) and ITEMS to (1 2 3)
+
+  [vect &as _ b c] [1 2 3]
+
+binds B to 2, C to 3 and VECT to [1 2 3] (_ avoids binding as usual).
+
+  (plist &as &plist :b b) (list :a 1 :b 2 :c 3)
+
+binds B to 2 and PLIST to (:a 1 :b 2 :c 3).  Same for &alist and &hash.
+
+This is especially useful when we want to capture the result of a
+computation and destructure at the same time.  Consider the
+form (function-returning-complex-structure) returning a list of
+two vectors with two items each.  We want to capture this entire
+result and pass it to another computation, but at the same time
+we want to get the second item from each vector.  We can achieve
+it with pattern
+
+  (result &as [_ a] [_ b]) (function-returning-complex-structure)
+
+Note: Clojure programmers may know this feature as the \":as
+binding\".  The difference is that we put the &as at the front
+because we need to support improper list binding."
+  (declare (debug ([&or (&rest (sexp form))
+                        (vector [&rest [sexp form]])]
+                   body))
+           (indent 1))
+  (if (vectorp varlist)
+      `(let* ,(dash--match (aref varlist 0) (aref varlist 1))
+         ,@body)
+    (let* ((inputs (--map-indexed (list (make-symbol (format "input%d" it-index)) (cadr it)) varlist))
+           (new-varlist (--map (list (caar it) (cadr it)) (-zip varlist inputs))))
+      `(let ,inputs
+         (-let* ,new-varlist ,@body)))))
+
+(defmacro -lambda (match-form &rest body)
+  "Return a lambda which destructures its input as MATCH-FORM and executes BODY.
+
+Note that you have to enclose the MATCH-FORM in a pair of parens,
+such that:
+
+  (-lambda (x) body)
+  (-lambda (x y ...) body)
+
+has the usual semantics of `lambda'.  Furthermore, these get
+translated into normal lambda, so there is no performance
+penalty.
+
+See `-let' for the description of destructuring mechanism."
+  (declare (doc-string 2) (indent defun)
+           (debug (&define sexp
+                           [&optional stringp]
+                           [&optional ("interactive" interactive)]
+                           def-body)))
+  (cond
+   ((not (consp match-form))
+    (signal 'wrong-type-argument "match-form must be a list"))
+   ;; no destructuring, so just return regular lambda to make things faster
+   ((-all? 'symbolp match-form)
+    `(lambda ,match-form ,@body))
+   (t
+    (let* ((inputs (--map-indexed (list it (make-symbol (format "input%d" it-index))) match-form)))
+      ;; TODO: because inputs to the lambda are evaluated only once,
+      ;; -let* need not to create the extra bindings to ensure that.
+      ;; We should find a way to optimize that.  Not critical however.
+      `(lambda ,(--map (cadr it) inputs)
+         (-let* ,inputs ,@body))))))
+
+(defmacro -if-let* (vars-vals then &rest else)
+  "If all VALS evaluate to true, bind them to their corresponding
+VARS and do THEN, otherwise do ELSE. VARS-VALS should be a list
+of (VAR VAL) pairs.
+
+Note: binding is done according to `-let*'.  VALS are evaluated
+sequentially, and evaluation stops after the first nil VAL is
+encountered."
+  (declare (debug ((&rest (sexp form)) form body))
+           (indent 2))
+  (->> vars-vals
+       (--mapcat (dash--match (car it) (cadr it)))
+       (--reduce-r-from
+        (let ((var (car it))
+              (val (cadr it)))
+          `(let ((,var ,val))
+             (if ,var ,acc ,@else)))
+        then)))
+
+(defmacro -if-let (var-val then &rest else)
+  "If VAL evaluates to non-nil, bind it to VAR and do THEN,
+otherwise do ELSE. VAR-VAL should be a (VAR VAL) pair.
+
+Note: binding is done according to `-let'."
+  (declare (debug ((sexp form) form body))
+           (indent 2))
+  `(-if-let* (,var-val) ,then ,@else))
+
+(defmacro --if-let (val then &rest else)
+  "If VAL evaluates to non-nil, bind it to `it' and do THEN,
+otherwise do ELSE."
+  (declare (debug (form form body))
+           (indent 2))
+  `(-if-let (it ,val) ,then ,@else))
+
+(defmacro -when-let* (vars-vals &rest body)
+  "If all VALS evaluate to true, bind them to their corresponding
+VARS and execute body. VARS-VALS should be a list of (VAR VAL)
+pairs.
+
+Note: binding is done according to `-let*'.  VALS are evaluated
+sequentially, and evaluation stops after the first nil VAL is
+encountered."
+  (declare (debug ((&rest (sexp form)) body))
+           (indent 1))
+  `(-if-let* ,vars-vals (progn ,@body)))
+
+(defmacro -when-let (var-val &rest body)
+  "If VAL evaluates to non-nil, bind it to VAR and execute body.
+VAR-VAL should be a (VAR VAL) pair.
+
+Note: binding is done according to `-let'."
+  (declare (debug ((sexp form) body))
+           (indent 1))
+  `(-if-let ,var-val (progn ,@body)))
+
+(defmacro --when-let (val &rest body)
+  "If VAL evaluates to non-nil, bind it to `it' and execute
+body."
+  (declare (debug (form body))
+           (indent 1))
+  `(--if-let ,val (progn ,@body)))
+
+(defvar -compare-fn nil
+  "Tests for equality use this function or `equal' if this is nil.
+It should only be set using dynamic scope with a let, like:
+
+  (let ((-compare-fn #'=)) (-union numbers1 numbers2 numbers3)")
+
+(defun -distinct (list)
+  "Return a new list with all duplicates removed.
+The test for equality is done with `equal',
+or with `-compare-fn' if that's non-nil.
+
+Alias: `-uniq'"
+  (let (result)
+    (--each list (unless (-contains? result it) (!cons it result)))
+    (nreverse result)))
+
+(defalias '-uniq '-distinct)
+
+(defun -union (list list2)
+  "Return a new list containing the elements of LIST1 and elements of LIST2 that are not in LIST1.
+The test for equality is done with `equal',
+or with `-compare-fn' if that's non-nil."
+  ;; We fall back to iteration implementation if the comparison
+  ;; function isn't one of `eq', `eql' or `equal'.
+  (let* ((result (reverse list))
+         ;; TODO: get rid of this dynamic variable, pass it as an
+         ;; argument instead.
+         (-compare-fn (if (bound-and-true-p -compare-fn)
+                          -compare-fn
+                        'equal)))
+    (if (memq -compare-fn '(eq eql equal))
+        (let ((ht (make-hash-table :test -compare-fn)))
+          (--each list (puthash it t ht))
+          (--each list2 (unless (gethash it ht) (!cons it result))))
+      (--each list2 (unless (-contains? result it) (!cons it result))))
+    (nreverse result)))
+
+(defun -intersection (list list2)
+  "Return a new list containing only the elements that are members of both LIST and LIST2.
+The test for equality is done with `equal',
+or with `-compare-fn' if that's non-nil."
+  (--filter (-contains? list2 it) list))
+
+(defun -difference (list list2)
+  "Return a new list with only the members of LIST that are not in LIST2.
+The test for equality is done with `equal',
+or with `-compare-fn' if that's non-nil."
+  (--filter (not (-contains? list2 it)) list))
+
+(defun -contains? (list element)
+  "Return non-nil if LIST contains ELEMENT.
+
+The test for equality is done with `equal', or with `-compare-fn'
+if that's non-nil.
+
+Alias: `-contains-p'"
+  (not
+   (null
+    (cond
+     ((null -compare-fn)    (member element list))
+     ((eq -compare-fn 'eq)  (memq element list))
+     ((eq -compare-fn 'eql) (memql element list))
+     (t
+      (let ((lst list))
+        (while (and lst
+                    (not (funcall -compare-fn element (car lst))))
+          (setq lst (cdr lst)))
+        lst))))))
+
+(defalias '-contains-p '-contains?)
+
+(defun -same-items? (list list2)
+  "Return true if LIST and LIST2 has the same items.
+
+The order of the elements in the lists does not matter.
+
+Alias: `-same-items-p'"
+  (let ((length-a (length list))
+        (length-b (length list2)))
+    (and
+     (= length-a length-b)
+     (= length-a (length (-intersection list list2))))))
+
+(defalias '-same-items-p '-same-items?)
+
+(defun -is-prefix? (prefix list)
+  "Return non-nil if PREFIX is prefix of LIST.
+
+Alias: `-is-prefix-p'"
+  (--each-while list (equal (car prefix) it)
+    (!cdr prefix))
+  (not prefix))
+
+(defun -is-suffix? (suffix list)
+  "Return non-nil if SUFFIX is suffix of LIST.
+
+Alias: `-is-suffix-p'"
+  (-is-prefix? (reverse suffix) (reverse list)))
+
+(defun -is-infix? (infix list)
+  "Return non-nil if INFIX is infix of LIST.
+
+This operation runs in O(n^2) time
+
+Alias: `-is-infix-p'"
+  (let (done)
+    (while (and (not done) list)
+      (setq done (-is-prefix? infix list))
+      (!cdr list))
+    done))
+
+(defalias '-is-prefix-p '-is-prefix?)
+(defalias '-is-suffix-p '-is-suffix?)
+(defalias '-is-infix-p '-is-infix?)
+
+(defun -sort (comparator list)
+  "Sort LIST, stably, comparing elements using COMPARATOR.
+Return the sorted list.  LIST is NOT modified by side effects.
+COMPARATOR is called with two elements of LIST, and should return non-nil
+if the first element should sort before the second."
+  (sort (copy-sequence list) comparator))
+
+(defmacro --sort (form list)
+  "Anaphoric form of `-sort'."
+  (declare (debug (form form)))
+  `(-sort (lambda (it other) ,form) ,list))
+
+(defun -list (&rest args)
+  "Return a list with ARGS.
+
+If first item of ARGS is already a list, simply return ARGS.  If
+not, return a list with ARGS as elements."
+  (let ((arg (car args)))
+    (if (listp arg) arg args)))
+
+(defun -repeat (n x)
+  "Return a list with X repeated N times.
+Return nil if N is less than 1."
+  (let (ret)
+    (--dotimes n (!cons x ret))
+    ret))
+
+(defun -sum (list)
+  "Return the sum of LIST."
+  (apply '+ list))
+
+(defun -product (list)
+  "Return the product of LIST."
+  (apply '* list))
+
+(defun -max (list)
+  "Return the largest value from LIST of numbers or markers."
+  (apply 'max list))
+
+(defun -min (list)
+  "Return the smallest value from LIST of numbers or markers."
+  (apply 'min list))
+
+(defun -max-by (comparator list)
+  "Take a comparison function COMPARATOR and a LIST and return
+the greatest element of the list by the comparison function.
+
+See also combinator `-on' which can transform the values before
+comparing them."
+  (--reduce (if (funcall comparator it acc) it acc) list))
+
+(defun -min-by (comparator list)
+  "Take a comparison function COMPARATOR and a LIST and return
+the least element of the list by the comparison function.
+
+See also combinator `-on' which can transform the values before
+comparing them."
+  (--reduce (if (funcall comparator it acc) acc it) list))
+
+(defmacro --max-by (form list)
+  "Anaphoric version of `-max-by'.
+
+The items for the comparator form are exposed as \"it\" and \"other\"."
+  (declare (debug (form form)))
+  `(-max-by (lambda (it other) ,form) ,list))
+
+(defmacro --min-by (form list)
+  "Anaphoric version of `-min-by'.
+
+The items for the comparator form are exposed as \"it\" and \"other\"."
+  (declare (debug (form form)))
+  `(-min-by (lambda (it other) ,form) ,list))
+
+(defun -iterate (fun init n)
+  "Return a list of iterated applications of FUN to INIT.
+
+This means a list of form:
+
+  (init (fun init) (fun (fun init)) ...)
+
+N is the length of the returned list."
+  (if (= n 0) nil
+    (let ((r (list init)))
+      (--dotimes (1- n)
+        (push (funcall fun (car r)) r))
+      (nreverse r))))
+
+(defun -fix (fn list)
+  "Compute the (least) fixpoint of FN with initial input LIST.
+
+FN is called at least once, results are compared with `equal'."
+  (let ((re (funcall fn list)))
+    (while (not (equal list re))
+      (setq list re)
+      (setq re (funcall fn re)))
+    re))
+
+(defmacro --fix (form list)
+  "Anaphoric form of `-fix'."
+  `(-fix (lambda (it) ,form) ,list))
+
+(defun -unfold (fun seed)
+  "Build a list from SEED using FUN.
+
+This is \"dual\" operation to `-reduce-r': while -reduce-r
+consumes a list to produce a single value, `-unfold' takes a
+seed value and builds a (potentially infinite!) list.
+
+FUN should return `nil' to stop the generating process, or a
+cons (A . B), where A will be prepended to the result and B is
+the new seed."
+  (let ((last (funcall fun seed)) r)
+    (while last
+      (push (car last) r)
+      (setq last (funcall fun (cdr last))))
+    (nreverse r)))
+
+(defmacro --unfold (form seed)
+  "Anaphoric version of `-unfold'."
+  (declare (debug (form form)))
+  `(-unfold (lambda (it) ,form) ,seed))
+
+(defun -cons-pair? (con)
+  "Return non-nil if CON is true cons pair.
+That is (A . B) where B is not a list."
+  (and (listp con)
+       (not (listp (cdr con)))))
+
+(defun -cons-to-list (con)
+  "Convert a cons pair to a list with `car' and `cdr' of the pair respectively."
+  (list (car con) (cdr con)))
+
+(defun -value-to-list (val)
+  "Convert a value to a list.
+
+If the value is a cons pair, make a list with two elements, `car'
+and `cdr' of the pair respectively.
+
+If the value is anything else, wrap it in a list."
+  (cond
+   ((-cons-pair? val) (-cons-to-list val))
+   (t (list val))))
+
+(defun -tree-mapreduce-from (fn folder init-value tree)
+  "Apply FN to each element of TREE, and make a list of the results.
+If elements of TREE are lists themselves, apply FN recursively to
+elements of these nested lists.
+
+Then reduce the resulting lists using FOLDER and initial value
+INIT-VALUE. See `-reduce-r-from'.
+
+This is the same as calling `-tree-reduce-from' after `-tree-map'
+but is twice as fast as it only traverse the structure once."
+  (cond
+   ((not tree) nil)
+   ((-cons-pair? tree) (funcall fn tree))
+   ((listp tree)
+    (-reduce-r-from folder init-value (mapcar (lambda (x) (-tree-mapreduce-from fn folder init-value x)) tree)))
+   (t (funcall fn tree))))
+
+(defmacro --tree-mapreduce-from (form folder init-value tree)
+  "Anaphoric form of `-tree-mapreduce-from'."
+  (declare (debug (form form form form)))
+  `(-tree-mapreduce-from (lambda (it) ,form) (lambda (it acc) ,folder) ,init-value ,tree))
+
+(defun -tree-mapreduce (fn folder tree)
+  "Apply FN to each element of TREE, and make a list of the results.
+If elements of TREE are lists themselves, apply FN recursively to
+elements of these nested lists.
+
+Then reduce the resulting lists using FOLDER and initial value
+INIT-VALUE. See `-reduce-r-from'.
+
+This is the same as calling `-tree-reduce' after `-tree-map'
+but is twice as fast as it only traverse the structure once."
+  (cond
+   ((not tree) nil)
+   ((-cons-pair? tree) (funcall fn tree))
+   ((listp tree)
+    (-reduce-r folder (mapcar (lambda (x) (-tree-mapreduce fn folder x)) tree)))
+   (t (funcall fn tree))))
+
+(defmacro --tree-mapreduce (form folder tree)
+  "Anaphoric form of `-tree-mapreduce'."
+  (declare (debug (form form form)))
+  `(-tree-mapreduce (lambda (it) ,form) (lambda (it acc) ,folder) ,tree))
+
+(defun -tree-map (fn tree)
+  "Apply FN to each element of TREE while preserving the tree structure."
+  (cond
+   ((not tree) nil)
+   ((-cons-pair? tree) (funcall fn tree))
+   ((listp tree)
+    (mapcar (lambda (x) (-tree-map fn x)) tree))
+   (t (funcall fn tree))))
+
+(defmacro --tree-map (form tree)
+  "Anaphoric form of `-tree-map'."
+  (declare (debug (form form)))
+  `(-tree-map (lambda (it) ,form) ,tree))
+
+(defun -tree-reduce-from (fn init-value tree)
+  "Use FN to reduce elements of list TREE.
+If elements of TREE are lists themselves, apply the reduction recursively.
+
+FN is first applied to INIT-VALUE and first element of the list,
+then on this result and second element from the list etc.
+
+The initial value is ignored on cons pairs as they always contain
+two elements."
+  (cond
+   ((not tree) nil)
+   ((-cons-pair? tree) tree)
+   ((listp tree)
+    (-reduce-r-from fn init-value (mapcar (lambda (x) (-tree-reduce-from fn init-value x)) tree)))
+   (t tree)))
+
+(defmacro --tree-reduce-from (form init-value tree)
+  "Anaphoric form of `-tree-reduce-from'."
+  (declare (debug (form form form)))
+  `(-tree-reduce-from (lambda (it acc) ,form) ,init-value ,tree))
+
+(defun -tree-reduce (fn tree)
+  "Use FN to reduce elements of list TREE.
+If elements of TREE are lists themselves, apply the reduction recursively.
+
+FN is first applied to first element of the list and second
+element, then on this result and third element from the list etc.
+
+See `-reduce-r' for how exactly are lists of zero or one element handled."
+  (cond
+   ((not tree) nil)
+   ((-cons-pair? tree) tree)
+   ((listp tree)
+    (-reduce-r fn (mapcar (lambda (x) (-tree-reduce fn x)) tree)))
+   (t tree)))
+
+(defmacro --tree-reduce (form tree)
+  "Anaphoric form of `-tree-reduce'."
+  (declare (debug (form form)))
+  `(-tree-reduce (lambda (it acc) ,form) ,tree))
+
+(defun -tree-map-nodes (pred fun tree)
+  "Call FUN on each node of TREE that satisfies PRED.
+
+If PRED returns nil, continue descending down this node.  If PRED
+returns non-nil, apply FUN to this node and do not descend
+further."
+  (if (funcall pred tree)
+      (funcall fun tree)
+    (if (and (listp tree)
+             (not (-cons-pair? tree)))
+        (-map (lambda (x) (-tree-map-nodes pred fun x)) tree)
+      tree)))
+
+(defmacro --tree-map-nodes (pred form tree)
+  "Anaphoric form of `-tree-map-nodes'."
+  `(-tree-map-nodes (lambda (it) ,pred) (lambda (it) ,form) ,tree))
+
+(defun -tree-seq (branch children tree)
+  "Return a sequence of the nodes in TREE, in depth-first search order.
+
+BRANCH is a predicate of one argument that returns non-nil if the
+passed argument is a branch, that is, a node that can have children.
+
+CHILDREN is a function of one argument that returns the children
+of the passed branch node.
+
+Non-branch nodes are simply copied."
+  (cons tree
+        (when (funcall branch tree)
+          (-mapcat (lambda (x) (-tree-seq branch children x))
+                   (funcall children tree)))))
+
+(defmacro --tree-seq (branch children tree)
+  "Anaphoric form of `-tree-seq'."
+  `(-tree-seq (lambda (it) ,branch) (lambda (it) ,children) ,tree))
+
+(defun -clone (list)
+  "Create a deep copy of LIST.
+The new list has the same elements and structure but all cons are
+replaced with new ones.  This is useful when you need to clone a
+structure such as plist or alist."
+  (-tree-map 'identity list))
+
+(defun dash-enable-font-lock ()
+  "Add syntax highlighting to dash functions, macros and magic values."
+  (eval-after-load "lisp-mode"
+    '(progn
+       (let ((new-keywords '(
+                             "-each"
+                             "--each"
+                             "-each-while"
+                             "--each-while"
+                             "-dotimes"
+                             "--dotimes"
+                             "-map"
+                             "--map"
+                             "-reduce-from"
+                             "--reduce-from"
+                             "-reduce"
+                             "--reduce"
+                             "-reduce-r-from"
+                             "--reduce-r-from"
+                             "-reduce-r"
+                             "--reduce-r"
+                             "-filter"
+                             "--filter"
+                             "-select"
+                             "--select"
+                             "-remove"
+                             "--remove"
+                             "-reject"
+                             "--reject"
+                             "-remove-first"
+                             "--remove-first"
+                             "-reject-first"
+                             "--reject-first"
+                             "-remove-last"
+                             "--remove-last"
+                             "-reject-last"
+                             "--reject-last"
+                             "-remove-item"
+                             "-non-nil"
+                             "-keep"
+                             "--keep"
+                             "-map-indexed"
+                             "--map-indexed"
+                             "-splice"
+                             "--splice"
+                             "-splice-list"
+                             "--splice-list"
+                             "-map-when"
+                             "--map-when"
+                             "-replace-where"
+                             "--replace-where"
+                             "-map-first"
+                             "--map-first"
+                             "-map-last"
+                             "--map-last"
+                             "-replace"
+                             "-replace-first"
+                             "-replace-last"
+                             "-flatten"
+                             "-flatten-n"
+                             "-concat"
+                             "-mapcat"
+                             "--mapcat"
+                             "-copy"
+                             "-cons*"
+                             "-snoc"
+                             "-first"
+                             "--first"
+                             "-find"
+                             "--find"
+                             "-some"
+                             "--some"
+                             "-any"
+                             "--any"
+                             "-last"
+                             "--last"
+                             "-first-item"
+                             "-last-item"
+                             "-butlast"
+                             "-count"
+                             "--count"
+                             "-any?"
+                             "--any?"
+                             "-some?"
+                             "--some?"
+                             "-any-p"
+                             "--any-p"
+                             "-some-p"
+                             "--some-p"
+                             "-all?"
+                             "--all?"
+                             "-every?"
+                             "--every?"
+                             "-all-p"
+                             "--all-p"
+                             "-every-p"
+                             "--every-p"
+                             "-none?"
+                             "--none?"
+                             "-none-p"
+                             "--none-p"
+                             "-only-some?"
+                             "--only-some?"
+                             "-only-some-p"
+                             "--only-some-p"
+                             "-slice"
+                             "-take"
+                             "-drop"
+                             "-take-while"
+                             "--take-while"
+                             "-drop-while"
+                             "--drop-while"
+                             "-split-at"
+                             "-rotate"
+                             "-insert-at"
+                             "-replace-at"
+                             "-update-at"
+                             "--update-at"
+                             "-remove-at"
+                             "-remove-at-indices"
+                             "-split-with"
+                             "--split-with"
+                             "-split-on"
+                             "-split-when"
+                             "--split-when"
+                             "-separate"
+                             "--separate"
+                             "-partition-all-in-steps"
+                             "-partition-in-steps"
+                             "-partition-all"
+                             "-partition"
+                             "-partition-by"
+                             "--partition-by"
+                             "-partition-by-header"
+                             "--partition-by-header"
+                             "-group-by"
+                             "--group-by"
+                             "-interpose"
+                             "-interleave"
+                             "-zip-with"
+                             "--zip-with"
+                             "-zip"
+                             "-zip-fill"
+                             "-cycle"
+                             "-pad"
+                             "-annotate"
+                             "--annotate"
+                             "-table"
+                             "-table-flat"
+                             "-partial"
+                             "-elem-index"
+                             "-elem-indices"
+                             "-find-indices"
+                             "--find-indices"
+                             "-find-index"
+                             "--find-index"
+                             "-find-last-index"
+                             "--find-last-index"
+                             "-select-by-indices"
+                             "-grade-up"
+                             "-grade-down"
+                             "->"
+                             "->>"
+                             "-->"
+                             "-when-let"
+                             "-when-let*"
+                             "--when-let"
+                             "-if-let"
+                             "-if-let*"
+                             "--if-let"
+                             "-let*"
+                             "-let"
+                             "-lambda"
+                             "-distinct"
+                             "-uniq"
+                             "-union"
+                             "-intersection"
+                             "-difference"
+                             "-contains?"
+                             "-contains-p"
+                             "-same-items?"
+                             "-same-items-p"
+                             "-is-prefix-p"
+                             "-is-prefix?"
+                             "-is-suffix-p"
+                             "-is-suffix?"
+                             "-is-infix-p"
+                             "-is-infix?"
+                             "-sort"
+                             "--sort"
+                             "-list"
+                             "-repeat"
+                             "-sum"
+                             "-product"
+                             "-max"
+                             "-min"
+                             "-max-by"
+                             "--max-by"
+                             "-min-by"
+                             "--min-by"
+                             "-iterate"
+                             "--iterate"
+                             "-fix"
+                             "--fix"
+                             "-unfold"
+                             "--unfold"
+                             "-cons-pair?"
+                             "-cons-to-list"
+                             "-value-to-list"
+                             "-tree-mapreduce-from"
+                             "--tree-mapreduce-from"
+                             "-tree-mapreduce"
+                             "--tree-mapreduce"
+                             "-tree-map"
+                             "--tree-map"
+                             "-tree-reduce-from"
+                             "--tree-reduce-from"
+                             "-tree-reduce"
+                             "--tree-reduce"
+                             "-tree-seq"
+                             "--tree-seq"
+                             "-tree-map-nodes"
+                             "--tree-map-nodes"
+                             "-clone"
+                             "-rpartial"
+                             "-juxt"
+                             "-applify"
+                             "-on"
+                             "-flip"
+                             "-const"
+                             "-cut"
+                             "-orfn"
+                             "-andfn"
+                             "-iteratefn"
+                             "-fixfn"
+                             "-prodfn"
+                             ))
+             (special-variables '(
+                                  "it"
+                                  "it-index"
+                                  "acc"
+                                  "other"
+                                  )))
+         (font-lock-add-keywords 'emacs-lisp-mode `((,(concat "\\_<" (regexp-opt special-variables 'paren) "\\_>")
+                                                     1 font-lock-variable-name-face)) 'append)
+         (font-lock-add-keywords 'emacs-lisp-mode `((,(concat "(\\s-*" (regexp-opt new-keywords 'paren) "\\_>")
+                                                     1 font-lock-keyword-face)) 'append))
+       (--each (buffer-list)
+         (with-current-buffer it
+           (when (and (eq major-mode 'emacs-lisp-mode)
+                      (boundp 'font-lock-mode)
+                      font-lock-mode)
+             (font-lock-refresh-defaults)))))))
+
+(provide 'dash)
+;;; dash.el ends here
diff --git a/tests/compat/shut-up.el b/tests/compat/shut-up.el
new file mode 100644
index 000000000..d6c5ec74f
--- /dev/null
+++ b/tests/compat/shut-up.el
@@ -0,0 +1,148 @@
+;;; shut-up.el --- Shut up would you!  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2013, 2014 Johan Andersson
+;; Copyright (C) 2014, 2015 Sebastian Wiesner <swiesner@lunaryorn.com>
+
+;; Author: Johan Andersson <johan.rejeep@gmail.com>
+;; Maintainer: Johan Andersson <johan.rejeep@gmail.com>
+;; Package-Requires: ((cl-lib "0.3") (emacs "24"))
+;; Version: 0.3.2
+;; URL: http://github.com/rejeep/shut-up.el
+
+;; This file is NOT part of GNU Emacs.
+
+;;; License:
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'cl-lib)
+(eval-when-compile
+  (defvar dired-use-ls-dired))
+
+;; NOTE: This variable has been added in most recent version of
+;; Emacs. It's declared here to support lexical binding and to avoid
+;; compiler warnings.
+(defvar inhibit-message nil)
+
+(defvar shut-up-ignore nil
+  "When non-nil, do not hide output inside `shut-up'.
+
+Changes to this variable inside a `shut-up' block has no
+effect.")
+
+;; Preserve the original definition of `write-region'
+(fset 'shut-up-write-region-original (symbol-function 'write-region))
+
+(defun shut-up-write-region (start end filename
+                                   &optional append visit lockname mustbenew)
+  "Like `write-region', but try to suppress any messages."
+  (unless visit
+    (setq visit 'no-message))
+  ;; Call our "copy" of `write-region', because if this function is used to
+  ;; override `write-region', calling `write-region' directly here would result
+  ;; in any endless recursion.
+  (shut-up-write-region-original start end filename
+                                 append visit lockname mustbenew))
+
+
+(fset 'shut-up-load-original (symbol-function 'load))
+
+(defun shut-up-load (file &optional noerror _nomessage nosuffix must-suffix)
+  "Like `load', but try to be quiet about it."
+  (shut-up-load-original file noerror :nomessage nosuffix must-suffix))
+
+(defun shut-up-buffer-string (buffer)
+  "Get the contents of BUFFER.
+
+When BUFFER is alive, return its contents without properties.
+Otherwise return nil."
+  (when (buffer-live-p buffer)
+    (with-current-buffer buffer
+      (buffer-substring-no-properties (point-min) (point-max)))))
+
+(defun shut-up-insert-to-buffer (object buffer)
+  "Insert OBJECT into BUFFER.
+
+If BUFFER is not live, do nothing."
+  (when (buffer-live-p buffer)
+    (with-current-buffer buffer
+      (cl-typecase object
+        (character (insert-char object 1))
+        (string (insert object))
+        (t (princ object #'insert-char))))))
+
+;;;###autoload
+(defmacro shut-up (&rest body)
+  "Evaluate BODY with silenced output.
+
+While BODY is evaluated, all output is redirected to a buffer,
+unless `shut-up-ignore' is non-nil.  This affects:
+
+- `message'
+- All functions using `standard-output' (e.g. `print', `princ', etc.)
+
+Inside BODY, the buffer is bound to the lexical variable
+`shut-up-sink'.  Additionally provide a lexical function
+`shut-up-current-output', which returns the current contents of
+`shut-up-sink' when called with no arguments.
+
+Changes to the variable `shut-up-ignore' inside BODY does not
+have any affect."
+  (declare (indent 0))
+  `(let ((shut-up-sink (generate-new-buffer " *shutup*"))
+         (inhibit-message t))
+    (cl-labels ((shut-up-current-output () (or (shut-up-buffer-string shut-up-sink) "")))
+      (if shut-up-ignore
+          (progn ,@body)
+        (unwind-protect
+            ;; Override `standard-output', for `print' and friends, and
+            ;; monkey-patch `message'
+            (cl-letf ((standard-output
+                       (lambda (char)
+                         (shut-up-insert-to-buffer char shut-up-sink)))
+                      ((symbol-function 'message)
+                       (lambda (fmt &rest args)
+                         (when fmt
+                           (let ((text (concat (apply #'format fmt args) "\n")))
+                            (shut-up-insert-to-buffer text shut-up-sink)))))
+                      ((symbol-function 'write-region) #'shut-up-write-region)
+                      ((symbol-function 'load) #'shut-up-load))
+              ,@body)
+          (and (buffer-name shut-up-sink)
+               (kill-buffer shut-up-sink)))))))
+
+;;;###autoload
+(defun shut-up-silence-emacs ()
+  "Silence Emacs.
+
+Change Emacs settings to reduce the output.
+
+WARNING: This function has GLOBAL SIDE-EFFECTS.  You should only
+call this function in `noninteractive' sessions."
+  ;; Loading vc-git...
+  (remove-hook 'find-file-hooks 'vc-find-file-hook)
+
+  ;; ls does not support --dired; see `dired-use-ls-dired' for more details.
+  (eval-after-load "dired"
+    '(setq dired-use-ls-dired nil)))
+
+(provide 'shut-up)
+
+;;; shut-up.el ends here
diff --git a/tests/compat/undercover.el b/tests/compat/undercover.el
new file mode 100644
index 000000000..18a7c6296
--- /dev/null
+++ b/tests/compat/undercover.el
@@ -0,0 +1,455 @@
+;;; undercover.el --- Test coverage library for Emacs -*- lexical-binding: t -*-
+
+;; Copyright (c) 2014 Sviridov Alexander
+
+;; Author: Sviridov Alexander <sviridov.vmi@gmail.com>
+;; URL: https://github.com/sviridov/undercover.el
+;; Created: Sat Sep 27 2014
+;; Keywords: lisp, tests, coverage, tools
+;; Version: 0.5.0
+;; Package-Requires: ((emacs "24") (dash "2.0.0") (shut-up "0.3.2"))
+
+;;; Commentary:
+
+;; Provides a test coverage tools for Emacs packages.
+
+;;; Code:
+
+(eval-when-compile (require 'cl))
+
+(require 'edebug)
+(require 'json)
+(require 'dash)
+(require 'shut-up)
+
+(defconst undercover-version "0.5.0")
+
+(defvar undercover-force-coverage nil
+  "If nil, test coverage check will be done only under continuous integration service.")
+
+(defvar undercover--send-report t
+  "If not nil, test coverage report will be sent to coveralls.io.")
+
+(defvar undercover--report-file-path "/tmp/undercover_coveralls_report"
+  "Path to save coveralls.io report.")
+
+(defvar undercover--files nil
+  "List of files for test coverage check.")
+
+(defvar undercover--files-coverage-statistics (make-hash-table :test 'equal)
+  "Table of coverage statistics for each file in `undercover--files'.")
+
+(defvar undercover--old-edebug-make-form-wrapper
+  (symbol-function 'edebug-make-form-wrapper))
+
+;; Utilities
+
+(defun undercover--fill-hash-table (hash-table &rest keys-and-values)
+  "Fill HASH-TABLE from KEYS-AND-VALUES."
+  (loop for (key value) on keys-and-values by #'cddr
+        do (puthash key value hash-table))
+  hash-table)
+
+(defun undercover--make-hash-table (&rest keys-and-values)
+  "Create new hash-table and fill it from KEYS-AND-VALUES."
+  (apply #'undercover--fill-hash-table (make-hash-table :test 'equal) keys-and-values))
+
+(defun undercover--wildcards-to-files (wildcards)
+  "Return list of files matched by WILDCARDS.
+Example of WILDCARDS: (\"*.el\" \"subdir/*.el\" (:exclude \"exclude-*.el\"))."
+  (destructuring-bind (exclude-clauses include-wildcards)
+      (--separate (and (consp it) (eq :exclude (car it))) wildcards)
+    (let* ((exclude-wildcards (-mapcat #'cdr exclude-clauses))
+           (exclude-files (-mapcat #'file-expand-wildcards exclude-wildcards))
+           (include-files (-mapcat #'file-expand-wildcards include-wildcards)))
+      (-difference include-files exclude-files))))
+
+;; `edebug' related functions and hacks:
+
+;; http://debbugs.gnu.org/cgi/bugreport.cgi?bug=6415
+(def-edebug-spec cl-destructuring-bind (sexp form body))
+(def-edebug-spec destructuring-bind (sexp form body))
+
+(def-edebug-spec cl-symbol-macrolet ((&rest (symbolp sexp)) cl-declarations body))
+(def-edebug-spec symbol-macrolet ((&rest (symbolp sexp)) cl-declarations body))
+
+(def-edebug-spec cl-type-spec sexp)
+
+(def-edebug-spec when-let ([&or (symbolp form) (&rest (symbolp form))] body))
+
+(defun undercover--fallback-file-handler (operation args)
+  "Handle any file OPERATION with ARGS."
+  (let ((inhibit-file-name-handlers
+         (cons 'undercover-file-handler
+               (and (eq inhibit-file-name-operation operation)
+                    inhibit-file-name-handlers)))
+        (inhibit-file-name-operation operation))
+    (apply operation args)))
+
+(defun undercover--load-file-handler (file)
+  "Handle `load' FILE operation."
+  (let ((edebug-all-defs (undercover--coverage-enabled-p))
+        (load-file-name (file-truename file))
+        (load-in-progress t))
+    (unwind-protect
+        (progn
+          (save-excursion (eval-buffer (find-file load-file-name)))
+          (push load-file-name undercover--files))
+      (switch-to-buffer (current-buffer)))))
+
+(defun undercover--show-load-file-error (filename)
+  (message "UNDERCOVER: error while covering %s" filename)
+  (message "UNDERCOVER: please open a new issue at https://github.com/sviridov/undercover.el/issues"))
+
+(defun undercover-file-handler (operation &rest args)
+  "Handle `load' OPERATION.  Ignore all ARGS except first."
+  (if (eq 'load operation)
+      (condition-case nil
+          (undercover--load-file-handler (car args))
+        (error
+         (undercover--show-load-file-error (car args))
+         (undercover--fallback-file-handler operation args)))
+    (undercover--fallback-file-handler operation args)))
+
+(defun undercover--edebug-files (files)
+  "Use `edebug' package to instrument all macros and functions in FILES."
+  (when files
+    (let ((regexp (->> files (regexp-opt) (format "/%s$"))))
+      (add-to-list 'file-name-handler-alist (cons regexp 'undercover-file-handler)))))
+
+(setf (symbol-function 'undercover--stop-point-before)
+      (lambda (before-index)
+        "Increase number of times that stop point at BEFORE-INDEX was covered."
+        (when (boundp 'edebug-freq-count)
+          (incf (aref edebug-freq-count before-index)))
+        before-index))
+
+(setf (symbol-function 'undercover--stop-point-after)
+      (cons 'macro
+        (lambda (before-index after-index form)
+          "Increase number of times that stop point at AFTER-INDEX was covered."
+         `(let ((before-index ,before-index)
+                (after-index ,after-index))
+            (unwind-protect ,form
+              (when (boundp 'edebug-freq-count)
+                (aset edebug-freq-count after-index (+ 1 (aref edebug-freq-count after-index)))
+                (undercover--align-counts-between-stop-points before-index after-index)))))))
+
+(setf (symbol-function 'undercover--align-counts-between-stop-points)
+      (lambda (before-index after-index)
+        "Decrease number of times that stop points between BEFORE-INDEX and AFTER-INDEX are covered."
+        (do ((index (1+ before-index) (1+ index)))
+            ((>= index after-index))
+          (setf (aref edebug-freq-count index)
+                (min (aref edebug-freq-count index)
+                     (aref edebug-freq-count before-index))))))
+
+(defun undercover--stop-points (name)
+  "Return stop points ordered by position for NAME."
+  (append (nth 2 (get name 'edebug)) nil))
+
+(defun undercover--stop-points-covers (name)
+  "Return number of covers for each stop point ordered by position for NAME."
+  (append (get name 'edebug-freq-count) nil))
+
+(defun undercover--shut-up-edebug-message ()
+  "Muffle `edebug' message \"EDEBUG: function\"."
+  ;; HACK: I don't use `defadvice' because of cryptic error with `shut-up-sink'.
+  ;; https://travis-ci.org/sviridov/multiple-cursors.el/builds/37529750#L1387
+  ;; https://travis-ci.org/sviridov/expand-region.el/builds/37576813#L285
+  (setf (symbol-function 'edebug-make-form-wrapper)
+        (lambda (&rest args)
+          (shut-up (apply undercover--old-edebug-make-form-wrapper args)))))
+
+(defun undercover--set-edebug-handlers ()
+  "Replace and advice some `edebug' functions with `undercover' handlers."
+  (defalias 'edebug-before 'undercover--stop-point-before)
+  (defalias 'edebug-after 'undercover--stop-point-after)
+  (undercover--shut-up-edebug-message)
+  ;; HACK: Ensures that debugger is turned off.
+  ;; https://travis-ci.org/sviridov/multiple-cursors.el/builds/37672312#L350
+  ;; https://travis-ci.org/sviridov/expand-region.el/builds/37577423#L336
+  (setq debug-on-error  nil
+        debug-on-signal nil
+        edebug-on-error nil))
+
+;; Coverage statistics related functions:
+
+(defun undercover--symbol-coverage-statistics (edebug-symbol statistics)
+  "Collect coverage statistics for EDEBUG-SYMBOL into STATISTICS hash."
+  (let* ((start-marker (car (get edebug-symbol 'edebug)))
+         (points (undercover--stop-points edebug-symbol))
+         (points-covers (undercover--stop-points-covers edebug-symbol))
+         (points-and-covers (map 'list #'cons points points-covers)))
+    (dolist (point-and-cover points-and-covers)
+      (let* ((point (car point-and-cover))
+             (line  (line-number-at-pos (+ point start-marker)))
+             (cover (cdr point-and-cover))
+             (previous-score (gethash line statistics cover))
+             (new-score (min previous-score cover)))
+        (puthash line new-score statistics)))))
+
+(defun undercover--file-coverage-statistics ()
+  "Collect coverage statistics for current-file into hash.
+Keys of that hash are line numbers.
+Values of that hash are number of covers."
+  (let ((statistics (make-hash-table)))
+    (dolist (edebug-data edebug-form-data)
+      (let ((edebug-symbol (car edebug-data)))
+        (when (get edebug-symbol 'edebug)
+          (undercover--symbol-coverage-statistics edebug-symbol statistics))))
+    statistics))
+
+(defun undercover--collect-file-coverage (file)
+  "Collect coverage statistics for FILE."
+  (save-excursion
+    (find-file file)
+    (if edebug-form-data
+        (undercover--fill-hash-table undercover--files-coverage-statistics
+          file (undercover--file-coverage-statistics))
+      (setq undercover--files (delq file undercover--files)))))
+
+(defun undercover--collect-files-coverage (files)
+  "Collect coverage statistics for each file in FILES."
+  (dolist (file files)
+    (undercover--collect-file-coverage file)))
+
+;; Continuous integration related functions:
+
+(defun undercover--under-travic-ci-p ()
+  "Check that `undercover' running under Travis CI service."
+  (getenv "TRAVIS"))
+
+(defun undercover--coveralls-repo-token ()
+  "Return coveralls.io repo token provided by user."
+  (getenv "COVERALLS_REPO_TOKEN"))
+
+(defun undercover--under-ci-p ()
+  "Check that `undercover' running under continuous integration service."
+  (or (undercover--coveralls-repo-token) (undercover--under-travic-ci-p)))
+
+;;; Reports related functions:
+
+(defun undercover--determine-report-type ()
+  "Automatic report-type determination."
+  (and (undercover--under-ci-p) 'coveralls))
+
+(defun undercover--get-git-info (&rest args)
+  "Execute Git with ARGS, returning the first line of its output."
+  (with-temp-buffer
+    (apply #'process-file "git" nil t nil "--no-pager" args)
+    (goto-char (point-min))
+    (buffer-substring-no-properties
+     (line-beginning-position)
+     (line-end-position))))
+
+(defun undercover--get-git-info-from-log (format)
+  "Get first line of Git log in given FORMAT."
+  (undercover--get-git-info "log" "-1" (format "--pretty=format:%%%s" format)))
+
+(defun undercover--get-git-remotes ()
+  "Return list of Git remotes."
+  (with-temp-buffer
+    (process-file "git" nil t nil "--no-pager" "remote")
+    (let ((remotes (split-string (buffer-string) "\n" t))
+          (config-path-format (format "remote.%%s.url"))
+          (remotes-info nil))
+      (dolist (remote remotes remotes-info)
+        (let* ((remote-url (undercover--get-git-info "config" (format config-path-format remote)))
+               (remote-table (undercover--make-hash-table
+                              "name" remote
+                              "url"  remote-url)))
+          (push remote-table remotes-info))))))
+
+;; coveralls.io report:
+
+(defun undercover--update-coveralls-report-with-repo-token (report)
+  "Update test coverage REPORT for coveralls.io with repository token."
+  (puthash "repo_token" (undercover--coveralls-repo-token) report))
+
+(defun undercover--try-update-coveralls-report-with-shippable (report)
+  "Update test coverage REPORT for coveralls.io with Shippable service information."
+  (when (getenv "SHIPPABLE")
+    (undercover--fill-hash-table report
+      "service_name"   "shippable"
+      "service_job_id" (getenv "BUILD_NUMBER"))
+    (unless (string-equal "false" (getenv "PULL_REQUEST"))
+      (undercover--fill-hash-table report
+        "service_pull_request" (getenv "PULL_REQUEST")))))
+
+(defun undercover--update-coveralls-report-with-travis-ci (report)
+  "Update test coverage REPORT for coveralls.io with Travis CI service information."
+  (undercover--fill-hash-table report
+    "service_name"   "travis-ci"
+    "service_job_id" (getenv "TRAVIS_JOB_ID")))
+
+(defun undercover--update-coveralls-report-with-git (report)
+  "Update test coverage REPORT for coveralls.io with Git information."
+  (undercover--fill-hash-table report
+    "git" (undercover--make-hash-table
+           "branch"  (undercover--get-git-info "rev-parse" "--abbrev-ref" "HEAD")
+           "remotes" (undercover--get-git-remotes)
+           "head"    (undercover--make-hash-table
+                      "id"              (undercover--get-git-info-from-log "H")
+                      "author_name"     (undercover--get-git-info-from-log "aN")
+                      "author_email"    (undercover--get-git-info-from-log "ae")
+                      "committer_name"  (undercover--get-git-info-from-log "cN")
+                      "committer_email" (undercover--get-git-info-from-log "ce")
+                      "message"         (undercover--get-git-info-from-log "s")))))
+
+(defun undercover--coveralls-file-coverage-report (statistics)
+  "Translate file coverage STATISTICS into coveralls.io format."
+  (let (file-coverage)
+    (dotimes (line (count-lines (point-min) (point-max)))
+      (push (gethash (1+ line) statistics) file-coverage))
+    (nreverse file-coverage)))
+
+(defun undercover--coveralls-file-report (file)
+  "Create part of coveralls.io report for FILE."
+  (save-excursion
+    (find-file file)
+    (let ((file-name (file-relative-name file (locate-dominating-file default-directory ".git")))
+          (file-content (buffer-substring-no-properties (point-min) (point-max)))
+          (coverage-report (undercover--coveralls-file-coverage-report
+                            (gethash file undercover--files-coverage-statistics))))
+      (undercover--make-hash-table
+       "name"     file-name
+       "source"   file-content
+       "coverage" coverage-report))))
+
+(defun undercover--fill-coveralls-report (report)
+  "Fill test coverage REPORT for coveralls.io."
+  (undercover--fill-hash-table report
+    "source_files" (mapcar #'undercover--coveralls-file-report undercover--files)))
+
+(defun undercover--merge-coveralls-report-file-lines-coverage (old-coverage new-coverage)
+  "Merge test coverage for lines from OLD-COVERAGE and NEW-COVERAGE."
+  (loop for (old-line-coverage . new-line-coverage)
+        in (-zip-fill 0 old-coverage new-coverage)
+        collect (cond
+                 ((null old-line-coverage) new-line-coverage)
+                 ((null new-line-coverage) old-line-coverage)
+                 (t (+ new-line-coverage old-line-coverage)))))
+
+(defun undercover--merge-coveralls-report-file-coverage (old-file-hash source-files-report)
+  "Merge test coverage from OLD-FILE-HASH into SOURCE-FILES-REPORT."
+  (let* ((file-name (gethash "name" old-file-hash))
+         (old-coverage (gethash "coverage" old-file-hash))
+         (new-file-hash (--first (string-equal file-name (gethash "name" it))
+                                 source-files-report)))
+    (if new-file-hash
+        (undercover--fill-hash-table new-file-hash
+          "coverage" (undercover--merge-coveralls-report-file-lines-coverage
+                      old-coverage (gethash "coverage" new-file-hash)))
+      (rplacd (last source-files-report)
+              (cons old-file-hash nil)))))
+
+(defun undercover--merge-coveralls-reports (report)
+  "Merge test coverage REPORT with existing from `undercover--report-file-path'."
+  (ignore-errors
+    (let* ((json-object-type 'hash-table)
+           (json-array-type 'list)
+           (old-report (json-read-file undercover--report-file-path))
+           (new-source-files-report (gethash "source_files" report)))
+      (dolist (old-file-hash (gethash "source_files" old-report))
+        (undercover--merge-coveralls-report-file-coverage
+         old-file-hash new-source-files-report)))))
+
+(defun undercover--create-coveralls-report ()
+  "Create test coverage report for coveralls.io."
+  (undercover--collect-files-coverage undercover--files)
+  (let ((report (make-hash-table :test 'equal)))
+    (cond
+     ((undercover--coveralls-repo-token)
+      (undercover--update-coveralls-report-with-repo-token report)
+      (undercover--try-update-coveralls-report-with-shippable report))
+     ((undercover--under-travic-ci-p) (undercover--update-coveralls-report-with-travis-ci report))
+     (t (error "Unsupported coveralls.io report")))
+    (undercover--update-coveralls-report-with-git report)
+    (undercover--fill-coveralls-report report)
+    (undercover--merge-coveralls-reports report)
+    (json-encode report)))
+
+(defun undercover--save-coveralls-report (json-report)
+  "Save JSON-REPORT to `undercover--report-file-path'."
+  (save-excursion
+    (shut-up
+      (find-file undercover--report-file-path)
+      (erase-buffer)
+      (insert json-report)
+      (save-buffer))))
+
+(defun undercover--send-coveralls-report ()
+  "Send report to coveralls.io."
+  (let ((coveralls-url "https://coveralls.io/api/v1/jobs"))
+    (message "Sending: report to coveralls.io")
+    (shut-up
+     (shell-command
+      (format "curl -v -include --form json_file=@%s %s" undercover--report-file-path coveralls-url)))
+    (message "Sending: OK")))
+
+(defun undercover--coveralls-report ()
+  "Create and submit test coverage report to coveralls.io."
+  (undercover--save-coveralls-report (undercover--create-coveralls-report))
+  (when undercover--send-report
+    (undercover--send-coveralls-report)))
+
+;; `ert-runner' related functions:
+
+(defun undercover-safe-report ()
+  "Version of `undercover-report' that ignore errors."
+  (ignore-errors
+    (undercover-report)))
+
+(defun undercover-report-on-kill ()
+  "Add `undercover-safe-report' to `kill-emacs-hook'."
+  (add-hook 'kill-emacs-hook 'undercover-safe-report))
+
+;;; Main functions:
+
+(defun undercover--coverage-enabled-p ()
+  "Check that `undercover' is enabled."
+  (or undercover-force-coverage (undercover--under-ci-p)))
+
+(defun undercover-report (&optional report-type)
+  "Create and submit (if needed) test coverage report based on REPORT-TYPE.
+Posible values of REPORT-TYPE: coveralls."
+  (when undercover--files
+    (case (or report-type (undercover--determine-report-type))
+      (coveralls (undercover--coveralls-report))
+      (t (error "Unsupported report-type")))))
+
+(defun undercover--set-options (configuration)
+  "Read CONFIGURATION.
+Set `undercover--send-report' and `undercover--report-file-path'.
+Return wildcards."
+  (destructuring-bind (wildcards options)
+      (--separate (or (stringp it) (eq :exclude (car-safe it))) configuration)
+    (dolist (option options wildcards)
+      (case (car-safe option)
+        (:report-file (setq undercover--report-file-path (cadr option)))
+        (:send-report (setq undercover--send-report (cadr option)))
+        (otherwise (error "Unsupported option: %s" option))))))
+
+(defun undercover--setup (configuration)
+  "Enable test coverage for files matched by CONFIGURATION."
+  (when (undercover--coverage-enabled-p)
+    (undercover--set-edebug-handlers)
+    (undercover-report-on-kill)
+    (let ((wildcards (undercover--set-options configuration)))
+      (undercover--edebug-files (undercover--wildcards-to-files wildcards)))))
+
+;;;###autoload
+(defmacro undercover (&rest configuration)
+  "Enable test coverage for files matched by CONFIGURATION.
+Example of CONFIGURATION: (\"*.el\" \"subdir/*.el\" (:exclude \"exclude-*.el\")).
+
+If running under Travic CI automatically generate report
+on `kill-emacs' and send it to coveralls.io."
+  `(undercover--setup
+    (list
+     ,@(--map (if (atom it) it `(list ,@it))
+              configuration))))
+
+(provide 'undercover)
+;;; undercover.el ends here
diff --git a/tests/haskell-indentation-tests.el b/tests/haskell-indentation-tests.el
index d555e8c44..dc2c4c326 100644
--- a/tests/haskell-indentation-tests.el
+++ b/tests/haskell-indentation-tests.el
@@ -746,92 +746,6 @@ function = abc
        xyz"
               (3 0 7))
 
-(hindent-test "45 phrase should not eat whole stack" "
-function =
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-  if True
-  then True
-  else
-"
-              (84 4))
-
 (hindent-test "46 case expression with paths on their own lines" "
 fact n =
   case n of