Adding simple net::url module to parse and format urls.

Author: Daniel Patterson

src/libstd/net.rs

@@ -5,3 +5,6 @@ export tcp;
 
 import ip = net_ip;
 export ip;
+
+import url = net_url;
+export url;

src/libstd/net_url.rs

@@ -0,0 +1,241 @@
+//! Types/fns concerning URLs (see RFC 3986)
+
+import map;
+import map::*;
+
+export url, userinfo, query, from_str, to_str;
+
+type url = {
+    scheme: ~str,
+    user: option<userinfo>,
+    host: ~str,
+    path: ~str,
+    query: query,
+    fragment: option<~str>
+};
+
+type userinfo = {
+    user: ~str,
+    pass: option<~str>
+};
+
+type query = map::hashmap<~str, ~str>;
+
+fn url(-scheme: ~str, -user: option<userinfo>, -host: ~str,
+       -path: ~str, -query: query, -fragment: option<~str>) -> url {
+    { scheme: scheme, user: user, host: host,
+     path: path, query: query, fragment: fragment }
+}
+
+fn userinfo(-user: ~str, -pass: option<~str>) -> userinfo {
+    {user: user, pass: pass}
+}
+
+fn split_char_first(s: ~str, c: char) -> (~str, ~str) {
+    let mut v = str::splitn_char(s, c, 1);
+    if v.len() == 1 {
+        ret (s, ~"");
+    } else {
+        ret (vec::shift(v), vec::pop(v));
+    }
+}
+
+fn userinfo_from_str(uinfo: ~str) -> userinfo {
+    let (user, p) = split_char_first(uinfo, ':');
+    let pass = if str::len(p) == 0 {
+        option::none
+    } else {
+        option::some(p)
+    };
+    ret userinfo(user, pass);
+}
+
+fn userinfo_to_str(-userinfo: userinfo) -> ~str {
+    if option::is_some(userinfo.pass) {
+        ret str::concat(~[copy userinfo.user, ~":",
+                          option::unwrap(copy userinfo.pass),
+                          ~"@"]);
+    } else {
+        ret str::concat(~[copy userinfo.user, ~"@"]);
+    }
+}
+
+fn query_from_str(rawquery: ~str) -> query {
+    let query: query = map::str_hash();
+    if str::len(rawquery) != 0 {
+        for str::split_char(rawquery, '&').each |p| {
+            let (k, v) = split_char_first(p, '=');
+            query.insert(k, v);
+        };
+    }
+    ret query;
+}
+
+fn query_to_str(query: query) -> ~str {
+    let mut strvec = ~[];
+    for query.each |k, v| {
+        strvec += ~[#fmt("%s=%s", k, v)];
+    };
+    ret str::connect(strvec, ~"&");
+}
+
+fn get_scheme(rawurl: ~str) -> option::option<(~str, ~str)> {
+    for str::each_chari(rawurl) |i,c| {
+        if char::is_alphabetic(c) {
+            again;
+        } else if c == ':' && i != 0 {
+            ret option::some((rawurl.slice(0,i),
+                              rawurl.slice(i+3,str::len(rawurl))));
+        } else {
+            ret option::none;
+        }
+    };
+    ret option::none;
+}
+
+/**
+ * Parse a `str` to a `url`
+ *
+ * # Arguments
+ *
+ * `rawurl` - a string representing a full url, including scheme.
+ *
+ * # Returns
+ *
+ * a `url` that contains the parsed representation of the url.
+ *
+ */
+
+fn from_str(rawurl: ~str) -> result::result<url, ~str> {
+    let mut schm = get_scheme(rawurl);
+    if option::is_none(schm) {
+        ret result::err(~"invalid scheme");
+    }
+    let (scheme, rest) = option::unwrap(schm);
+    let (u, rest) = split_char_first(rest, '@');
+    let user = if str::len(rest) == 0 {
+        option::none
+    } else {
+        option::some(userinfo_from_str(u))
+    };
+    let rest = if str::len(rest) == 0 {
+         u
+    } else {
+        rest
+    };
+    let (rest, frag) = split_char_first(rest, '#');
+    let fragment = if str::len(frag) == 0 {
+        option::none
+    } else {
+        option::some(frag)
+    };
+    let (rest, query) = split_char_first(rest, '?');
+    let query = query_from_str(query);
+    let (host, pth) = split_char_first(rest, '/');
+    let mut path = pth;
+    if str::len(path) != 0 {
+        str::unshift_char(path, '/');
+    }
+
+    ret result::ok(url(scheme, user, host, path, query, fragment));
+}
+
+/**
+ * Format a `url` as a string
+ *
+ * # Arguments
+ *
+ * `url` - a url.
+ *
+ * # Returns
+ *
+ * a `str` that contains the formatted url. Note that this will usually
+ * be an inverse of `from_str` but might strip out unneeded separators.
+ * for example, "http://somehost.com?", when parsed and formatted, will
+ * result in just "http://somehost.com".
+ *
+ */
+fn to_str(url: url) -> ~str {
+    let user = if option::is_some(url.user) {
+      userinfo_to_str(option::unwrap(copy url.user))
+    } else {
+       ~""
+    };
+    let query = if url.query.size() == 0 {
+        ~""
+    } else {
+        str::concat(~[~"?", query_to_str(url.query)])
+    };
+    let fragment = if option::is_some(url.fragment) {
+        str::concat(~[~"#", option::unwrap(copy url.fragment)])
+    } else {
+        ~""
+    };
+
+    ret str::concat(~[copy url.scheme,
+                      ~"://",
+                      user,
+                      copy url.host,
+                      copy url.path,
+                      query,
+                      fragment]);
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_full_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org/doc?s=v#something";
+        assert to_str(result::unwrap(from_str(url))) == url;
+    }
+
+    #[test]
+    fn test_userless_url_parse_and_format() {
+        let url = ~"http://rust-lang.org/doc?s=v#something";
+        assert to_str(result::unwrap(from_str(url))) == url;
+    }
+
+    #[test]
+    fn test_queryless_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org/doc#something";
+        assert to_str(result::unwrap(from_str(url))) == url;
+    }
+
+    #[test]
+    fn test_empty_query_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org/doc?#something";
+        let should_be = ~"http://user:pass@rust-lang.org/doc#something";
+        assert to_str(result::unwrap(from_str(url))) == should_be;
+    }
+
+    #[test]
+    fn test_fragmentless_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org/doc?q=v";
+        assert to_str(result::unwrap(from_str(url))) == url;
+    }
+
+    #[test]
+    fn test_minimal_url_parse_and_format() {
+        let url = ~"http://rust-lang.org/doc";
+        assert to_str(result::unwrap(from_str(url))) == url;
+    }
+
+    #[test]
+    fn test_scheme_host_only_url_parse_and_format() {
+        let url = ~"http://rust-lang.org";
+        assert to_str(result::unwrap(from_str(url))) == url;
+    }
+
+    #[test]
+    fn test_pathless_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org?q=v#something";
+        assert to_str(result::unwrap(from_str(url))) == url;
+    }
+
+    #[test]
+    fn test_scheme_host_fragment_only_url_parse_and_format() {
+        let url = ~"http://rust-lang.org#something";
+        assert to_str(result::unwrap(from_str(url))) == url;
+    }
+
+}

src/libstd/std.rc

@@ -15,7 +15,7 @@
 use core(vers = "0.3");
 import core::*;
 
-export net, net_tcp, net_ip;
+export net, net_tcp, net_ip, net_url;
 export uv, uv_ll, uv_iotask, uv_global_loop;
 export c_vec, util, timer;
 export bitv, deque, fun_treemap, list, map, smallintmap, sort, treemap;
@@ -30,6 +30,7 @@ export base64;
 mod net;
 mod net_ip;
 mod net_tcp;
+mod net_url;
 
 // libuv modules
 mod uv;