[CLI] Enable command abbreviations.

doc-src/content/CHANGELOG.markdown

@@ -12,6 +12,11 @@ COMPASS CHANGELOG
 * [Compass Core] The configuration constant `$firefox2-ellipsis` has been
   renamed to `$use-mozilla-ellipsis-binding` to reflect the fact that
   it must be used for any version of mozilla less than 3.6.
+* [CLI] The the new Sub-command based CLI will now recognize abbreviated
+  commands as long as the abbreviation is unambiguous.
+  For instance, `compass w` is a shortcut for `compass watch` and
+  `compass com` for `compass compile` but `compas co` will not work
+  for compile because it also matches `compass config`.
 
 0.10.0.rc5 (May 2, 2010)
 ------------------------

lib/compass/commands/registry.rb

@@ -6,11 +6,24 @@ module Compass::Commands
     end
     def get(name)
       @commands ||= Hash.new
-      @commands[name.to_sym]
+      @commands[name.to_sym] || @commands[abbreviation_of(name)]
+    end
+    def abbreviation_of(name)
+      re = /^#{Regexp.escape(name)}/
+      matching = @commands.keys.select{|k| k.to_s =~ re}
+      if matching.size == 1
+        matching.first
+      else
+        raise Compass::Error, "Ambiguous abbreviation '#{name}'. Did you mean one of: #{matching.join(", ")}"
+      end
+    end
+    def abbreviation?(name)
+      re = /^#{Regexp.escape(name)}/
+      @commands.keys.detect{|k| k.to_s =~ re}
     end
     def command_exists?(name)
       @commands ||= Hash.new
-      name && @commands.has_key?(name.to_sym)
+      name && (@commands.has_key?(name.to_sym) || abbreviation?(name))
     end
     def all
       @commands.keys