Add regexp capturing in rules

lib/rake/task_manager.rb

@@ -275,6 +275,8 @@ def attempt_rule(task_name, task_pattern, args, extensions, block, level)
           return nil
         end
       }
+      match_data = task_pattern.match(task_name)
+      block.binding.eval("proc { |match_data| $~ = match_data }").call(match_data)
       task = FileTask.define_task(task_name, { args => prereqs }, &block)
       task.sources = prereqs
       task
@@ -288,13 +290,23 @@ def make_sources(task_name, task_pattern, extensions)
         when /%/
           task_name.pathmap(ext)
         when %r{/}
-          ext
+          task_pattern.match(task_name)
+          pre_match = Regexp.new("^" + Regexp.quote(Regexp.last_match.pre_match))
+          post_match = Regexp.new(Regexp.quote(Regexp.last_match.post_match) + "$")
+          task_name.sub(task_pattern, ext).sub(pre_match, "").sub(post_match, "")
         when /^\./
           source = task_name.sub(task_pattern, ext)
           source == ext ? task_name.ext(ext) : source
         when String
-          ext
+          task_pattern.match(task_name)
+          pre_match = Regexp.new("^" + Regexp.quote(Regexp.last_match.pre_match))
+          post_match = Regexp.new(Regexp.quote(Regexp.last_match.post_match) + "$")
+          task_name.sub(task_pattern, ext).sub(pre_match, "").sub(post_match, "")
         when Proc, Method
+          if ext.is_a?(Proc)
+            match_data = task_pattern.match(task_name)
+            ext.binding.eval("proc { |match_data| $~ = match_data }").call(match_data)
+          end
           if ext.arity == 1
             ext.call(task_name)
           else

test/test_rake_rules.rb

@@ -409,4 +409,93 @@ def test_works_with_chained_extensions_in_rules
     assert_equal [MINFILE], @runs
   end
 
+  def test_regex_rule_with_proc_dependent_with_capture
+    mkdir_p("src/jw")
+    create_file("src/jw/X.java")
+    rule %r(classes/(.*)\.class) => [
+      proc { "src/#{$1}.java" }
+    ] do |task|
+      assert_equal task.name, "classes/jw/X.class"
+      assert_equal task.source, "src/jw/X.java"
+      assert_equal $1, "jw/X"
+      @runs << :RULE
+    end
+    Task["classes/jw/X.class"].invoke
+    assert_equal [:RULE], @runs
+  end
+
+  def test_regex_rule_with_capture_in_action
+    create_file("icon.svg")
+    rule %r(-(\d+)x(\d+)\.png$) => [
+      ".svg"
+    ] do |task|
+      assert_equal task.name, "icon-160x120.png"
+      assert_equal task.source, "icon.svg"
+      assert_equal $`, "icon"
+      assert_equal $1, "160"
+      assert_equal $2, "120"
+      @runs << :RULE
+    end
+    Task["icon-160x120.png"].invoke
+    assert_equal [:RULE], @runs
+  end
+
+  def test_regex_rule_with_named_capture
+    create_file("icon.png")
+    rule %r(-(?<width>\d+)x(?<height>\d+)\.(?<ext>\w+)$) => [
+      '.\k<ext>'
+    ] do |task|
+      assert_equal task.name, "icon-160x120.png"
+      assert_equal task.source, "icon.png"
+      assert_equal $`, "icon"
+      assert_equal $~[:width], "160"
+      assert_equal $~[:height], "120"
+      assert_equal $~[:ext], "png"
+      @runs << :RULE
+    end
+    Task["icon-160x120.png"].invoke
+    assert_equal [:RULE], @runs
+  end
+
+  def test_regex_rule_with_proc_dependent_with_named_capture
+    mkdir_p("src/jw")
+    create_file("src/jw/X.java")
+    rule %r(classes/(?<basename>.*)\.class$) => [
+      proc { "src/#{$~[:basename]}.java" }
+    ] do |task|
+      assert_equal task.name, "classes/jw/X.class"
+      assert_equal task.source, "src/jw/X.java"
+      assert_equal $1, "jw/X"
+      assert_equal $~[:basename], "jw/X"
+      @runs << :RULE
+    end
+    Task["classes/jw/X.class"].invoke
+    assert_equal [:RULE], @runs
+  end
+
+  def test_regex_rule_with_string_dependent_with_named_capture
+    mkdir_p("src/jw")
+    create_file("src/jw/X.java")
+    rule %r(classes/(?<basename>.*)\.class) => [
+      'src/\k<basename>.java'
+    ] do |task|
+      assert_equal task.name, "classes/jw/X.class"
+      assert_equal task.source, "src/jw/X.java"
+      assert_equal $1, "jw/X"
+      assert_equal $~[:basename], "jw/X"
+      @runs << :RULE
+    end
+    Task["classes/jw/X.class"].invoke
+    assert_equal [:RULE], @runs
+  end
+
+  def test_regex_rule_with_backreference_prematch
+    create_file(SRCFILE)
+    rule ".o" => '\`.c' do |t|
+      @runs << t.name
+    end
+    Task[OBJFILE].invoke
+    assert_equal [OBJFILE], @runs
+  end
+
 end