Implements font parsing

Per specs at http://www.w3.org/TR/CSS21/fonts.html#propdef-font and
http://www.w3.org/TR/CSS/

Author: zmoazeni

lib/csscss.rb

@@ -27,4 +27,5 @@
 require "csscss/parser/border_side"
 require "csscss/parser/border"
 require "csscss/parser/outline"
+require "csscss/parser/font"
 

lib/csscss/parser/common.rb

@@ -5,25 +5,25 @@ module Common
 
       UNITS = %w(px em ex in cm mm pt pc)
 
-      rule(:space)   { match["\s"].repeat(1) }
-      rule(:space?)  { space.maybe }
-      rule(:number)  { match["0-9"] }
-      rule(:numbers) { number.repeat(1) }
-      rule(:decimal) { numbers >> str(".").maybe >> numbers.maybe }
-      rule(:percent) { decimal >> stri("%") >> space? }
-      rule(:length)  { decimal >> stri_list(UNITS) >> space?  }
-      rule(:inherit) { stri("inherit") }
-      rule(:eof)     { any.absent? }
-      rule(:nada)    { any.repeat.as(:nada) }
+      rule(:space)      { match["\s"].repeat(1) }
+      rule(:space?)     { space.maybe }
+      rule(:number)     { match["0-9"] }
+      rule(:numbers)    { number.repeat(1) }
+      rule(:decimal)    { numbers >> str(".").maybe >> numbers.maybe }
+      rule(:percent)    { decimal >> stri("%") >> space? }
+      rule(:length)     { decimal >> stri_list(UNITS) >> space?  }
+      rule(:identifier) { match["a-zA-Z"].repeat(1) }
+      rule(:inherit)    { stri("inherit") }
+      rule(:eof)        { any.absent? }
+      rule(:nada)       { any.repeat.as(:nada) }
 
       rule(:http) {
         (match['a-zA-Z.:/'] | str('\(') | str('\)')).repeat >> space?
       }
 
       rule(:url) {
         stri("url") >> parens do
-          (double_quoted { http } >> space?) |
-          (single_quoted { http } >> space?) |
+          (any_quoted { http } >> space?) |
           http
         end
       }
@@ -65,6 +65,10 @@ def single_quoted(&block)
         between("'", "'", &block)
       end
 
+      def any_quoted(&block)
+        double_quoted(&block) | single_quoted(&block)
+      end
+
       def stri_list(list)
         list.map {|u| stri(u) }.reduce(:|)
       end

lib/csscss/parser/font.rb

@@ -0,0 +1,96 @@
+module Csscss
+  module Parser
+    module Font
+      extend Parser::Base
+
+      class Parser < Parslet::Parser
+        include Common
+
+        rule(:literal_font) {
+          symbol_list(%w(caption icon menu message-box
+                        small-caption status-bar))
+        }
+
+        rule(:font_style) { symbol_list(%w(normal italic oblique)) }
+        rule(:font_variant) { symbol_list(%w(normal small-caps)) }
+        rule(:font_weight) {
+          symbol_list(%w(normal bold bolder lighter 100 200 300 400 500 600 700 800 900))
+        }
+
+        rule(:font_size_absolute) {
+          symbol_list(%w(xx-small x-small small medium
+                         large x-large xx-large))
+        }
+
+        rule(:font_size_relative) { symbol_list(%w(larger smaller)) }
+
+        rule(:font_size) {
+          font_size_absolute | font_size_relative | length | percent
+        }
+
+        rule(:line_height) {
+          symbol("/") >> (
+            symbol("normal") | (length | percent | numbers) >> space?
+          ).as(:line_height_value)
+        }
+
+        rule(:font_family) {
+          family = identifier | any_quoted { identifier >> (space? >> identifier).repeat }
+          family >> (symbol(",") >> font_family).maybe
+        }
+
+        rule(:font) {
+          (
+           symbol("inherit") >> eof | (
+             (
+               literal_font.maybe.as(:literal_font) |
+               font_style.maybe.as(:font_style) >>
+               font_variant.maybe.as(:font_variant) >>
+               font_weight.maybe.as(:font_weight) >>
+
+               font_size.as(:font_size) >>
+               line_height.maybe.as(:line_height) >>
+               font_family.as(:font_family)
+             )
+           )
+          ).as(:font)
+        }
+        root(:font)
+      end
+
+      class Transformer < Parslet::Transform
+        rule(font: simple(:inherit)) {[]}
+        rule(font: {literal_font:simple(:literal)}) {[]}
+
+        rule(line_height_value: simple(:value)) { value }
+
+        rule(font: {
+          font_style: simple(:font_style),
+          font_variant: simple(:font_variant),
+          font_weight: simple(:font_weight),
+          font_size: simple(:font_size),
+          line_height: simple(:line_height),
+          font_family: simple(:font_family)
+        }) {|context|
+          [].tap do |declarations|
+            context.each do |property, value|
+              declarations << Declaration.from_parser(property.to_s.gsub("_", "-"), value, property != :font_family) if value
+            end
+          end
+        }
+
+        #rule(outline: {
+          #outline_width:simple(:width),
+          #outline_style:simple(:style),
+          #outline_color:simple(:color)
+        #}) {
+          #[].tap do |declarations|
+            #declarations << Declaration.from_parser("outline-width", width) if width
+            #declarations << Declaration.from_parser("outline-style", style) if style
+            #declarations << Declaration.from_parser("outline-color", color) if color
+          #end
+        #}
+      end
+    end
+  end
+end

lib/csscss/redundancy_analyzer.rb

@@ -119,6 +119,7 @@ def shorthand_parser(property)
       when "border-style" then Parser::BorderStyle
       when "border-color" then Parser::BorderColor
       when "outline"      then Parser::Outline
+      when "font"         then Parser::Font
       when "border-top", "border-right", "border-bottom", "border-left"
         Parser::BorderSide
       end

lib/csscss/types.rb

@@ -4,8 +4,10 @@ def self.from_csspool(dec)
       new(dec.property.to_s.downcase, dec.expressions.join(" ").downcase)
     end
 
-    def self.from_parser(property, value)
-      new(property.to_s, value.to_s.downcase.strip)
+    def self.from_parser(property, value, clean = true)
+      value = value.to_s
+      value = value.downcase if clean
+      new(property.to_s, value.strip)
     end
 
     def derivative?

test/csscss/parser/font_test.rb

@@ -0,0 +1,43 @@
+require "test_helper"
+
+module Csscss::Parser
+  module Font
+    describe self do
+      include CommonParserTests
+
+      before do
+        @parser = Parser.new
+        @trans = Transformer.new
+      end
+
+      it "converts shorthand rules to longhand" do
+        trans("10% Gill, 'Lucida Sans'").must_equal([
+          dec("font-size", "10%"),
+          dec("font-family", "Gill, 'Lucida Sans'")
+        ])
+
+        trans("normal small-caps 100 10% / 33 Gill, Helvetica, \"Lucida Sans\", cursive").must_equal([
+          dec("font-style", "normal"),
+          dec("font-variant", "small-caps"),
+          dec("font-weight", "100"),
+          dec("font-size", "10%"),
+          dec("line-height", "33"),
+          dec("font-family", 'Gill, Helvetica, "Lucida Sans", cursive')
+        ])
+      end
+
+      it "parses font family" do
+        @parser.font_family.must_parse("\"Lucida\"")
+        @parser.font_family.must_parse("\"Lucida Sans\"")
+        @parser.font_family.must_parse("Gill")
+        @parser.font_family.must_parse('Gill, Helvetica, "Lucida Sans", cursive')
+      end
+
+      it "ignores literal fonts" do
+        trans("caption").must_equal([])
+        trans("icon").must_equal([])
+        trans("menu").must_equal([])
+      end
+    end
+  end
+end