From 8adf2a2d2eabd9ac972603a128448b7f919c6db8 Mon Sep 17 00:00:00 2001
From: quix <quixoticsycophant@gmail.com>
Date: Thu, 14 Jan 2010 19:22:56 -0500
Subject: [PATCH] add redparse compiler

---
 lib/pure/compiler/red_parse.rb    | 62 ++++++++++++++++++++++
 lib/pure/parser/impl/red_parse.rb |  4 ++
 spec/compiler_red_parse_spec.rb   | 85 +++++++++++++++++++++++++++++++
 3 files changed, 151 insertions(+)
 create mode 100644 lib/pure/compiler/red_parse.rb
 create mode 100644 spec/compiler_red_parse_spec.rb

diff --git a/lib/pure/compiler/red_parse.rb b/lib/pure/compiler/red_parse.rb
new file mode 100644
index 0000000..1941bc7
--- /dev/null
+++ b/lib/pure/compiler/red_parse.rb
@@ -0,0 +1,62 @@
+#
+# This file is self-contained, intended for use by an external server.
+#
+# It is not included by the top-level pure.rb.
+#
+ 
+require 'pure/version'
+require 'pure/names'
+require 'redparse'
+ 
+module Pure
+  module Compiler #:nodoc:
+    class RedParse #:nodoc:
+      #
+      # Compiles and evaluates a function spec with arg values.
+      #
+      def evaluate_function(spec, *args)
+        compile_function(spec).send(spec[:name], *args)
+      end
+ 
+      #
+      # Compiles a function spec extracted by
+      # Pure::Parser::RedParse.
+      #
+      # Returns an object which responds to spec[:name].
+      #
+      def compile_function(spec)
+        code_data = (
+          if spec[:origin] == :fun
+            fun_to_define_method(spec[:name], spec[:code])
+          else
+            spec[:code]
+          end
+        )
+ 
+        instance = Names.new(spec[:name], spec[:args])
+        Thread.current[:pure_compiler_input] = code_data.unparse
+ 
+        # use singleton to hide locals
+        class << instance
+          eval(Thread.current[:pure_compiler_input])
+        end
+ 
+        instance
+      end
+ 
+      #
+      # Code-transform `fun' definitions into `define_method' definitions.
+      #
+      def fun_to_define_method(name, code_data)
+        # it's unclear how to create a LiteralNode by hand
+        literal_node = ::RedParse.new(":x").parse
+        literal_node[0] = name
+
+        code_data[1] = "define_method"
+        code_data[2] = [literal_node]
+        code_data
+      end
+    end
+  end
+end
+ 
diff --git a/lib/pure/parser/impl/red_parse.rb b/lib/pure/parser/impl/red_parse.rb
index cc40725..6b5822a 100644
--- a/lib/pure/parser/impl/red_parse.rb
+++ b/lib/pure/parser/impl/red_parse.rb
@@ -8,6 +8,10 @@ class << self
         def extract(mod, method_name, file, line)
           BaseParser.extract(mod, method_name, file, line, Processor)
         end
+
+        def compiler
+          %w[pure/compiler/red_parse Pure::Compiler::RedParse]
+        end
       end
 
       class Processor
diff --git a/spec/compiler_red_parse_spec.rb b/spec/compiler_red_parse_spec.rb
new file mode 100644
index 0000000..310cb10
--- /dev/null
+++ b/spec/compiler_red_parse_spec.rb
@@ -0,0 +1,85 @@
+require File.dirname(__FILE__) + '/pure_spec_base'
+
+require 'pure/parser/red_parse'
+require 'pure/compiler/red_parse'
+
+describe Pure::Compiler::RedParse do
+  before :all do
+    @compiler = Pure::Compiler::RedParse.new
+  end
+
+  it "should transform `fun' definitions to `define_method' definitions" do
+    def_f = pure(Pure::Parser::RedParse) do
+      def f(x, y)
+        x + y
+      end
+    end
+    
+    fun_f = pure(Pure::Parser::RedParse) do
+      fun :f => [:x, :y] do |a, b|
+        a + b
+      end
+    end
+
+    def_g = pure(Pure::Parser::RedParse) do
+      def g
+      end
+    end
+
+    fun_g = pure(Pure::Parser::RedParse) do
+      fun :g do
+      end
+    end
+
+    def_h = pure(Pure::Parser::RedParse) do
+      def h(x)
+        x**2
+      end
+    end
+
+    fun_h = pure(Pure::Parser::RedParse) do
+      fun :h => :x do |a|
+        a**2
+      end
+    end
+
+    fun_i = pure(Pure::Parser::RedParse) do
+      fun :i => [:p, :q] do |*s|
+        s.size
+      end
+    end
+
+    fun_j = pure(Pure::Parser::RedParse) do
+      fun :j => [:p, :q] do |r, *s|
+        r + s
+      end
+    end
+
+    [
+      [:def, def_f, :f, "def f(x,y)\nx+y;\nend"],
+      [:fun, fun_f, :f, "define_method :f do |a, b|\na+b\nend"],
+      [:def, def_g, :g, "def g\n;\nend"],
+      [:fun, fun_g, :g, "define_method :g do \nend"],
+      [:def, def_h, :h, "def h(x)\nx**2;\nend"],
+      [:fun, fun_h, :h, "define_method :h do |a|\na**2\nend"],
+      [:fun, fun_i, :i, "define_method :i do |*s|\ns.size\nend"],
+      [:fun, fun_j, :j, "define_method :j do |r, *s|\nr+s\nend"],
+    ].each { |type, mod, name, expected|
+      entry = Pure::ExtractedFunctions[Pure::Parser::RedParse][mod][name]
+      entry[:code].should be_a(RedParse::Node)
+      code_data = Marshal.load(Marshal.dump(entry[:code]))
+      if entry[:origin] == :fun
+        code_data = @compiler.fun_to_define_method(entry[:name], code_data)
+      end
+      recovered = (
+        code_data.
+        unparse.
+        gsub(%r!\n+!, "\n").
+        gsub(%r!^ +!, "").
+        gsub(%r! +!, " ")
+      )
+      recovered.should == expected
+    }
+  end
+end
+