repl.rb in lisp-1.4.0

- old
+ new
@@ -1,22 +1,67 @@
 #!/usr/bin/env ruby
 require "coolline"
+require "coderay"
 
 module Lisp
-  def self.repl
-    trap("SIGINT") { throw :exit }
-    puts "ctrl-c to exit"
-    catch(:exit) do
-      loop do
-        puts begin
-          eval Coolline.new.readline
-        rescue Exception => e
-          e.message
+  class REPL
+    attr_reader :io, :input
+
+    def initialize
+      @io = Coolline.new do |config|
+        config.transform_proc = proc do
+          CodeRay.scan(config.line, :clojure).term
         end
       end
+
+      reset_input!
     end
-  end
-end
 
-if __FILE__ == $0
-   Lisp.repl
+    def run
+      trap("SIGINT") { throw :exit }
+
+      puts "ctrl-c to exit"
+
+      catch(:exit) do
+        loop do
+          begin
+            @input += io.readline prompt
+
+            if open_count == close_count
+              puts Lisp.eval input
+
+              reset_input!
+            end
+          rescue Exception => e
+            puts e.message
+
+            reset_input!
+          end
+        end
+      end
+    end
+
+    private
+
+    def prompt
+      count = open_count - close_count
+      char  = count > 0 ? ?( : ?)
+      "#{char * count}> "
+    end
+
+    def reset_input!
+      @input = String.new
+    end
+
+    def open_count
+      tokens.count(?()
+    end
+
+    def close_count
+      tokens.count(?))
+    end
+
+    def tokens
+      Lisp.tokenize input
+    end
+  end
 end