Move the REPL into its own class

bin/chervil

@@ -3,26 +3,5 @@
 require "chervil"
 require "readline"
 
-def repl(env)
-  begin
-    while line = Readline.readline("> ", true)
-      break if line == "(exit)"
-      lexer = Chervil::Lexer.new(line)
-      tree = Chervil::Parser.new(lexer).parse
-
-      if tree.is_a? Chervil::Error
-        puts tree
-        next
-      end
-
-      results = Chervil::Interpreter.new(tree, env).interpret
-      results.each { |result| puts result unless result.nil? }
-    end
-  rescue Interrupt
-    puts
-    repl(env)
-  end
-end
-
-env = Chervil::Env.new
-repl(env)
+repl = Chervil::Repl.new
+repl.run

lib/chervil.rb

@@ -5,6 +5,7 @@ require 'chervil/error'
 require 'chervil/interpreter'
 require 'chervil/lexer'
 require 'chervil/parser'
+require 'chervil/repl'
 require 'chervil/token'
 require 'chervil/version'
 

lib/chervil/repl.rb

@@ -0,0 +1,28 @@
+module Chervil
+  class Repl
+    def initialize
+      @env = Env.new
+    end
+
+    def run
+      begin
+        while line = Readline.readline("> ", true)
+          break if line == "(exit)"
+          lexer = Lexer.new(line)
+          tree = Parser.new(lexer).parse
+
+          if tree.is_a? Error
+            puts tree
+            next
+          end
+
+          results = Interpreter.new(tree, @env).interpret
+          results.each { |result| puts result unless result.nil? }
+        end
+      rescue Interrupt
+        puts
+        repl(@env)
+      end
+    end
+  end
+end