Updated (display) to use interpreter's instance of Sexpistol.

lib/flea/interpreter.rb

@@ -1,7 +1,9 @@
 module Flea
   class Interpreter
 
-   attr_accessor :base_environment, :current_environment
+   attr_accessor :base_environment, 
+                 :current_environment,
+                 :parser
 
     def initialize(options = {})
       options = {

lib/flea/standard_library/display.scm

@@ -1,6 +1,6 @@
 (define display 
   (native_function "
     output = interpreter.evaluate(arguments[0])
-    print Sexpistol.new.to_sexp(output)
+    print interpreter.parser.to_sexp(output)
     output
   "))

spec/flea/standard_library/display_spec.rb

@@ -19,6 +19,11 @@
       @buffer.string.should == "(1 2 3)"
     end
 
+    it "should output true and false using Scheme external representation" do
+      @interpreter.run('(display #t)(display #f)')
+      @buffer.string.should == "#t#f"
+    end
+
     it "should return the same value that it displayed" do
       result = @interpreter.run('(display "abc")')
       result.should == "abc"