Fixed function definitions

lib/kalc/ast.rb

@@ -159,29 +159,23 @@ def eval(context)
     end
 
     class FunctionDefinition
-      attr_reader :name
-      attr_reader :argument_list
-      attr_reader :body
-
       def initialize(name, argument_list, body)
         @name = name
         @argument_list = argument_list
         @body = body
       end
 
       def eval(context)
-        context.add_function(@name.to_sym, lambda { |parent_context, *argument_list|
+        context.add_function(@name.to_sym, lambda { |parent_context, *args|
+          dup_body = @body.dup
           cxt = Environment.new(parent_context)
-
-          argument_list.each_with_index do |arg, idx|
-            cxt.add_variable(argument_list[idx].value, arg.eval(cxt))
+          args.each_with_index do |arg, idx|
+            cxt.add_variable(@argument_list[idx].value, arg.eval(cxt))
           end
-
-          @body.eval(cxt)
+          dup_body.eval(cxt)
         })
-        context.get_function(@name)
+        nil
       end
     end
-
   end
 end

lib/kalc/grammar.rb

@@ -246,9 +246,9 @@ def self.operators(operators={})
   }
 
   rule(:function_definition_expression) {
-    (str('DEF ') >> identifier.as(:name) >>
-      paren_argument_list.as(:argument_list) >> 
-      left_brace >> function_body.as(:body) >> right_brace).as(:function_definition) |
+    (str('DEFINE') >> spaces? >> identifier.as(:name) >>
+         paren_argument_list.as(:argument_list) >>
+         left_brace >> function_body.as(:body) >> right_brace).as(:function_definition) |
     expressions.as(:expressions)
   }
 

lib/kalc/interpreter.rb

@@ -1,14 +1,13 @@
 # Code inspired by https://github.com/txus/schemer
 
+require 'pp'
+
 module Kalc
   class Interpreter
 
     attr_reader :env
 
-    def initialize(ast = nil)
-
-      @ast = ast
-
+    def initialize
       @env = Environment.new do |env|
 
         env.add_function(:IF, lambda { |cxt, cond, if_true, if_false|
@@ -85,12 +84,19 @@ def initialize(ast = nil)
           })
         end
 
+        env.add_function(:P, lambda { |cxt, *output|  
+          p output
+        })
+
+        env.add_function(:PP, lambda { |cxt, *output|  
+          pp output
+        })
+
       end
     end
 
-    def run(ast = nil)
-      @ast = ast if ast
-      @ast.eval(@env)
+    def run(ast)
+      ast.eval(@env)
     end
   end
 end