examples/sicp_scheme/evaluator.rb in rubasteme-0.1.3 vs examples/sicp_scheme/evaluator.rb in rubasteme-0.1.4

@@ -41,10 +41,13 @@
       when *EV_DEFINITION
         eval_definition(exp, env)
       when *EV_IF
         eval_if(exp, env)
       when *EV_LAMBDA
+        internal_definitions(exp).each { |d|
+          eval_definition(d, env)
+        }
         make_procedure(lambda_parameters(exp),
                        lambda_body(exp),
                        env)
       when *EV_BEGIN
         eval_sequence(begin_actions(exp), env)
@@ -197,12 +200,13 @@
                                      arguments)
       eval_sequence(procedure_body(procedure), extended_env)
     end
 
     def begin_actions(exp)
-      # exp = [:ast_begin, [:ast_*_1], [:ast_*_2], ... ]
-      exp[1..-1]
+      # exp = [:ast_begin, [:ast_sequence]]
+      # sequence = [:ast_sequence, [:ast_*_1], [:ast_*_2], ...]
+      exp[1][1..-1]
     end
 
     def eval_sequence(exps, env)
       if last_exp?(exps)
         self.eval(first_exp(exps), env)
@@ -239,18 +243,27 @@
     def definition_value(exp)
       # exp = [:ast_identifier_definition, [:ast_identifier], [:ast_*]]
       exp[2]
     end
 
+    def internal_definitions(exp)
+      # exp = [:ast_lambda_expression, [:ast_formals], [:ast_body]]
+      # body = [:ast_body, [:ast_internal_definitions], [:ast_sequence]]
+      # internal_definitions = [:ast_intern_definitions, [:ast_definition], ...]
+      exp[2][1][1..-1]
+    end
+
     def lambda_parameters(exp)
-      # exp = [:ast_lambda_expression, [:ast_formals], [:ast_*_1] ...]
+      # exp = [:ast_lambda_expression, [:ast_formals], [:ast_body]]
       formals = exp[1][1..-1]
       formals.map{|node| identifier(node)}
     end
 
     def lambda_body(exp)
-      # exp = [:ast_lambda_expression, [:ast_formals], [:ast_*_1] ...]
-      exp[2..-1]
+      # exp = [:ast_lambda_expression, [:ast_formals], [:ast_body]]
+      # body = [:ast_body, [:ast_internal_definitions], [:ast_sequence]]
+      # sequence = [:ast_sequence, [:ast_*_1], [:ast_*_2], ...]
+      exp[2][2][1..-1]
     end
 
     def make_procedure(parameters, body, env)
       # parameters = [:ast_formals, [:ast_identifier_1], [:ast_identifier_2] ...]
       # body = [[:ast_*_1], [:ast_*_2], ...]