Re-factored if command execution visitor phase.

6 files changed, 53 insertions, 33 deletions

diff --git a/src/pclc/parser/command.py b/src/pclc/parser/command.py
index 9fc074b..ac749b4 100644
--- a/src/pclc/parser/command.py
+++ b/src/pclc/parser/command.py
@@ -143,25 +143,36 @@ class IfCommand(Entity, ResolutionSymbols):
         def __init__(self, filename, lineno, commands, if_command):
             IfCommand.Block.__init__(self, filename, lineno, commands, if_command)
 
+    class EndIf(Entity):
+         def __init__(self, filename, lineno, if_command):
+            Entity.__init__(self, filename, lineno)
+            self.if_command = if_command
+
+         def accept(self, visitor):
+             visitor.visit(self)
+
     def __init__(self,
                  filename,
                  lineno,
                  identifier,
                  condition,
                  then_commands,
-                 else_commands):
+                 else_commands,
+                 endif_lineno):
         Entity.__init__(self, filename, lineno)
         ResolutionSymbols.__init__(self)
         self.identifier = identifier
         self.condition = condition
         self.then_commands = IfCommand.ThenBlock(filename, then_commands[0].lineno, then_commands, self)
         self.else_commands = IfCommand.ElseBlock(filename, else_commands[0].lineno, else_commands, self)
+        self.endif = IfCommand.EndIf(filename, endif_lineno, self)
 
     def accept(self, visitor):
+        visitor.visit(self)
         self.condition.accept(visitor)
         self.then_commands.accept(visitor)
         self.else_commands.accept(visitor)
-        visitor.visit(self)
+        self.endif.accept(visitor)
 
     def __str__(self):
         f = lambda cmd: str(cmd)
diff --git a/src/pclc/parser/pcl_parser.py b/src/pclc/parser/pcl_parser.py
index 397a323..925b631 100644
--- a/src/pclc/parser/pcl_parser.py
+++ b/src/pclc/parser/pcl_parser.py
@@ -399,12 +399,12 @@ def p_do_command(p):
         # len(p) == 12
         p[6].append(p[7])
         p[9].append(p[10])
-        p[0].append(IfCommand(p.parser.filename, p[1].lineno, p[1], p[4], p[6], p[9]))
+        p[0].append(IfCommand(p.parser.filename, p[1].lineno, p[1], p[4], p[6], p[9], p.lineno(11)))
     elif len(p) > 9:
         # len(p) == 10
         p[4].append(p[5])
         p[7].append(p[8])
-        p[0].append(IfCommand(p.parser.filename, p.lineno(1), None, p[2], p[4], p[7]))
+        p[0].append(IfCommand(p.parser.filename, p.lineno(1), None, p[2], p[4], p[7], p.lineno(9)))
     elif len(p) > 6:
         # len(p) == 7
         p[0].append(LetCommand(p.parser.filename, p.lineno(1), p[1], p[4], p[6]))
diff --git a/src/pclc/visitors/do_executor_visitor.py b/src/pclc/visitors/do_executor_visitor.py
index 1e2d345..a198fc2 100644
--- a/src/pclc/visitors/do_executor_visitor.py
+++ b/src/pclc/visitors/do_executor_visitor.py
@@ -106,21 +106,22 @@ class IntermediateRepresentation(object):
         self.__func_table = dict()
         self.__func_no = 0
 
-    def push_command_action(self, command):
-        node = IntermediateRepresentation.IRCommandNode(command, self.__current_node)
+    def __add_node(self, node, update_current_node = True):
         if node.parent is None:
             self.__root.append(node)
         else:
             self.__current_node.add_child(node)
-        self.__current_node = node
 
-    def push_then_block(self, then_block):
-        node = IntermediateRepresentation.IRIfNode(then_block.if_command, self.__current_node)
-        if node.parent is None:
-            self.__root.append(node)
-        else:
-            self.__current_node.add_child(node)
-        self.__current_node = node
+        if update_current_node:
+            self.__current_node = node
+
+    def push_command_action(self, command):
+        node = IntermediateRepresentation.IRCommandNode(command, self.__current_node)
+        self.__add_node(node)
+
+    def push_if_action(self, if_command):
+        node = IntermediateRepresentation.IRIfNode(if_command, self.__current_node)
+        self.__add_node(node)
         self.__current_if = node
 
     def mark_else_block(self):
@@ -133,18 +134,11 @@ class IntermediateRepresentation(object):
 
     def push_return_action(self, return_command):
         node = IntermediateRepresentation.IRReturnNode(return_command, self.__current_node)
-        if node.parent is None:
-            self.__root.append(node)
-        else:
-            self.__current_node.add_child(node)
+        self.__add_node(node, False)
 
     def push_let_action(self, let_command):
         node = IntermediateRepresentation.IRLetNode(let_command, self.__current_node)
-        if node.parent is None:
-            self.__root.append(node)
-        else:
-            self.__current_node.add_child(node)
-        self.__current_node = node
+        self.__add_node(node)
         self.__current_let = node
 
     def mark_let_end(self, let_expression_function):
@@ -248,7 +242,7 @@ class IntermediateRepresentation(object):
             scope = return_command['scope']
 
             if return_command.value:
-                code.append(("return %s" % executor_visitor._generate_terminal(return_command.value, scope)))
+                code.append(("return %s" % executor_visitor._generate_terminal(return_command.value, scope), ""))
             elif len(return_command.mappings) == 0:
                 code.append(("return None", ""))
             else:
@@ -365,16 +359,20 @@ class DoExecutorVisitor(ExecutorVisitor):
 
     @multimethod(IfCommand)
     def visit(self, if_command):
-        self.__ir.mark_endif()
+        self.__ir.push_if_action(if_command)
 
     @multimethod(IfCommand.ThenBlock)
     def visit(self, then_block):
-        self.__ir.push_then_block(then_block)
+        pass
 
     @multimethod(IfCommand.ElseBlock)
     def visit(self, else_block):
         self.__ir.mark_else_block()
 
+    @multimethod(IfCommand.EndIf)
+    def visit(self, end_if):
+        self.__ir.mark_endif()
+
     @multimethod(LetCommand)
     def visit(self, let_command):
         self.__ir.push_let_action(let_command)
diff --git a/src/pclc/visitors/first_pass_resolver_visitor.py b/src/pclc/visitors/first_pass_resolver_visitor.py
index eb4c1e4..6d26f1b 100644
--- a/src/pclc/visitors/first_pass_resolver_visitor.py
+++ b/src/pclc/visitors/first_pass_resolver_visitor.py
@@ -915,12 +915,12 @@ class FirstPassResolverVisitor(ResolverVisitor):
 
         # Check if assignment variable has been used already. Code generation may not
         # generate all code to provide the previous use!
-        if identifier in self._current_scope:
-            self._add_warnings("WARNING: %(filename)s at line %(lineno)d, duplicate assignment variable %(var_name)s",
-                               [identifier],
-                               lambda i: {'filename' : i.filename,
-                                          'lineno' : i.lineno,
-                                          'var_name' : i})
+        if self._current_scope.in_current_scope(identifier):
+            self._add_errors("ERROR: %(filename)s at line %(lineno)d, duplicate assignment variable %(var_name)s",
+                             [identifier],
+                             lambda i: {'filename' : i.filename,
+                                        'lineno' : i.lineno,
+                                        'var_name' : i})
         else:
             # Record the assignment and the command
             self._current_scope[identifier] = assign_object
@@ -992,7 +992,7 @@ class FirstPassResolverVisitor(ResolverVisitor):
         # Record the current scope in the entity's resolution symbols
         if_command['scope'] = self._current_scope
 
-        self._current_scope = self._current_scope.get_parent()
+        # Resolve the assignment if there is one
         if if_command.identifier:
             self.__resolve_assignment(if_command.identifier, if_command)
 
@@ -1009,6 +1009,10 @@ class FirstPassResolverVisitor(ResolverVisitor):
         previous_scope.add_nested_scope(else_scope)
         self._current_scope = else_scope
 
+    @multimethod(IfCommand.EndIf)
+    def visit(self, end_if):
+        self._current_scope = self._current_scope.get_parent()
+
     @multimethod(LetCommand)
     def visit(self, let_command):
         # Record the current scope in the entity's resolution symbols
diff --git a/src/pclc/visitors/second_pass_resolver_visitor.py b/src/pclc/visitors/second_pass_resolver_visitor.py
index f384f94..ff682a7 100644
--- a/src/pclc/visitors/second_pass_resolver_visitor.py
+++ b/src/pclc/visitors/second_pass_resolver_visitor.py
@@ -151,6 +151,10 @@ class SecondPassResolverVisitor(FirstPassResolverVisitor):
     def visit(self, else_block):
         pass
 
+    @multimethod(IfCommand.EndIf)
+    def visit(self, end_if):
+        pass
+
     @multimethod(LetCommand)
     def visit(self, let_command):
         pass
diff --git a/src/pclc/visitors/symbol_table.py b/src/pclc/visitors/symbol_table.py
index 98492c7..fe5cb37 100644
--- a/src/pclc/visitors/symbol_table.py
+++ b/src/pclc/visitors/symbol_table.py
@@ -29,6 +29,9 @@ class SymbolTable(object):
     def get_parent(self):
         return self.__parent
 
+    def in_current_scope(self, key):
+        return key in self.__table
+
     def __getitem__(self, key):
         return self.__table[key]