Add constant symbol list, which solves all the symbol allocation problems

[fur] / transformation.py

diff --git a/transformation.py b/transformation.py
index d680145..e3658bc 100644 (file)
--- a/transformation.py
+++ b/transformation.py
@@ -16,6 +16,14 @@ CStringLiteral = collections.namedtuple(
     ],
 )
 
+CSymbolExpression = collections.namedtuple(
+    'CSymbolExpression',
+    [
+        'symbol',
+        'symbol_list_index',
+    ],
+)
+
 CNegationExpression = collections.namedtuple(
     'CNegationExpression',
     [
@@ -71,12 +79,22 @@ CFunctionCallExpression = collections.namedtuple(
     ],
 )
 
+CAssignmentStatement = collections.namedtuple(
+    'CAssignmentStatement',
+    [
+        'target',
+        'target_symbol_list_index',
+        'expression',
+    ],
+)
+
 CProgram = collections.namedtuple(
     'CProgram',
     [
         'builtins',
         'statements',
         'standard_libraries',
+        'symbol_list',
     ],
 )
 
@@ -85,12 +103,21 @@ BUILTINS = {
     'print':    ['stdio.h'],
 }
 
-def transform_expression(builtin_dependencies, expression):
+def transform_expression(builtin_dependencies, symbol_list, expression):
     if isinstance(expression, parsing.FurNegationExpression):
-        return transform_negation_expression(builtin_dependencies, expression)
+        return transform_negation_expression(builtin_dependencies, symbol_list, expression)
 
     if isinstance(expression, parsing.FurFunctionCallExpression):
-        return transform_function_call_expression(builtin_dependencies, expression)
+        return transform_function_call_expression(builtin_dependencies, symbol_list, expression)
+
+    if isinstance(expression, parsing.FurSymbolExpression):
+        if expression.value not in symbol_list:
+            symbol_list.append(expression.value)
+
+        return CSymbolExpression(
+            symbol=expression.value,
+            symbol_list_index=symbol_list.index(expression.value),
+        )
 
     LITERAL_TYPE_MAPPING = {
         parsing.FurIntegerLiteralExpression: CIntegerLiteral,
@@ -109,29 +136,56 @@ def transform_expression(builtin_dependencies, expression):
     }
 
     return INFIX_TYPE_MAPPING[type(expression)](
-        left=transform_expression(builtin_dependencies, expression.left),
-        right=transform_expression(builtin_dependencies, expression.right),
+        left=transform_expression(builtin_dependencies, symbol_list, expression.left),
+        right=transform_expression(builtin_dependencies, symbol_list, expression.right),
     )
 
-def transform_negation_expression(builtin_dependencies, negation_expression):
-    return CNegationExpression(value=transform_expression(builtin_dependencies, negation_expression.value))
+def transform_assignment_statement(builtin_dependencies, symbol_list, assignment_statement):
+    # TODO Check that target is not a builtin
+    if assignment_statement.target not in symbol_list:
+        symbol_list.append(assignment_statement.target)
+
+    return CAssignmentStatement(
+        target=assignment_statement.target,
+        target_symbol_list_index=symbol_list.index(assignment_statement.target),
+        expression=transform_expression(
+            builtin_dependencies,
+            symbol_list,
+            assignment_statement.expression,
+        ),
+    )
 
-def transform_function_call_expression(builtin_dependencies, function_call):
-    if function_call.name in BUILTINS.keys():
-        builtin_dependencies.add(function_call.name)
+def transform_negation_expression(builtin_dependencies, symbol_list, negation_expression):
+    return CNegationExpression(
+        value=transform_expression(builtin_dependencies, symbol_list, negation_expression.value),
+    )
+
+def transform_function_call_expression(builtin_dependencies, symbol_list, function_call):
+    if function_call.function.value in BUILTINS.keys():
+        builtin_dependencies.add(function_call.function.value)
 
         return CFunctionCallExpression(
-            name='builtin$' + function_call.name,
-            arguments=tuple(transform_expression(builtin_dependencies, arg) for arg in function_call.arguments),
+            name='builtin$' + function_call.function.value,
+            arguments=tuple(
+                transform_expression(builtin_dependencies, symbol_list, arg)
+                for arg in function_call.arguments
+            ),
         )
 
     raise Exception()
 
+def transform_statement(builtin_dependencies, symbol_list, statement):
+    return {
+        parsing.FurAssignmentStatement: transform_assignment_statement,
+        parsing.FurFunctionCallExpression: transform_function_call_expression,
+    }[type(statement)](builtin_dependencies, symbol_list, statement)
+
 def transform(program):
     builtins = set()
+    symbol_list = []
 
     c_statements = [
-        transform_function_call_expression(builtins, statement) for statement in program.statement_list
+        transform_statement(builtins, symbol_list, statement) for statement in program.statement_list
     ]
 
     standard_libraries = set()
@@ -143,6 +197,7 @@ def transform(program):
         builtins=builtins,
         statements=c_statements,
         standard_libraries=standard_libraries,
+        symbol_list=symbol_list,
     )