Added lambda expressions
[fur] / transformation.py
index 81c1e5d..e8ee51c 100644 (file)
@@ -1,7 +1,6 @@
 import collections
 
-import normalization
-import parsing
+import conversion
 
 CIntegerLiteral = collections.namedtuple(
     'CIntegerLiteral',
@@ -18,13 +17,6 @@ CStringLiteral = collections.namedtuple(
     ],
 )
 
-CConstantExpression = collections.namedtuple(
-    'CConstantExpression',
-    [
-        'value'
-    ],
-)
-
 CVariableExpression = collections.namedtuple(
     'CVariableExpression',
     [
@@ -40,31 +32,32 @@ CSymbolExpression = collections.namedtuple(
     ],
 )
 
-CNegationExpression = collections.namedtuple(
-    'CNegationExpression',
+CStructureLiteralExpression = collections.namedtuple(
+    'CStructureLiteralExpression',
     [
-        'value',
+        'field_count',
+        'symbol_list_variable',
+        'value_list_variable',
     ],
 )
 
-CFunctionCallForFurInfixOperator = collections.namedtuple(
-    'CFunctionCallForFurInfixOperator',
-    [
-        'name',
-        'left',
-        'right',
-    ],
+CPushStatement = collections.namedtuple(
+    'CPushStatement',
+    (
+        'expression',
+    ),
 )
 
 CFunctionCallExpression = collections.namedtuple(
     'CFunctionCallExpression',
-    [
-        'name',
+    (
+        'metadata',
+        'function_expression',
         'argument_count',
-        'argument_items',
-    ],
+    ),
 )
 
+# TODO We are currently not changing variables, just preventing them from being accessed.
 CSymbolAssignmentStatement = collections.namedtuple(
     'CSymbolAssignmentStatement',
     [
@@ -82,6 +75,15 @@ CArrayVariableInitializationStatement = collections.namedtuple(
     ],
 )
 
+CSymbolArrayVariableInitializationStatement = collections.namedtuple(
+    'CSymbolArrayVariableInitializationStatement',
+    [
+        'variable',
+        'symbol_list',
+        'symbol_list_indices',
+    ],
+)
+
 CVariableInitializationStatement = collections.namedtuple(
     'CVariableInitializationStatement',
     [
@@ -109,8 +111,8 @@ CIfElseStatement = collections.namedtuple(
     'CIfElseStatement',
     [
         'condition_expression',
-        'if_statements',
-        'else_statements',
+        'if_statement_list',
+        'else_statement_list',
     ],
 )
 
@@ -121,10 +123,13 @@ CFunctionDeclaration = collections.namedtuple(
     ],
 )
 
+# TODO If a function definition doesn't end with an expression, we have issues currently because we try to return statement.
+# TODO Closures currently wrap entire defining environment, even symbols that are not used, which makes garbage collection ineffective.
 CFunctionDefinition = collections.namedtuple(
     'CFunctionDefinition',
     [
         'name',
+        'argument_name_list',
         'statement_list',
     ],
 )
@@ -134,6 +139,7 @@ CProgram = collections.namedtuple(
     [
         'builtin_set',
         'function_definition_list',
+        'operator_declarations',
         'statements',
         'standard_libraries',
         'string_literal_list',
@@ -141,59 +147,20 @@ CProgram = collections.namedtuple(
     ],
 )
 
-EQUALITY_LEVEL_OPERATOR_TO_FUNCTION_NAME_MAPPING = {
-    '==':   'equals',
-    '!=':   'notEquals',
-    '<=':   'lessThanOrEqual',
-    '>=':   'greaterThanOrEqual',
-    '<':    'lessThan',
-    '>':    'greaterThan',
-}
-
-def transform_comparison_level_expression(accumulators, expression):
-    # Transform expressions like 1 < 2 < 3 into expressions like 1 < 2 && 2 < 3
-    if isinstance(expression.left, parsing.FurInfixExpression) and expression.left.order == 'comparison_level':
-        left = transform_comparison_level_expression(
-            accumulators,
-            expression.left
-        )
-
-        middle = left.right
-
-        right = transform_expression(
-            accumulators,
-            expression.right,
-        )
-
-        # TODO Don't evaluate the middle expression twice
-        return CFunctionCallForFurInfixOperator(
-            name='and',
-            left=left,
-            right=CFunctionCallForFurInfixOperator(
-                name=EQUALITY_LEVEL_OPERATOR_TO_FUNCTION_NAME_MAPPING[expression.operator],
-                left=middle,
-                right=right,
-            ),
-        )
-
-    return CFunctionCallForFurInfixOperator(
-        name=EQUALITY_LEVEL_OPERATOR_TO_FUNCTION_NAME_MAPPING[expression.operator],
-        left=transform_expression(accumulators, expression.left),
-        right=transform_expression(accumulators, expression.right),
-    )
-
 BUILTINS = {
-    'false':    [],
-    'pow':      ['math.h'],
-    'print':    ['stdio.h'],
-    'true':     [],
+    'concatenate':      [],
+    'false':            [],
+    'pow':              ['math.h'],
+    'print':            ['stdio.h'],
+    'true':             [],
 }
 
 def transform_variable_expression(accumulators, expression):
+    assert isinstance(expression, conversion.CPSVariableExpression)
     return CVariableExpression(variable=expression.variable)
 
-def transform_string_literal(accumulators, expression):
-    value = expression.value
+def transform_string_literal_expression(accumulators, expression):
+    value = expression.string
 
     try:
         index = accumulators.string_literal_list.index(value)
@@ -204,111 +171,126 @@ def transform_string_literal(accumulators, expression):
     return CStringLiteral(index=index, value=value)
 
 def transform_symbol_expression(accumulators, expression):
-    if expression.value in ['true', 'false']:
-        return CConstantExpression(value=expression.value)
+    if expression.symbol in BUILTINS:
+        accumulators.builtin_set.add(expression.symbol)
 
-    if expression.value not in accumulators.symbol_list:
-        symbol_list.append(expression.value)
+    try:
+        symbol_list_index = accumulators.symbol_list.index(expression.symbol)
+    except ValueError:
+        symbol_list_index = len(accumulators.symbol_list)
+        accumulators.symbol_list.append(expression.symbol)
 
     return CSymbolExpression(
-        symbol=expression.value,
-        symbol_list_index=accumulators.symbol_list.index(expression.value),
+        symbol=expression.symbol,
+        symbol_list_index=symbol_list_index,
     )
 
-def transform_infix_expression(accumulators, expression):
-    if expression.order == 'comparison_level':
-        return transform_comparison_level_expression(accumulators, expression)
-
-    INFIX_OPERATOR_TO_FUNCTION_NAME = {
-        '+':    'add',
-        '-':    'subtract',
-        '*':    'multiply',
-        '//':   'integerDivide',
-        '%':    'modularDivide',
-        'and':  'and',
-        'or':   'or',
-    }
-
-    return CFunctionCallForFurInfixOperator(
-        name=INFIX_OPERATOR_TO_FUNCTION_NAME[expression.operator],
-        left=transform_expression(accumulators, expression.left),
-        right=transform_expression(accumulators, expression.right),
+def transform_integer_literal_expression(accumulators, expression):
+    return CIntegerLiteral(value=expression.integer)
+
+CListConstructExpression = collections.namedtuple(
+    'CListConstructExpression',
+    (
+        'allocate',
+    ),
+)
+
+CLambdaExpression = collections.namedtuple(
+    'CLambdaExpression',
+    (
+        'name',
+    ),
+)
+
+CListAppendStatement = collections.namedtuple(
+    'CListAppendStatement',
+    (
+        'list_expression',
+        'item_expression',
+    ),
+)
+
+def transform_structure_literal_expression(accumulators, expression):
+    return CStructureLiteralExpression(
+        field_count=expression.field_count,
+        symbol_list_variable=expression.symbol_list_variable,
+        value_list_variable=expression.value_list_variable,
     )
 
-def transform_integer_literal_expression(accumulators, expression):
-    return CIntegerLiteral(value=expression.value)
+def transform_lambda_expression(accumulators, expression):
+    # TODO This function feels hacky
+    if len(accumulators.lambda_number_list) == 0:
+        accumulators.lambda_number_list.append(0)
+    else:
+        accumulators.lambda_number_list.append(accumulators.lambda_number_list[-1] + 1)
+
+    name = '__lambda_{}'.format(accumulators.lambda_number_list[-1])
+
+    accumulators.function_definition_list.append(CFunctionDefinition(
+        name=name,
+        argument_name_list=expression.argument_name_list,
+        statement_list=tuple(transform_statement(accumulators, s) for s in expression.statement_list),
+    ))
+
+    return CLambdaExpression(name=name)
+
+
+def transform_list_construct_expression(accumulators, expression):
+    return CListConstructExpression(allocate=expression.allocate)
 
-def transform_parenthesized_expression(accumulators, expression):
-    # Parentheses can be removed because everything in the C output is explicitly parenthesized
-    return transform_expression(accumulators, expression.internal)
+def transform_list_append_statement(accumulators, expression):
+    return CListAppendStatement(
+        list_expression=transform_expression(accumulators, expression.list_expression),
+        item_expression=transform_expression(accumulators, expression.item_expression),
+    )
 
 def transform_expression(accumulators, expression):
-    # TODO Clean up handlers for parsing expressions
     return {
-        parsing.FurFunctionCallExpression: transform_function_call_expression,
-        parsing.FurInfixExpression: transform_infix_expression,
-        parsing.FurIntegerLiteralExpression: transform_integer_literal_expression,
-        parsing.FurNegationExpression: transform_negation_expression,
-        parsing.FurParenthesizedExpression: transform_parenthesized_expression,
-        parsing.FurStringLiteralExpression: transform_string_literal,
-        parsing.FurSymbolExpression: transform_symbol_expression,
-        normalization.NormalFunctionCallExpression: transform_function_call_expression,
-        normalization.NormalInfixExpression: transform_infix_expression,
-        normalization.NormalNegationExpression: transform_negation_expression,
-        normalization.NormalVariableExpression: transform_variable_expression,
+        conversion.CPSFunctionCallExpression: transform_function_call_expression,
+        conversion.CPSIntegerLiteralExpression: transform_integer_literal_expression,
+        conversion.CPSLambdaExpression: transform_lambda_expression,
+        conversion.CPSListConstructExpression: transform_list_construct_expression,
+        conversion.CPSStructureLiteralExpression: transform_structure_literal_expression,
+        conversion.CPSStringLiteralExpression: transform_string_literal_expression,
+        conversion.CPSSymbolExpression: transform_symbol_expression,
+        conversion.CPSVariableExpression: transform_variable_expression,
     }[type(expression)](accumulators, expression)
 
 def transform_symbol_assignment_statement(accumulators, assignment_statement):
     # TODO Check that target is not a builtin
-    if assignment_statement.target not in accumulators.symbol_list:
+    try:
+        symbol_list_index = accumulators.symbol_list.index(assignment_statement.target)
+    except ValueError:
+        symbol_list_index = len(accumulators.symbol_list)
         accumulators.symbol_list.append(assignment_statement.target)
 
     return CSymbolAssignmentStatement(
         target=assignment_statement.target,
-        target_symbol_list_index=accumulators.symbol_list.index(assignment_statement.target),
+        target_symbol_list_index=symbol_list_index,
         expression=transform_expression(
             accumulators,
             assignment_statement.expression,
         ),
     )
 
-def transform_negation_expression(accumulators, expression):
-    return CNegationExpression(
-        value=transform_expression(accumulators, expression.internal_expression),
-    )
-
 def transform_function_call_expression(accumulators, function_call):
-    if function_call.function.value in BUILTINS.keys():
-        # TODO Check that the builtin is actually callable
-        accumulators.builtin_set.add(function_call.function.value)
-
     # TODO Use the symbol from SYMBOL LIST
     return CFunctionCallExpression(
-        name=function_call.function.value,
+        metadata=function_call.metadata,
+        function_expression=transform_expression(accumulators, function_call.function_expression),
         argument_count=function_call.argument_count,
-        argument_items=transform_expression(accumulators, function_call.argument_items),
     )
 
 def transform_expression_statement(accumulators, statement):
-    # TODO At some point we can verify that all expression types are supported and just call transform_expression
-    expression = {
-        parsing.FurFunctionCallExpression: transform_function_call_expression,
-        parsing.FurInfixExpression: transform_expression,
-        parsing.FurIntegerLiteralExpression: transform_expression,
-        parsing.FurSymbolExpression: transform_expression,
-        normalization.NormalFunctionCallExpression: transform_function_call_expression,
-        normalization.NormalVariableExpression: transform_expression,
-    }[type(statement.expression)](accumulators, statement.expression)
-
     return CExpressionStatement(
-        expression=expression,
+        expression=transform_expression(accumulators, statement.expression),
     )
 
 def transform_if_else_statement(accumulators, statement):
     return CIfElseStatement(
         condition_expression=transform_expression(accumulators, statement.condition_expression),
-        if_statements=tuple(transform_statement(accumulators, s) for s in statement.if_statements),
-        else_statements=tuple(transform_statement(accumulators, s) for s in statement.else_statements),
+        if_statement_list=tuple(transform_statement(accumulators, s) for s in statement.if_statement_list),
+        else_statement_list=tuple(transform_statement(accumulators, s) for s in statement.else_statement_list),
     )
 
 def transform_array_variable_initialization_statement(accumulators, statement):
@@ -317,6 +299,24 @@ def transform_array_variable_initialization_statement(accumulators, statement):
         items=tuple(transform_expression(accumulators, i) for i in statement.items),
     )
 
+def transform_symbol_array_variable_initialization_statement(accumulators, statement):
+    symbol_list_indices = []
+
+    for symbol in statement.symbol_list:
+        try:
+            symbol_list_index = accumulators.symbol_list.index(symbol)
+        except ValueError:
+            symbol_list_index = len(accumulators.symbol_list)
+            accumulators.symbol_list.append(symbol)
+
+        symbol_list_indices.append(symbol_list_index)
+
+    return CSymbolArrayVariableInitializationStatement(
+        variable=statement.variable,
+        symbol_list=statement.symbol_list,
+        symbol_list_indices=tuple(symbol_list_indices),
+    )
+
 def transform_variable_initialization_statement(accumulators, statement):
     return CVariableInitializationStatement(
         variable=statement.variable,
@@ -334,23 +334,30 @@ def transform_function_definition_statement(accumulators, statement):
     if any(fd.name == statement.name for fd in accumulators.function_definition_list):
         raise Exception('A function with name "{}" already exists'.format(statement.name))
 
+    # TODO Add argument names to the symbol table
     accumulators.function_definition_list.append(CFunctionDefinition(
         name=statement.name,
+        argument_name_list=statement.argument_name_list,
         statement_list=tuple(transform_statement(accumulators, s) for s in statement.statement_list)
     ))
 
     return CFunctionDeclaration(name=statement.name)
 
+def transform_push_statement(accumulators, statement):
+    return CPushStatement(expression=transform_expression(accumulators, statement.expression))
+
 def transform_statement(accumulators, statement):
     return {
-        parsing.FurAssignmentStatement: transform_symbol_assignment_statement,
-        parsing.FurExpressionStatement: transform_expression_statement,
-        normalization.NormalArrayVariableInitializationStatement: transform_array_variable_initialization_statement,
-        normalization.NormalExpressionStatement: transform_expression_statement,
-        normalization.NormalFunctionDefinitionStatement: transform_function_definition_statement,
-        normalization.NormalIfElseStatement: transform_if_else_statement,
-        normalization.NormalVariableInitializationStatement: transform_variable_initialization_statement,
-        normalization.NormalVariableReassignmentStatement: transform_variable_reassignment_statement,
+        conversion.CPSArrayVariableInitializationStatement: transform_array_variable_initialization_statement,
+        conversion.CPSAssignmentStatement: transform_symbol_assignment_statement,
+        conversion.CPSExpressionStatement: transform_expression_statement,
+        conversion.CPSFunctionDefinitionStatement: transform_function_definition_statement,
+        conversion.CPSIfElseStatement: transform_if_else_statement,
+        conversion.CPSListAppendStatement: transform_list_append_statement,
+        conversion.CPSPushStatement: transform_push_statement,
+        conversion.CPSSymbolArrayVariableInitializationStatement: transform_symbol_array_variable_initialization_statement,
+        conversion.CPSVariableInitializationStatement: transform_variable_initialization_statement,
+        conversion.CPSVariableReassignmentStatement: transform_variable_reassignment_statement,
     }[type(statement)](accumulators, statement)
 
 
@@ -359,6 +366,7 @@ Accumulators = collections.namedtuple(
     [
         'builtin_set',
         'function_definition_list',
+        'lambda_number_list',
         'operator_set',
         'symbol_list',
         'string_literal_list',
@@ -369,6 +377,7 @@ def transform(program):
     accumulators = Accumulators(
         builtin_set=set(),
         function_definition_list=[],
+        lambda_number_list=[],
         operator_set=set(),
         symbol_list=[],
         string_literal_list=[],
@@ -386,6 +395,7 @@ def transform(program):
     return CProgram(
         builtin_set=accumulators.builtin_set,
         function_definition_list=accumulators.function_definition_list,
+        operator_declarations=tuple(sorted(accumulators.operator_set)),
         statements=statement_list,
         standard_libraries=standard_library_set,
         string_literal_list=accumulators.string_literal_list,