Normalize comparison expressions, even ternary comparison expressions
[fur] / transformation.py
index e84a4bc..b6d21c8 100644 (file)
@@ -1,5 +1,6 @@
 import collections
 
+import normalization
 import parsing
 
 CIntegerLiteral = collections.namedtuple(
@@ -12,6 +13,7 @@ CIntegerLiteral = collections.namedtuple(
 CStringLiteral = collections.namedtuple(
     'CStringLiteral',
     [
+        'index',
         'value',
     ],
 )
@@ -23,6 +25,13 @@ CConstantExpression = collections.namedtuple(
     ],
 )
 
+CVariableExpression = collections.namedtuple(
+    'CVariableExpression',
+    [
+        'variable',
+    ],
+)
+
 CSymbolExpression = collections.namedtuple(
     'CSymbolExpression',
     [
@@ -38,115 +47,43 @@ CNegationExpression = collections.namedtuple(
     ],
 )
 
-CAdditionExpression = collections.namedtuple(
-    'CAdditionExpression',
-    [
-        'left',
-        'right',
-    ],
-)
-
-CSubtractionExpression = collections.namedtuple(
-    'CSubtractionExpression',
-    [
-        'left',
-        'right',
-    ],
-)
-
-CMultiplicationExpression = collections.namedtuple(
-    'CMultiplicationExpression',
-    [
-        'left',
-        'right',
-    ],
-)
-
-CIntegerDivisionExpression = collections.namedtuple(
-    'CIntegerDivisionExpression',
-    [
-        'left',
-        'right',
-    ],
-)
-
-CEqualityExpression = collections.namedtuple(
-    'CEqualityExpression',
-    [
-        'left',
-        'right',
-    ],
-)
-
-CInequalityExpression = collections.namedtuple(
-    'CInequalityExpression',
-    [
-        'left',
-        'right',
-    ],
-)
-
-CGreaterThanOrEqualExpression = collections.namedtuple(
-    'CGreaterThanOrEqualExpression',
-    [
-        'left',
-        'right',
-    ],
-)
-
-CLessThanOrEqualExpression = collections.namedtuple(
-    'CLessThanOrEqualExpression',
-    [
-        'left',
-        'right',
-    ],
-)
-
-CGreaterThanExpression = collections.namedtuple(
-    'CGreaterThanExpression',
-    [
-        'left',
-        'right',
-    ],
-)
-
-CLessThanExpression = collections.namedtuple(
-    'CLessThanExpression',
+CFunctionCallForFurInfixOperator = collections.namedtuple(
+    'CFunctionCallForFurInfixOperator',
     [
+        'name',
         'left',
         'right',
     ],
 )
 
-CAndExpression = collections.namedtuple(
-    'CAndExpression',
+CFunctionCallExpression = collections.namedtuple(
+    'CFunctionCallExpression',
     [
-        'left',
-        'right',
+        'name',
+        'arguments',
     ],
 )
 
-CModularDivisionExpression = collections.namedtuple(
-    'CModularDivisionExpression',
+CSymbolAssignmentStatement = collections.namedtuple(
+    'CSymbolAssignmentStatement',
     [
-        'left',
-        'right',
+        'target',
+        'target_symbol_list_index',
+        'expression',
     ],
 )
 
-CFunctionCallExpression = collections.namedtuple(
-    'CFunctionCallExpression',
+CVariableAssignmentStatement = collections.namedtuple(
+    'CVariableAssignmentStatement',
     [
-        'name',
-        'arguments',
+        'variable',
+        'expression',
     ],
 )
 
-CAssignmentStatement = collections.namedtuple(
-    'CAssignmentStatement',
+CExpressionStatement = collections.namedtuple(
+    'CExpressionStatement',
     [
-        'target',
-        'target_symbol_list_index',
         'expression',
     ],
 )
@@ -154,51 +91,53 @@ CAssignmentStatement = collections.namedtuple(
 CProgram = collections.namedtuple(
     'CProgram',
     [
-        'builtins',
+        'builtin_set',
         'statements',
         'standard_libraries',
+        'string_literal_list',
         'symbol_list',
     ],
 )
 
-EQUALITY_LEVEL_OPERATOR_MAPPING = {
-    '==':   CEqualityExpression,
-    '!=':   CInequalityExpression,
-    '<=':   CLessThanOrEqualExpression,
-    '>=':   CGreaterThanOrEqualExpression,
-    '<':    CLessThanExpression,
-    '>':    CGreaterThanExpression,
+EQUALITY_LEVEL_OPERATOR_TO_FUNCTION_NAME_MAPPING = {
+    '==':   'equals',
+    '!=':   'notEquals',
+    '<=':   'lessThanOrEqual',
+    '>=':   'greaterThanOrEqual',
+    '<':    'lessThan',
+    '>':    'greaterThan',
 }
 
-def transform_equality_level_expression(builtin_dependencies, symbol_list, expression):
+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.FurEqualityLevelExpression):
-        left = transform_equality_level_expression(
-            builtin_dependencies,
-            symbol_list,
+    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(
-            builtin_dependencies,
-            symbol_list,
+            accumulators,
             expression.right,
         )
 
         # TODO Don't evaluate the middle expression twice
-        return CAndExpression(
+        return CFunctionCallForFurInfixOperator(
+            name='and',
             left=left,
-            right=EQUALITY_LEVEL_OPERATOR_MAPPING[expression.operator](
+            right=CFunctionCallForFurInfixOperator(
+                name=EQUALITY_LEVEL_OPERATOR_TO_FUNCTION_NAME_MAPPING[expression.operator],
                 left=middle,
                 right=right,
             ),
         )
 
-    return EQUALITY_LEVEL_OPERATOR_MAPPING[expression.operator](
-        left=transform_expression(builtin_dependencies, symbol_list, expression.left),
-        right=transform_expression(builtin_dependencies, symbol_list, expression.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 = {
@@ -208,112 +147,169 @@ BUILTINS = {
     'true':     [],
 }
 
-def transform_expression(builtin_dependencies, symbol_list, expression):
+def transform_variable_expression(accumulators, expression):
+    return CVariableExpression(variable=expression.variable)
+
+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_expression(accumulators, expression):
     if isinstance(expression, parsing.FurParenthesizedExpression):
         # Parentheses can be removed because everything in the C output is explicitly parenthesized
-        return transform_expression(builtin_dependencies, symbol_list, expression.internal)
+        return transform_expression(accumulators, expression.internal)
 
     if isinstance(expression, parsing.FurNegationExpression):
-        return transform_negation_expression(builtin_dependencies, symbol_list, expression)
+        return transform_negation_expression(accumulators, expression)
 
     if isinstance(expression, parsing.FurFunctionCallExpression):
-        return transform_function_call_expression(builtin_dependencies, symbol_list, expression)
+        return transform_function_call_expression(accumulators, expression)
 
     if isinstance(expression, parsing.FurSymbolExpression):
         if expression.value in ['true', 'false']:
             return CConstantExpression(value=expression.value)
 
-        if expression.value not in symbol_list:
+        if expression.value not in accumulators.symbol_list:
             symbol_list.append(expression.value)
 
         return CSymbolExpression(
             symbol=expression.value,
-            symbol_list_index=symbol_list.index(expression.value),
+            symbol_list_index=accumulators.symbol_list.index(expression.value),
         )
 
+    if isinstance(expression, parsing.FurStringLiteralExpression):
+        value = expression.value
+
+        try:
+            index = accumulators.string_literal_list.index(value)
+        except ValueError:
+            index = len(accumulators.string_literal_list)
+            accumulators.string_literal_list.append(value)
+
+        return CStringLiteral(index=index, value=value)
+
     LITERAL_TYPE_MAPPING = {
         parsing.FurIntegerLiteralExpression: CIntegerLiteral,
-        parsing.FurStringLiteralExpression: CStringLiteral,
     }
 
     if type(expression) in LITERAL_TYPE_MAPPING:
         return LITERAL_TYPE_MAPPING[type(expression)](value=expression.value)
 
-    if isinstance(expression, parsing.FurEqualityLevelExpression):
-        return transform_equality_level_expression(builtin_dependencies, symbol_list, expression)
-
-    INFIX_OPERATOR_TO_TYPE_MAPPING = {
-        '+': CAdditionExpression,
-        '-': CSubtractionExpression,
-        '*': CMultiplicationExpression,
-        '//': CIntegerDivisionExpression,
-        '%': CModularDivisionExpression,
-    }
-
-    return INFIX_OPERATOR_TO_TYPE_MAPPING[expression.operator](
-        left=transform_expression(builtin_dependencies, symbol_list, expression.left),
-        right=transform_expression(builtin_dependencies, symbol_list, expression.right),
-    )
+    # TODO Handle all possible types in this form
+    return {
+        parsing.FurInfixExpression: transform_infix_expression, # TODO Shouldn't need this
+        normalization.NormalFunctionCallExpression: transform_function_call_expression,
+        normalization.NormalInfixExpression: transform_infix_expression,
+        normalization.NormalVariableExpression: transform_variable_expression,
+    }[type(expression)](accumulators, expression)
 
-def transform_assignment_statement(builtin_dependencies, symbol_list, assignment_statement):
+def transform_symbol_assignment_statement(accumulators, assignment_statement):
     # TODO Check that target is not a builtin
-    if assignment_statement.target not in symbol_list:
-        symbol_list.append(assignment_statement.target)
+    if assignment_statement.target not in accumulators.symbol_list:
+        accumulators.symbol_list.append(assignment_statement.target)
 
-    return CAssignmentStatement(
+    return CSymbolAssignmentStatement(
         target=assignment_statement.target,
-        target_symbol_list_index=symbol_list.index(assignment_statement.target),
+        target_symbol_list_index=accumulators.symbol_list.index(assignment_statement.target),
         expression=transform_expression(
-            builtin_dependencies,
-            symbol_list,
+            accumulators,
             assignment_statement.expression,
         ),
     )
 
-def transform_negation_expression(builtin_dependencies, symbol_list, negation_expression):
+def transform_negation_expression(accumulators, negation_expression):
     return CNegationExpression(
-        value=transform_expression(builtin_dependencies, symbol_list, negation_expression.value),
+        value=transform_expression(accumulators, negation_expression.value),
     )
 
-def transform_function_call_expression(builtin_dependencies, symbol_list, function_call):
+def transform_function_call_expression(accumulators, function_call):
+    # TODO Function should be a full expression
     if function_call.function.value in BUILTINS.keys():
         # TODO Check that the builtin is actually callable
-        builtin_dependencies.add(function_call.function.value)
+        accumulators.builtin_set.add(function_call.function.value)
 
         return CFunctionCallExpression(
             name='builtin$' + function_call.function.value,
             arguments=tuple(
-                transform_expression(builtin_dependencies, symbol_list, arg)
+                transform_expression(accumulators, arg)
                 for arg in function_call.arguments
             ),
         )
 
     raise Exception()
 
-def transform_statement(builtin_dependencies, symbol_list, statement):
-    return {
-        parsing.FurAssignmentStatement: transform_assignment_statement,
+def transform_expression_statement(accumulators, statement):
+    expression = {
         parsing.FurFunctionCallExpression: transform_function_call_expression,
-    }[type(statement)](builtin_dependencies, symbol_list, statement)
+        normalization.NormalFunctionCallExpression: transform_function_call_expression,
+    }[type(statement.expression)](accumulators, statement.expression)
+
+    return CExpressionStatement(
+        expression=expression,
+    )
+
+def transform_variable_assignment_statement(accumulators, statement):
+    return CVariableAssignmentStatement(
+        variable=statement.variable,
+        expression=transform_expression(accumulators, statement.expression),
+    )
+
+def transform_statement(accumulators, statement):
+    return {
+        parsing.FurAssignmentStatement: transform_symbol_assignment_statement,
+        parsing.FurExpressionStatement: transform_expression_statement,
+        normalization.NormalVariableAssignmentStatement: transform_variable_assignment_statement,
+        normalization.NormalExpressionStatement: transform_expression_statement,
+    }[type(statement)](accumulators, statement)
+
+
+Accumulators = collections.namedtuple(
+    'Accumulators',
+    [
+        'builtin_set',
+        'symbol_list',
+        'string_literal_list',
+    ],
+)
 
 def transform(program):
-    builtins = set()
-    symbol_list = []
+    accumulators = Accumulators(
+        builtin_set=set(),
+        symbol_list=[],
+        string_literal_list=[],
+    )
 
-    c_statements = [
-        transform_statement(builtins, symbol_list, statement) for statement in program.statement_list
+    statement_list = [
+        transform_statement(accumulators, statement) for statement in program.statement_list
     ]
 
-    standard_libraries = set()
-    for builtin in builtins:
+    standard_library_set = set()
+    for builtin in accumulators.builtin_set:
         for standard_library in BUILTINS[builtin]:
-            standard_libraries.add(standard_library)
+            standard_library_set.add(standard_library)
 
     return CProgram(
-        builtins=builtins,
-        statements=c_statements,
-        standard_libraries=standard_libraries,
-        symbol_list=symbol_list,
+        builtin_set=accumulators.builtin_set,
+        statements=statement_list,
+        standard_libraries=standard_library_set,
+        string_literal_list=accumulators.string_literal_list,
+        symbol_list=accumulators.symbol_list,
     )