X-Git-Url: https://code.kerkeslager.com/?p=fur;a=blobdiff_plain;f=desugaring.py;h=28d1a7820748b4ae463d1dc2b8aab73e3f47cdd7;hp=ef5163993bfc6266c72cfe9819d3e1ab970723ac;hb=3dc627f8d6b5846081ef8ed15d5546e51d2ecb8d;hpb=cccc042f21a9c90cbd78cbad28288160a5899a33

diff --git a/desugaring.py b/desugaring.py
index ef51639..28d1a78 100644
--- a/desugaring.py
+++ b/desugaring.py
@@ -1,5 +1,108 @@
 import collections
 
+import parsing
+
+DesugaredBuiltinExpression = collections.namedtuple(
+    'DesugaredBuiltinExpression',
+    (
+        'metadata',
+        'symbol',
+    ),
+)
+
+DesugaredFunctionCallExpression = collections.namedtuple(
+    'DesugaredFunctionCallExpression',
+    (
+        'metadata',
+        'function',
+        'argument_list',
+    ),
+)
+
+DesugaredIfExpression = collections.namedtuple(
+    'DesugaredIfExpression',
+    (
+        'condition_expression',
+        'if_statement_list',
+        'else_statement_list',
+    ),
+)
+
+DesugaredIntegerLiteralExpression = collections.namedtuple(
+    'DesugaredIntegerLiteralExpression',
+    (
+        'integer',
+    ),
+)
+
+_DesugaredLambdaExpression = collections.namedtuple(
+    'DesugaredLambdaExpression',
+    (
+        'name',
+        'argument_name_list',
+        'statement_list',
+    ),
+)
+
+class DesugaredLambdaExpression(_DesugaredLambdaExpression):
+    def __new__(cls, *args, **kwargs):
+        if 'name' not in kwargs:
+            kwargs['name'] = None
+
+        return super(DesugaredLambdaExpression, cls).__new__(cls, *args, **kwargs)
+
+DesugaredListLiteralExpression = collections.namedtuple(
+    'DesugaredListLiteralExpression',
+    (
+        'item_expression_list',
+    ),
+)
+
+DesugaredStringLiteralExpression = collections.namedtuple(
+    'DesugaredStringLiteralExpression',
+    (
+        'string',
+    ),
+)
+
+DesugaredSymbolExpressionPair = collections.namedtuple(
+    'DesugaredSymbolExpressionPair',
+    (
+        'symbol',
+        'expression',
+    ),
+)
+
+DesugaredStructureLiteralExpression = collections.namedtuple(
+    'DesugaredStructureLiteralExpression',
+    (
+        'fields',
+    ),
+)
+
+DesugaredSymbolExpression = collections.namedtuple(
+    'DesugaredSymbolExpression',
+    (
+        'metadata',
+        'symbol',
+    ),
+)
+
+DesugaredAssignmentStatement = collections.namedtuple(
+    'DesugaredAssignmentStatement',
+    (
+        'target',
+        'expression',
+    ),
+)
+
+DesugaredExpressionStatement = collections.namedtuple(
+    'DesugaredExpressionStatement',
+    (
+        'expression',
+    ),
+)
+
 DesugaredProgram = collections.namedtuple(
     'DesugaredProgram',
     (
@@ -7,7 +110,199 @@ DesugaredProgram = collections.namedtuple(
     ),
 )
 
+def desugar_function_call_expression(expression):
+    return DesugaredFunctionCallExpression(
+        metadata=expression.metadata,
+        function=desugar_expression(expression.function),
+        argument_list=tuple(desugar_expression(e) for e in expression.arguments),
+    )
+
+def desugar_if_expression(expression):
+    return DesugaredIfExpression(
+        condition_expression=desugar_expression(expression.condition_expression),
+        if_statement_list=tuple(desugar_statement(s) for s in expression.if_statement_list),
+        else_statement_list=tuple(desugar_statement(s) for s in expression.else_statement_list),
+    )
+
+def desugar_infix_expression(expression):
+    if expression.operator == 'and':
+        return DesugaredIfExpression(
+            condition_expression=desugar_expression(expression.left),
+            if_statement_list=(
+                DesugaredExpressionStatement(expression=desugar_expression(expression.right)),
+            ),
+            else_statement_list=(
+                DesugaredExpressionStatement(
+                    expression=DesugaredSymbolExpression(
+                        metadata=expression.metadata,
+                        symbol='false',
+                    ),
+                ),
+            ),
+        )
+
+    if expression.operator == 'or':
+        return DesugaredIfExpression(
+            condition_expression=desugar_expression(expression.left),
+            if_statement_list=(
+                DesugaredExpressionStatement(
+                    expression=DesugaredSymbolExpression(
+                        metadata=expression.metadata,
+                        symbol='true',
+                    ),
+                ),
+            ),
+            else_statement_list=(
+                DesugaredExpressionStatement(expression=desugar_expression(expression.right)),
+            ),
+        )
+
+    if expression.operator == '.':
+        return DesugaredFunctionCallExpression(
+            metadata=expression.metadata,
+            function=DesugaredSymbolExpression(
+                metadata=expression.metadata,
+                symbol='__field__',
+            ),
+            argument_list=(
+                desugar_expression(expression.left),
+                DesugaredStringLiteralExpression(string=expression.right.symbol),
+            ),
+        )
+
+    function = {
+        '++': '__concat__',
+        '+': '__add__',
+        '-': '__subtract__',
+        '*': '__multiply__',
+        '//': '__integer_divide__',
+        '%': '__modular_divide__',
+        '<': '__lt__',
+        '>': '__gt__',
+        '<=': '__lte__',
+        '>=': '__gte__',
+        '==': '__eq__',
+        '!=': '__neq__',
+    }[expression.operator]
+
+    return DesugaredFunctionCallExpression(
+        metadata=expression.metadata,
+        function=DesugaredBuiltinExpression(
+            metadata=expression.metadata,
+            symbol=function,
+        ),
+        argument_list=(
+            desugar_expression(expression.left),
+            desugar_expression(expression.right),
+        ),
+    )
+
+def desugar_integer_literal_expression(expression):
+    return DesugaredIntegerLiteralExpression(
+        integer=expression.integer,
+    )
+
+def desugar_lambda_expression(expression):
+    return DesugaredLambdaExpression(
+        argument_name_list=expression.argument_name_list,
+        statement_list=tuple(desugar_statement(s) for s in expression.statement_list),
+    )
+
+def desugar_list_item_expression(expression):
+    return DesugaredFunctionCallExpression(
+        metadata=expression.metadata,
+        function=DesugaredBuiltinExpression(
+            metadata=expression.metadata,
+            symbol='__get__',
+        ),
+        argument_list=(
+            desugar_expression(expression.list_expression),
+            desugar_expression(expression.index_expression),
+        ),
+    )
+
+def desugar_list_literal_expression(expression):
+    return DesugaredListLiteralExpression(
+        item_expression_list=tuple(desugar_expression(i) for i in expression.item_expression_list),
+    )
+
+def desugar_negation_expression(expression):
+    return DesugaredFunctionCallExpression(
+        metadata=expression.metadata,
+        function=DesugaredBuiltinExpression(
+            metadata=expression.metadata,
+            symbol='__negate__',
+        ),
+        argument_list=(
+            desugar_expression(expression.value),
+        ),
+    )
+
+def desugar_string_literal_expression(expression):
+    return DesugaredStringLiteralExpression(
+        string=expression.string,
+    )
+
+def desugar_structure_literal_expression(expression):
+    return DesugaredStructureLiteralExpression(
+        fields=tuple(
+            DesugaredSymbolExpressionPair(
+                symbol=p.symbol,
+                expression=desugar_expression(p.expression),
+            ) for p in expression.fields
+        ),
+    )
+
+def desugar_symbol_expression(expression):
+    return DesugaredSymbolExpression(
+        metadata=expression.metadata,
+        symbol=expression.symbol,
+    )
+
+def desugar_expression(expression):
+    return {
+        parsing.FurFunctionCallExpression: desugar_function_call_expression,
+        parsing.FurIfExpression: desugar_if_expression,
+        parsing.FurInfixExpression: desugar_infix_expression,
+        parsing.FurIntegerLiteralExpression: desugar_integer_literal_expression,
+        parsing.FurLambdaExpression: desugar_lambda_expression,
+        parsing.FurListItemExpression: desugar_list_item_expression,
+        parsing.FurListLiteralExpression: desugar_list_literal_expression,
+        parsing.FurNegationExpression: desugar_negation_expression,
+        parsing.FurStringLiteralExpression: desugar_string_literal_expression,
+        parsing.FurStructureLiteralExpression: desugar_structure_literal_expression,
+        parsing.FurSymbolExpression: desugar_symbol_expression,
+    }[type(expression)](expression)
+
+def desugar_assignment_statement(statement):
+    return DesugaredAssignmentStatement(
+        target=statement.target,
+        expression=desugar_expression(statement.expression),
+    )
+
+def desugar_expression_statement(statement):
+    return DesugaredExpressionStatement(
+        expression=desugar_expression(statement.expression),
+    )
+
+def desugar_function_definition_statement(statement):
+    return DesugaredAssignmentStatement(
+        target=statement.name,
+        expression=DesugaredLambdaExpression(
+            name=statement.name,
+            argument_name_list=statement.argument_name_list,
+            statement_list=tuple(desugar_statement(s) for s in statement.statement_list),
+        ),
+    )
+
+def desugar_statement(statement):
+    return {
+        parsing.FurAssignmentStatement: desugar_assignment_statement,
+        parsing.FurExpressionStatement: desugar_expression_statement,
+        parsing.FurFunctionDefinitionStatement: desugar_function_definition_statement,
+    }[type(statement)](statement)
+
 def desugar(program):
     return DesugaredProgram(
-        statement_list=program.statement_list,
+        statement_list=[desugar_statement(s) for s in program.statement_list],
     )