code.kerkeslager.com Git - fur/blob - desugaring.py

   1 import collections
   2
   3 import parsing
   4
   5 DesugaredFunctionCallExpression = collections.namedtuple(
   6     'DesugaredFunctionCallExpression',
   7     (
   8         'metadata',
   9         'function',
  10         'argument_list',
  11     ),
  12 )
  13
  14 DesugaredIfExpression = collections.namedtuple(
  15     'DesugaredIfExpression',
  16     (
  17         'condition_expression',
  18         'if_statement_list',
  19         'else_statement_list',
  20     ),
  21 )
  22
  23 DesugaredIntegerLiteralExpression = collections.namedtuple(
  24     'DesugaredIntegerLiteralExpression',
  25     (
  26         'integer',
  27     ),
  28 )
  29
  30 DesugaredLambdaExpression = collections.namedtuple(
  31     'DesugaredLambdaExpression',
  32     (
  33         'argument_name_list',
  34         'statement_list',
  35     ),
  36 )
  37
  38 DesugaredListLiteralExpression = collections.namedtuple(
  39     'DesugaredListLiteralExpression',
  40     (
  41         'item_expression_list',
  42     ),
  43 )
  44
  45 DesugaredStringLiteralExpression = collections.namedtuple(
  46     'DesugaredStringLiteralExpression',
  47     (
  48         'string',
  49     ),
  50 )
  51
  52 DesugaredSymbolExpressionPair = collections.namedtuple(
  53     'DesugaredSymbolExpressionPair',
  54     (
  55         'symbol',
  56         'expression',
  57     ),
  58 )
  59
  60 DesugaredStructureLiteralExpression = collections.namedtuple(
  61     'DesugaredStructureLiteralExpression',
  62     (
  63         'fields',
  64     ),
  65 )
  66
  67 DesugaredSymbolExpression = collections.namedtuple(
  68     'DesugaredSymbolExpression',
  69     (
  70         'metadata',
  71         'symbol',
  72     ),
  73 )
  74
  75 DesugaredAssignmentStatement = collections.namedtuple(
  76     'DesugaredAssignmentStatement',
  77     (
  78         'target',
  79         'expression',
  80     ),
  81 )
  82
  83 DesugaredExpressionStatement = collections.namedtuple(
  84     'DesugaredExpressionStatement',
  85     (
  86         'expression',
  87     ),
  88 )
  89
  90 DesugaredFunctionDefinitionStatement = collections.namedtuple(
  91     'DesugaredFunctionDefinitionStatement',
  92     (
  93         'name',
  94         'argument_name_list',
  95         'statement_list',
  96     ),
  97 )
  98
  99 DesugaredProgram = collections.namedtuple(
 100     'DesugaredProgram',
 101     (
 102         'statement_list',
 103     ),
 104 )
 105
 106 def desugar_function_call_expression(expression):
 107     return DesugaredFunctionCallExpression(
 108         metadata=expression.metadata,
 109         function=desugar_expression(expression.function),
 110         argument_list=tuple(desugar_expression(e) for e in expression.arguments),
 111     )
 112
 113 def desugar_if_expression(expression):
 114     return DesugaredIfExpression(
 115         condition_expression=desugar_expression(expression.condition_expression),
 116         if_statement_list=tuple(desugar_statement(s) for s in expression.if_statement_list),
 117         else_statement_list=tuple(desugar_statement(s) for s in expression.else_statement_list),
 118     )
 119
 120 def desugar_infix_expression(expression):
 121     if expression.operator == 'and':
 122         return DesugaredIfExpression(
 123             condition_expression=desugar_expression(expression.left),
 124             if_statement_list=(
 125                 DesugaredExpressionStatement(expression=desugar_expression(expression.right)),
 126             ),
 127             else_statement_list=(
 128                 DesugaredExpressionStatement(
 129                     expression=DesugaredSymbolExpression(
 130                         metadata=expression.metadata,
 131                         symbol='false',
 132                     ),
 133                 ),
 134             ),
 135         )
 136
 137     if expression.operator == 'or':
 138         return DesugaredIfExpression(
 139             condition_expression=desugar_expression(expression.left),
 140             if_statement_list=(
 141                 DesugaredExpressionStatement(
 142                     expression=DesugaredSymbolExpression(
 143                         metadata=expression.metadata,
 144                         symbol='true',
 145                     ),
 146                 ),
 147             ),
 148             else_statement_list=(
 149                 DesugaredExpressionStatement(expression=desugar_expression(expression.right)),
 150             ),
 151         )
 152
 153     if expression.operator == '.':
 154         return DesugaredFunctionCallExpression(
 155             metadata=expression.metadata,
 156             function=DesugaredSymbolExpression(
 157                 metadata=expression.metadata,
 158                 symbol='__field__',
 159             ),
 160             argument_list=(
 161                 desugar_expression(expression.left),
 162                 DesugaredStringLiteralExpression(string=expression.right.symbol),
 163             ),
 164         )
 165
 166     function = {
 167         '++': '__concat__',
 168         '+': '__add__',
 169         '-': '__subtract__',
 170         '*': '__multiply__',
 171         '//': '__integer_divide__',
 172         '%': '__modular_divide__',
 173         '<': '__lt__',
 174         '>': '__gt__',
 175         '<=': '__lte__',
 176         '>=': '__gte__',
 177         '==': '__eq__',
 178         '!=': '__neq__',
 179     }[expression.operator]
 180
 181     return DesugaredFunctionCallExpression(
 182         metadata=expression.metadata,
 183         function=DesugaredSymbolExpression(
 184             metadata=expression.metadata,
 185             symbol=function,
 186         ),
 187         argument_list=(
 188             desugar_expression(expression.left),
 189             desugar_expression(expression.right),
 190         ),
 191     )
 192
 193 def desugar_integer_literal_expression(expression):
 194     return DesugaredIntegerLiteralExpression(
 195         integer=expression.integer,
 196     )
 197
 198 def desugar_lambda_expression(expression):
 199     return DesugaredLambdaExpression(
 200         argument_name_list=expression.argument_name_list,
 201         statement_list=tuple(desugar_statement(s) for s in expression.statement_list),
 202     )
 203
 204 def desugar_list_item_expression(expression):
 205     return DesugaredFunctionCallExpression(
 206         metadata=expression.metadata,
 207         function=DesugaredSymbolExpression(
 208             metadata=expression.metadata,
 209             symbol='__get__',
 210         ),
 211         argument_list=(
 212             desugar_expression(expression.list_expression),
 213             desugar_expression(expression.index_expression),
 214         ),
 215     )
 216
 217 def desugar_list_literal_expression(expression):
 218     return DesugaredListLiteralExpression(
 219         item_expression_list=tuple(desugar_expression(i) for i in expression.item_expression_list),
 220     )
 221
 222 def desugar_negation_expression(expression):
 223     return DesugaredFunctionCallExpression(
 224         metadata=expression.metadata,
 225         function=DesugaredSymbolExpression(
 226             metadata=expression.metadata,
 227             symbol='__negate__',
 228         ),
 229         argument_list=(
 230             desugar_expression(expression.value),
 231         ),
 232     )
 233
 234 def desugar_string_literal_expression(expression):
 235     return DesugaredStringLiteralExpression(
 236         string=expression.string,
 237     )
 238
 239 def desugar_structure_literal_expression(expression):
 240     return DesugaredStructureLiteralExpression(
 241         fields=tuple(
 242             DesugaredSymbolExpressionPair(
 243                 symbol=p.symbol,
 244                 expression=desugar_expression(p.expression),
 245             ) for p in expression.fields
 246         ),
 247     )
 248
 249 def desugar_symbol_expression(expression):
 250     return DesugaredSymbolExpression(
 251         metadata=expression.metadata,
 252         symbol=expression.symbol,
 253     )
 254
 255 def desugar_expression(expression):
 256     return {
 257         parsing.FurFunctionCallExpression: desugar_function_call_expression,
 258         parsing.FurIfExpression: desugar_if_expression,
 259         parsing.FurInfixExpression: desugar_infix_expression,
 260         parsing.FurIntegerLiteralExpression: desugar_integer_literal_expression,
 261         parsing.FurLambdaExpression: desugar_lambda_expression,
 262         parsing.FurListItemExpression: desugar_list_item_expression,
 263         parsing.FurListLiteralExpression: desugar_list_literal_expression,
 264         parsing.FurNegationExpression: desugar_negation_expression,
 265         parsing.FurStringLiteralExpression: desugar_string_literal_expression,
 266         parsing.FurStructureLiteralExpression: desugar_structure_literal_expression,
 267         parsing.FurSymbolExpression: desugar_symbol_expression,
 268     }[type(expression)](expression)
 269
 270 def desugar_assignment_statement(statement):
 271     return DesugaredAssignmentStatement(
 272         target=statement.target,
 273         expression=desugar_expression(statement.expression),
 274     )
 275
 276 def desugar_expression_statement(statement):
 277     return DesugaredExpressionStatement(
 278         expression=desugar_expression(statement.expression),
 279     )
 280
 281 def desugar_function_definition_statement(statement):
 282     return DesugaredFunctionDefinitionStatement(
 283         name=statement.name,
 284         argument_name_list=statement.argument_name_list,
 285         statement_list=tuple(desugar_statement(s) for s in statement.statement_list),
 286     )
 287
 288 def desugar_statement(statement):
 289     return {
 290         parsing.FurAssignmentStatement: desugar_assignment_statement,
 291         parsing.FurExpressionStatement: desugar_expression_statement,
 292         parsing.FurFunctionDefinitionStatement: desugar_function_definition_statement,
 293     }[type(statement)](statement)
 294
 295 def desugar(program):
 296     return DesugaredProgram(
 297         statement_list=[desugar_statement(s) for s in program.statement_list],
 298     )