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

   1 import collections
   2
   3 import parsing
   4 import util
   5
   6 NormalVariableExpression = collections.namedtuple(
   7     'NormalVariableExpression',
   8     [
   9         'variable',
  10     ],
  11 )
  12
  13 NormalNegationExpression = collections.namedtuple(
  14     'NormalNegationExpression',
  15     [
  16         'internal_expression',
  17     ],
  18 )
  19
  20 NormalInfixExpression = collections.namedtuple(
  21     'NormalInfixExpression',
  22     [
  23         'order',
  24         'operator',
  25         'left',
  26         'right',
  27     ],
  28 )
  29
  30 NormalFunctionCallExpression = collections.namedtuple(
  31     'NormalFunctionCallExpression',
  32     [
  33         'function',
  34         'argument_count',
  35         'argument_items',
  36     ],
  37 )
  38
  39 NormalArrayVariableInitializationStatement = collections.namedtuple(
  40     'NormalArrayVariableInitializationStatement',
  41     [
  42         'variable',
  43         'items',
  44     ],
  45 )
  46
  47 NormalVariableInitializationStatement = collections.namedtuple(
  48     'NormalVariableInitializationStatement',
  49     [
  50         'variable',
  51         'expression',
  52     ],
  53 )
  54
  55 NormalVariableReassignmentStatement = collections.namedtuple(
  56     'NormalVariableReassignmentStatement',
  57     [
  58         'variable',
  59         'expression',
  60     ],
  61 )
  62
  63 NormalExpressionStatement = collections.namedtuple(
  64     'NormalExpressionStatement',
  65     [
  66         'expression',
  67     ],
  68 )
  69
  70 NormalAssignmentStatement = collections.namedtuple(
  71     'NormalAssignmentStatement',
  72     [
  73         'target',
  74         'expression',
  75     ],
  76 )
  77
  78 NormalIfElseStatement = collections.namedtuple(
  79     'NormalIfElseStatement',
  80     [
  81         'condition_expression',
  82         'if_statements',
  83         'else_statements',
  84     ],
  85 )
  86
  87 NormalFunctionDefinitionStatement = collections.namedtuple(
  88     'NormalFunctionDefinitionStatement',
  89     [
  90         'name',
  91         'argument_name_list',
  92         'statement_list',
  93     ],
  94 )
  95
  96 NormalProgram = collections.namedtuple(
  97     'NormalProgram',
  98     [
  99         'statement_list',
 100     ],
 101 )
 102
 103 # TODO Get rid of this
 104 def fake_normalization(counter, thing):
 105     return (counter, (), thing)
 106
 107 def normalize_function_call_expression(counter, expression):
 108     assert isinstance(expression, parsing.FurFunctionCallExpression)
 109
 110     prestatements = []
 111     arguments = []
 112
 113     for argument in expression.arguments:
 114         counter, argument_prestatements, normalized_argument = normalize_expression(counter, argument)
 115
 116         for s in argument_prestatements:
 117             prestatements.append(s)
 118
 119         variable = '${}'.format(counter)
 120         prestatements.append(NormalVariableInitializationStatement(
 121             variable=variable,
 122             expression=normalized_argument,
 123         ))
 124         arguments.append(NormalVariableExpression(
 125             variable=variable,
 126         ))
 127         counter += 1
 128
 129     arguments_variable = '${}'.format(counter)
 130     counter += 1
 131
 132     prestatements.append(NormalArrayVariableInitializationStatement(
 133         variable=arguments_variable,
 134         items=tuple(arguments),
 135     ))
 136
 137     return (
 138         counter,
 139         tuple(prestatements),
 140         NormalFunctionCallExpression(
 141             function=expression.function, # TODO Normalize the function
 142             argument_count=len(arguments),
 143             argument_items=NormalVariableExpression(variable=arguments_variable),
 144         ),
 145     )
 146
 147 def normalize_basic_infix_operation(counter, expression):
 148     counter, left_prestatements, left_expression = normalize_expression(counter, expression.left)
 149     counter, right_prestatements, right_expression = normalize_expression(counter, expression.right)
 150
 151     left_variable = '${}'.format(counter)
 152     counter += 1
 153     right_variable = '${}'.format(counter)
 154     counter += 1
 155
 156     root_prestatements = (
 157         NormalVariableInitializationStatement(
 158             variable=left_variable,
 159             expression=left_expression,
 160         ),
 161         NormalVariableInitializationStatement(
 162             variable=right_variable,
 163             expression=right_expression,
 164         ),
 165     )
 166
 167     return (
 168         counter,
 169         left_prestatements + right_prestatements + root_prestatements,
 170         NormalInfixExpression(
 171             order=expression.order, # TODO Do we need this?
 172             operator=expression.operator,
 173             left=NormalVariableExpression(variable=left_variable),
 174             right=NormalVariableExpression(variable=right_variable),
 175         ),
 176     )
 177
 178 def normalize_comparison_expression(counter, expression):
 179     stack = []
 180
 181     while isinstance(expression.left, parsing.FurInfixExpression) and expression.order == 'comparison_level':
 182         stack.append((expression.operator, expression.order, expression.right))
 183         expression = expression.left
 184
 185     counter, left_prestatements, left_expression = normalize_expression(counter, expression.left)
 186     counter, right_prestatements, right_expression = normalize_expression(counter, expression.right)
 187
 188     left_variable = '${}'.format(counter)
 189     counter += 1
 190     right_variable = '${}'.format(counter)
 191     counter += 1
 192
 193     root_prestatements = (
 194         NormalVariableInitializationStatement(
 195             variable=left_variable,
 196             expression=left_expression,
 197         ),
 198         NormalVariableInitializationStatement(
 199             variable=right_variable,
 200             expression=right_expression,
 201         ),
 202     )
 203
 204     counter, result_prestatements, result_expression = (
 205         counter,
 206         left_prestatements + right_prestatements + root_prestatements,
 207         # TODO Implement short-circuiting
 208         NormalInfixExpression(
 209             order=expression.order, # TODO Do we need this?
 210             operator=expression.operator,
 211             left=NormalVariableExpression(variable=left_variable),
 212             right=NormalVariableExpression(variable=right_variable),
 213         ),
 214     )
 215
 216     while len(stack) > 0:
 217         right_operator, right_order, right_expression = stack.pop()
 218         and_right_expression = parsing.FurInfixExpression(
 219             operator=right_operator,
 220             order=right_order,
 221             left=NormalVariableExpression(variable=right_variable),
 222             right=right_expression,
 223         )
 224
 225         and_expression = parsing.FurInfixExpression(
 226             operator='and',
 227             order='and_level',
 228             left=result_expression,
 229             right=and_right_expression,
 230         )
 231
 232         counter, and_prestatements, result_expression = normalize_boolean_expression(
 233             counter,
 234             and_expression,
 235         )
 236
 237         result_prestatements = result_prestatements + and_prestatements
 238
 239     return (counter, result_prestatements, result_expression)
 240
 241 def normalize_boolean_expression(counter, expression):
 242     counter, left_prestatements, left_expression = normalize_expression(counter, expression.left)
 243     counter, right_prestatements, right_expression = normalize_expression(counter, expression.right)
 244
 245     result_variable = '${}'.format(counter)
 246     if_else_prestatment = NormalVariableInitializationStatement(variable=result_variable, expression=left_expression)
 247     counter += 1
 248
 249     condition_expression=NormalVariableExpression(variable=result_variable)
 250     short_circuited_statements = right_prestatements + (NormalVariableReassignmentStatement(variable=result_variable, expression=right_expression),)
 251
 252     if expression.operator == 'and':
 253         if_else_statement = NormalIfElseStatement(
 254             condition_expression=condition_expression,
 255             if_statements=short_circuited_statements,
 256             else_statements=(),
 257         )
 258
 259     elif expression.operator == 'or':
 260         if_else_statement = NormalIfElseStatement(
 261             condition_expression=condition_expression,
 262             if_statements=(),
 263             else_statements=short_circuited_statements,
 264         )
 265
 266     else:
 267         raise Exception('Unable to handle operator "{}"'.format(expression.operator))
 268
 269     return (
 270         counter,
 271         left_prestatements + (if_else_prestatment, if_else_statement),
 272         NormalVariableExpression(variable=result_variable),
 273     )
 274
 275
 276 def normalize_infix_expression(counter, expression):
 277     return {
 278         'multiplication_level': normalize_basic_infix_operation,
 279         'addition_level': normalize_basic_infix_operation,
 280         'comparison_level': normalize_comparison_expression,
 281         'and_level': normalize_boolean_expression,
 282         'or_level': normalize_boolean_expression,
 283     }[expression.order](counter, expression)
 284
 285 def normalize_negation_expression(counter, expression):
 286     counter, prestatements, internal_expression = normalize_expression(counter, expression.value)
 287
 288     internal_variable = '${}'.format(counter)
 289     counter += 1
 290
 291     return (
 292         counter,
 293         prestatements + (NormalVariableInitializationStatement(variable=internal_variable, expression=internal_expression),),
 294         NormalNegationExpression(internal_expression=NormalVariableExpression(variable=internal_variable)),
 295     )
 296
 297 def normalize_parenthesized_expression(counter, expression):
 298     return normalize_expression(counter, expression.internal)
 299
 300 def normalize_expression(counter, expression):
 301     return {
 302         NormalInfixExpression: fake_normalization,
 303         NormalVariableExpression: fake_normalization,
 304         parsing.FurFunctionCallExpression: normalize_function_call_expression,
 305         parsing.FurInfixExpression: normalize_infix_expression,
 306         parsing.FurIntegerLiteralExpression: fake_normalization,
 307         parsing.FurNegationExpression: normalize_negation_expression,
 308         parsing.FurParenthesizedExpression: normalize_parenthesized_expression,
 309         parsing.FurStringLiteralExpression: fake_normalization,
 310         parsing.FurSymbolExpression: fake_normalization,
 311     }[type(expression)](counter, expression)
 312
 313 def normalize_expression_statement(counter, statement):
 314     # TODO Verify all expression types are supported and just call normalize_expression
 315     counter, prestatements, normalized = {
 316         parsing.FurFunctionCallExpression: normalize_function_call_expression,
 317         parsing.FurSymbolExpression: normalize_expression,
 318         parsing.FurInfixExpression: normalize_expression,
 319         parsing.FurIntegerLiteralExpression: normalize_expression,
 320     }[type(statement.expression)](counter, statement.expression)
 321
 322     return (
 323         counter,
 324         prestatements,
 325         NormalExpressionStatement(expression=normalized),
 326     )
 327
 328 def normalize_function_definition_statement(counter, statement):
 329     return (
 330         counter,
 331         (),
 332         NormalFunctionDefinitionStatement(
 333             name=statement.name,
 334             argument_name_list=statement.argument_name_list,
 335             statement_list=normalize_statement_list(statement.statement_list),
 336         ),
 337     )
 338
 339 def normalize_assignment_statement(counter, statement):
 340     counter, prestatements, normalized_expression = normalize_expression(counter, statement.expression)
 341     return (
 342         counter,
 343         prestatements,
 344         NormalAssignmentStatement(
 345             target=statement.target,
 346             expression=normalized_expression,
 347         ),
 348     )
 349
 350 def normalize_statement(counter, statement):
 351     return {
 352         parsing.FurAssignmentStatement: normalize_assignment_statement,
 353         parsing.FurExpressionStatement: normalize_expression_statement,
 354         parsing.FurFunctionDefinitionStatement: normalize_function_definition_statement,
 355     }[type(statement)](counter, statement)
 356
 357 @util.force_generator(tuple)
 358 def normalize_statement_list(statement_list):
 359     counter = 0
 360
 361     for statement in statement_list:
 362         counter, prestatements, normalized = normalize_statement(counter, statement)
 363         for s in prestatements:
 364             yield s
 365         yield normalized
 366
 367 def normalize(program):
 368
 369     return NormalProgram(
 370         statement_list=normalize_statement_list(program.statement_list),
 371     )