+def symbol_expression_pair_parser(index, tokens):
+ failure = (False, index, None)
+
+ if tokens[index].type == 'symbol':
+ symbol = tokens[index].match
+ index += 1
+ else:
+ return failure
+
+ if tokens[index].type == 'colon':
+ index += 1
+ else:
+ return failure
+
+ success, index, expression = _expression_parser(index, tokens)
+
+ if not success:
+ raise Exception()
+
+ return (
+ True,
+ index,
+ FurSymbolExpressionPair(
+ symbol=symbol,
+ expression=expression,
+ ),
+ )
+
+def _structure_literal_parser(index, tokens):
+ success, index, result = _parenthese_wrapped_parser(_comma_separated_list_parser(symbol_expression_pair_parser))(index, tokens)
+ return (
+ success,
+ index,
+ FurStructureLiteralExpression(
+ fields=result,
+ ),
+ )
+
+def _lambda_expression_parser(index, tokens):
+ failure = (False, index, None)
+
+ if tokens[index].type == 'keyword' and tokens[index].match == 'lambda':
+ index += 1
+ else:
+ return failure
+
+ if tokens[index].type == 'open_parenthese':
+ index += 1
+ else:
+ raise Exception('Expected "(", found "{}" on line {}'.format(
+ tokens[index].match,
+ tokens[index].metadata.line,
+ ))
+
+ success, index, argument_name_list = _comma_separated_list_parser(_symbol_expression_parser)(
+ index,
+ tokens,
+ )
+
+ if tokens[index].type == 'close_parenthese':
+ index += 1
+ else:
+ raise Exception('Expected ")", found "{}" on line {}'.format(
+ tokens[index].match,
+ tokens[index].line,
+ ))
+
+ if tokens[index].match == 'do':
+ index += 1
+ else:
+ return failure
+
+ success, index, statement_list = _zero_or_more_parser(tuple, _statement_parser)(index, tokens)
+
+ _, index, _ = consume_newlines(index, tokens)
+
+ if tokens[index].type == 'keyword' and tokens[index].match == 'end':
+ index += 1
+ else:
+ return failure
+
+ return True, index, FurLambdaExpression(
+ argument_name_list=tuple(an.symbol for an in argument_name_list),
+ statement_list=statement_list,
+ )
+
+
+