Syntax checking/Parser

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Important Classes/Files

eiffel.y

• Eiffel grammar description.
• use geyacc to generate eiffel_parser.e from this file

EIFFEL_PARSER

• inherits from EIFFEL_PARSER_SKELETON (where the features parse, parse_string, make_with_factory are implemented)
• make_with_factory (a_factory: AST_FACTORY): give argument of type AST_NULL_FACTORY (inherits from AST_FACTORY)
• parse (a_file: KL_BINARY_INPUT_FILE) and parse_from_string (a_string: STRING): Both save the results in match_list: LEAF_AS_LIST.

CLASS_AS

• AST of a class

ERROR

• deferred; superclass of all error types like EIFFEL_ERROR or SYNTAX_ERROR
• features line, column: INTEGER give location of error

ERROR_HANDLER

• feature error_list: ERROR is a list of errors found by the parser

SHARED_ERROR_HANDLER

• singleton used by all relevant classes

EIFFEL_CLASS_C

• features build_ast and parse_ast show how the parser can be used.

Implementation

• based on Paul's code

ERROR classes

• Create new SYNTAX_ERROR classes that correspond to Paul's classes, but fit into the current hierarchy
• store start and end position of the error

extend parser to generate the right ERRORs

• Integrate Paul's changes to eiffel.l and eiffel.y into the current versions.
• add facilities from Paul's EIFFEL_PARSER_ERROR_REPORTER
  • in existing class like EIFFEL_PARSER_SKELETON (EP_ERROR_REPORTER only inherits SHARED_ERROR_HANDLER and so does EP_SKELETON
  • in new class

Work distribution in eiffel.y

• Ueli: 0 - 844: before Parent_List
• Marko: 845 - 1494 Formal Generics
• Michi: 1495 - 2130 Instruction Call
• Martin: 2131 - end