| yacctogold YACC-File [GOLD-File] [Options] |
This utility program will convert a grammar written using the YACC Meta-language to the GOLD Meta-language. The program will create the "hidden" rules that are implied with the %left and %right YACC directives. The %prec directive, which is primarily used for unary operators, is also supported.
Currently, all other YACC directives such as embedded code, %union, %type, etc... are parsed by this utility program, but are discarded.
One of the oldest and most respected parsing engine generators available to developers is YACC. Like "vi" "grep" and "awk", this software is considered the de facto standard in the UNIX world. YACC, which is an acronym for Yet Another Compiler-Compiler, was developed by Stephen C. Johnson at AT&T
YACC can be used to create parsers using the C and C++ programming languages.
The term "YACC" actually refers to two separate compiler-compilers, "lex" and "yacc", which constitute the development platform. Each application is used to generate a different part of the parsing system and, in turn, use different input files with the same generic format, but varying semantics.
The "lex" application generates a new program called "lex.yy.c" which implements the lexer using a Deterministic Finite Automaton. The other application, "yacc", generates a new program called "y.tab.c" which implements a LALR parsing algorithm. Once each application has created their respective program, both can be combined to create the complete system.
| Field | Values | Description |
| Options | -verbose, +verbose |
If this flag is set to true, the program will output progress text to the screen as well as error messages. If set to false, no output will be generated. It defaults to true. |
| -uniform, +uniform |
If this flag is set to true, each production will be indented the same number of spaces from left hand margin. This format makes large grammars much easier to read. If set to false, the width of the rule's name will be used to indent each of the productions. This was the original format used by the GOLD Meta-Language. For small grammars, this format is ideal. The style you select has no effect how the grammar is interpreted by the Builder. By default, this flag is set to true. |
|
| -underscores, +underscores |
In YACC, rule names follow the same syntax
as C++ identifiers. Often they include underscores or compound words. Examples include:
stmt_list, stmtList, and STMT_LIST. If this this flag is set to true, the system will convert all underscores to spaces. The default value is true. |
|
| -case, +case |
In many cases, the YACC grammar will use a change in typecase to represent new words. This is common in most programming languages. If this option is set to true, a space will be inserted whenever the typecase changes. The default value is true. | |
| YACC-File | Required. This file contains the grammar written in the YACC Meta-language | |
| GOLD-File | Optional. This file will be created by the utility program. . |