NAME
pyacc - Pascal Yacc compiler compiler.
USAGE
yacc [options] yacc-file[.y] [output-file[.pas]]
SH OPTIONS
-v Verbose: Pascal Yacc generates a readable description of the
generated parser, written to yacc-file with new extension .lst.
-d Debug: TP Yacc generates a parser with debugging output.
DESCRIPTION
TP Yacc is a program that lets you prepare parsers from the description
of input languages by BNF-like grammars. You simply specify the grammar
for your target language, augmented with the Turbo Pascal code
necessary to process the syntactic constructs, and TP Yacc translates
your grammar into the Turbo Pascal code for a corresponding parser
subroutine named yyparse.
TP Yacc parses the source grammar contained in yacc-file (with default
suffix .y) and writes the constructed parser subroutine to the
specified output-file (with default suffix .pas); if no output file is
specified, output goes to yacc-file with new suffix .pas. If any errors
are found during compilation, error messages are written to the list
file (yacc-file with new suffix .lst).
The generated parser routine, yyparse, is declared as:
function yyparse : Integer;
This routine may be called by your main program to execute the parser.
The return value of the yyparse routine denotes success or failure of
the parser (possible return values: 0 = success, 1 = unrecoverable
syntax error or parse stack overflow).
Similar to TP Lex, the code template for the yyparse routine may be
found in the yyparse.cod file. The rules for locating this file are
analogous to those of TP Lex (see Section ‘TP Lex’).
The TP Yacc library (YaccLib) unit is required by programs using Yacc-
generated parsers; you will therefore have to put an appropriate uses
clause into your program or unit that contains the parser routine. The
YaccLib unit also provides some routines which may be used to control
the actions of the parser. See the file yacclib.pas for further
information.
More information
For more information, see the documentation that comes with TP lex and
yacc.
AUTHOR
Albert Graeff (<ag@muwiinfa.geschichte.uni-mainz.de>, <Dr.Graef@t-
online.de>)
SEE ALSO
ppc386(1) plex(1)