1plex(1)                Pascal lexical analyzer generator               plex(1)
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NAME

6       plex - The Pascal Lex lexical analyzer generator.
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USAGE

11       lex [options] lex-file[.l] [output-file[.pas]]
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OPTIONS

16       -v     Verbose:  Lex  generates a readable description of the generated
17              lexical analyzer, written to lex-file with new extension .lst
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19       -o     Optimize: Lex optimizes DFA tables to produce a minimal DFA.
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DESCRIPTION

23       TP Lex is a program generator that is used to generate the Turbo Pascal
24       source code for a lexical analyzer subroutine from the specification of
25       an input language by a regular expression grammar.
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27       TP Lex parses the source grammar contained in  lex-file  (with  default
28       suffix  output-file  (with  default  suffix .pas); if no output file is
29       specified, output goes to lex-file with new suffix .pas. If any  errors
30       are  found  during  compilation, error messages are written to the list
31       file (lex-file with new suffix .lst).
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33       The generated output file contains a lexical analyzer  routine,  yylex,
34       implemented as:
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36                function yylex : Integer;
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38       This routine has to be called by your main program to execute the lexi‐
39       cal analyzer. The return value of the yylex routine usually denotes the
40       number  of  a  token recognized by the lexical analyzer (see the return
41       routine in the LexLib unit). At end-of-file the yylex routine  normally
42       returns 0.
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44       The  code  template for the yylex routine may be found in the yylex.cod
45       file. This file is needed by TP Lex when it constructs the output file.
46       It  must be present either in the current directory or in the directory
47       from which TP Lex was executed (TP Lex searches  these  directories  in
48       the  indicated order). (NB: For the Linux/Free Pascal version, the code
49       template is searched in some directory defined at compile-time  instead
50       of the execution path, usually /usr/lib/fpc/lexyacc.)
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52       The TP Lex library (LexLib) unit is required by programs using Lex-gen‐
53       erated lexical analyzers; you will therefore have to put an appropriate
54       uses  clause  into  your program or unit that contains the lexical ana‐
55       lyzer routine. The LexLib unit also  provides  various  useful  utility
56       routines; see the file lexlib.pas for further information.
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MORE INFORMATION

61       For  more information, see the documentation that comes with TP lex and
62       yacc.
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AUTHOR

66       Albert  Graeff   (<ag@muwiinfa.geschichte.uni-mainz.de>,   <Dr.Graef@t-
67       online.de>)
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SEE ALSO

71       ppc386(1) pyacc(1)
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75Free Pascal                       10 Jan 2000                          plex(1)
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