NAME

       dlg - DFA Lexical Analyzer Generator

SYNTAX

       dlg [options] lexical_spec [output_file]

DESCRIPTION

       dlg  is  a  tool  that produces fast deterministic finite automata for recognizing regular expressions in
       input.

OPTIONS

       -CC    Generate C++ output.  The output_file is not specified in this case.

       -C[ level]
              Where level is the compression level used.  0 indications no compression,  1  removes  all  unused
              characters  from  the  transition  from  table,  and  2  maps  equivalent characters into the same
              character classes.  It is suggested that level -C2 is used, since it will significantly reduce the
              size of the dfa produced for lexical analyzer.

       -m     Produces the header file for the lexical mode with a name other than the default name of "mode.h".

       -i     An interactive, or as interactive as possible, parser is produced.  A character is  only  obtained
              when  required  to  decide  which state to go to.  Some care must be taken to obtain accept states
              that do not require look ahead at the next character to determine if that is the stop state.   Any
              regular  expression with a Kleene closure at the end is guaranteed to require another character of
              look ahead.

       -cl class
              Specify a class name for DLG to generate.  The default is DLGLexer.  "class" will be a subclass of
              DLGLexerBase; only used for -CC.

       -ci    The automaton will treat upper and lower case characters identically.  This is accomplished in the
              automaton; the characters in the lexical buffer are unmodified.

       -cs    Upper and lower case characters are treated as distinct.  This is the default.

       -o dir Directory where output files should go (default=".").  This is very nice for  keeping  the  source
              directory clear of ANTLR and DLG spawn.

       -Wambiguity
              Warns  if  more than one regular expression could match the same character sequence.  The warnings
              give the numbers of the expressions in the dlg lexical specification file.  The numbering  of  the
              expressions starts at one.  Multiple warnings may be print for the same expressions.

       -      Used in place of file names to get input from standard in or send output to standard out.

SPECIAL CONSIDERATIONS

       Dlg  works...   we think.  There is no implicit guarantee of anything.  We reserve no legal rights to the
       software known as the Purdue Compiler Construction Tool Set (PCCTS) — PCCTS is in the public domain.   An
       individual  or  company  may  do  whatever  they wish with source code distributed with PCCTS or the code
       generated by PCCTS, including the incorporation of PCCTS, or its output, into  commercial  software.   We
       encourage  users  to  develop  software  with  PCCTS.   However, we do ask that credit is given to us for
       developing PCCTS.  By "credit", we mean that if you incorporate our source code into one of your programs
       (commercial product, research project, or otherwise) that you acknowledge  this  fact  somewhere  in  the
       documentation, research report, etc...  If you like PCCTS and have developed a nice tool with the output,
       please mention that you developed it using PCCTS.  As long as these guidelines are followed, we expect to
       continue enhancing this system and expect to make other tools available as they are completed.

FILES

       mode.h , dlgauto.h , dlgdef.h

SEE ALSO

       antlr(1), pccts(1)

BUGS

DLG                                                April 1994                                             dlg(1)