


dlg - DFA Lexical Analyzer Generator


dlg [options] lexical_spec [output_file]

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


-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  char-
     acter  classes.  It is suggested that level -C2 is used, since it
     will significantly reduce the size of the dfa produced for  lexi-
     cal 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  pro-
     duced.   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.

-ci  The automaton will treat upper and lower case characters  identi-
     cally.   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 dirDirectory 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 expres-
     sions 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



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                                                                 PCCTS


     output to standard out.


     Dlg works...  we think.  There is no implicit guarantee  of  any-
thing.  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.   How-
ever,  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 con-
tinue enhancing this system and expect to make other  tools  available
as they are completed.

mode.h , dlgauto.h , dlgdef.h




































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