

dlg(1)                  PCCTS Manual Pages                 dlg(1)


NNAAMMEE
       dlg - DFA Lexical Analyzer Generator

SSYYNNTTAAXX
       ddllgg [_o_p_t_i_o_n_s] _l_e_x_i_c_a_l___s_p_e_c [_o_u_t_p_u_t___f_i_l_e]

DDEESSCCRRIIPPTTIIOONN
       ddllgg  is  a  tool  that  produces fast deterministic finite
       automata for recognizing regular expressions in input.

OOPPTTIIOONNSS
       --CCCC    Generate C++ output.  The _o_u_t_p_u_t___f_i_l_e is not speci-
              fied in this case.

       --CC[ lleevveell]
              Where level is the compression level used.  0 indi-
              cations no compression, 1 removes all unused  char-
              acters  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m     Produces  the header file for the lexical mode with
              a name other than the default name of "mode.h".

       --i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.

       --ccll class
              Specify a class name  for  DLG  to  generate.   The
              default is DLGLexer.

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

       --ccss    Upper and lower case characters are treated as dis-
              tinct.  This is the default.

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

       --WWaammbbiigguuiittyy
              Warns  if  more  than  one regular expression could


DLG                         April 1994                          1


dlg(1)                  PCCTS Manual Pages                 dlg(1)


              match the same character  sequence.   The  warnings
              give the numbers of the expressions in the dlg lex-
              ical 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 stan-
              dard in or send output to standard out.

SSPPEECCIIAALL CCOONNSSIIDDEERRAATTIIOONNSS
       _D_l_g works...  we think.  There is no implicit guarantee of
       anything.  We reserve no  lleeggaall  rights  to  the  software
       known as the Purdue Compiler Construction Tool Set (PCCTS)
       -- PCCTS is in the public domain.  An individual  or  com-
       pany  may  do  whatever  they  wish  with source code dis-
       tributed with  PCCTS  or  the  code  generated  by  PCCTS,
       including  the incorporation of PCCTS, or its output, into
       commercial software.  We encourage users to develop  soft-
       ware  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 devel-
       oped  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  com-
       pleted.

FFIILLEESS
       mmooddee..hh , ddllggaauuttoo..hh , ddllggddeeff..hh

SSEEEE AALLSSOO
       aannttllrr(1), ppccccttss(1)

BBUUGGSS


DLG                         April 1994                          2