dlg(1) PCCTS Manual Pages dlg(1)
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.
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 sig-
nificantly 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
Specify a class name for DLG to generate. The default is DLGLexer.
-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
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
- Used in place of file names to get input from standard in or send output to standard out.
Dlg works... we think. There is no implicit guarantee of anything. We reserve no legal rights to the software known as the Purdue Com-
piler 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.
mode.h , dlgauto.h , dlgdef.h
DLG April 1994 dlg(1)