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 charac-
ters 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 ana-
-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 clo-
sure at the end is guaranteed to require another character of look ahead.
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 keep-
ing the source directory clear of ANTLR and DLG spawn.
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 stan-
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 (com-
mercial 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)