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