LMNO is an LALR(1) parser generator for C or C++. It does the same job as Bison and Yacc. But lmno is not another Yacc clone. It uses a different grammar syntax which is designed to reduce the number of coding errors. LMNO also uses a more sophisticated parsing engine that is faster than Yacc and Bison, and which is both reentrant and thread-safe. Furthermore, LMNO implements features that can be used to eliminate resource leaks, making is suitable for use in long-running programs such as graphical user interfaces or embedded controllers.
For most POSIX type systems, simply cd to the top-level folder and type make && make install. This should work for the vast majority of systems; it has very few build dependencies. There's no autoconf, automake, or other configuration scripts to worry about. The following environment variables may be set to customize the makefile's behavior:
CC=/usr/bin/gcc
CFLAGS=-std=gnu99 -O2
TOUCH=/usr/bin/touch
PREFIX=/usr/local/bin
The behavior of LMNO can be modified using command-line options. You can obtain a list of the available command-line options together with a brief explanation of what each does by typing
lmno -h
As of this writing, the following command-line options are supported:
-b Print only the basis in report.
-C Generate C language parser (the default is a C++ parser).
-c Do not compress the action table.
D=<string> Define an %ifdef macro.
-g Print grammar without actions.
-q (Quiet) Do not print the report file.
-s Print parser stats to standard output.
-v Print version info and exit.
-h Print this help message and exit.
One writes grammar files in a language that is functionally very similar to standard Backus-Nauer Form. You may include inline code to be executed for each reduction, e.g. for building a parse tree, or directly executing interpreted code. Further details can be found in the LMNO wiki.