Desatomat

Open-source implementation of Desatomat and it's Extended Desátomatu Syntax. This is my effort to reverse-engineer the closed-source Desatomat tool.

This tool aims to cover the features used by the Compile Time Regular Expressions library grammer. It aims to be a drop in replacement.

Setup

To setup you need python and the lark parser

sudo apt install python3 python3-pip
pip3 install lark
git clone https://github.com/alexios-angel/desatomat.git
cd desatomat
chmod +x desatomat

Usage

Basic usage:

./desatomat --input=FILENAME --output=/dev/stdout -q

Option	Description
-q	Only print errors to stdout
--version -v	Print version and exit
--verbose	Set log level to debug
--log	Logs level; Takes debug info warn error and critical as options
--ll	Output LL1 grammer. This option is ignored as it is the default. The original Desatomat uses this option.
--q	Create Q-grammer. This option is ignored as it is the default. The original Desatomat uses this option.
--input	Input grammer file. Use --input=- if you are passing grammer via stdin
--output	Output directory or file. If not a filename --cfg:fname is used; Default directory is the current directory
--cfg:fname	Filename for the output. If not specified grammer.hpp is used.
--cfg:namespace	C++ namespace to put the grammer in
--cfg:guard	C++ header guard to use #ifndef GUARDNAME #define GUARDNAME
--cfg:grammar_name	C++ grammar struct name

Unsupported features

• sigma- is not supported as it is not used in CTRE. I also don't know what it does.
  • sigma- is correctly parsed, but is ignored in this Desatomat and the set is treated as a regular set.
• NAME: rule - NAME is ignored. It seems NAME is only there for debugging.