antlr4-macro

A macro pre-processor for ANTLR4. This project is not yet ready for production-level consumption.

License

This project is licensed under the MIT license.

Usage

You should add pre-build event(s) in your IDE of choice to run the antlr4-macro artifact.

You can specify either target file, i.e. -i my-grammar.mg4 or the entire working directory, i.e. -i ..
You may also enable recursive traversal of the working directory, i.e. -i . -r.
When traversing the directory, only files with extension mg4 will be picked up.

More usage information available at java -jar antlr4-macro.jar -help

How it works

You write your grammars in ANTLR4 syntax, however now you can also add C-like macros to your code, such as #MY_MACRO: 'my macro'; and then use #MY_MACRO elsewhere in your code as an identifier. The scope of the macro rules is the entire current file.

A user-configured pre-build event should then call the executable and thus parse your macro grammar files and outputs valid ANTLR4 grammar files.

Command Line Options

This is a list of all command line options to be implemented:

Option	Argument	Definition
-h -help		Displays all available commands and their descriptions
-url		Prints the current url of the source code
-version		Prints the current version of antlr4-macro
-m -minify		Returns a minified version of grammar
-i -input	. for current working directory, /path/to/dir/ for specific directory, /path/to/file for specific file	Specifies a current working directory, specific directory or a specific file to be processed
-r -recursive		Processes the given directory recursively
-o -out	/path/to/dir/	Specify the directory to store the processed grammar files
-t -threads	<int>	Specify the number of threads to use to parse directory (default 2 threads)
-v -verbose		Print a verbose output to console

Example

Input:

grammar HelloWorld;

/// my macro definitions, this comment will not appear in the output
#HELLO: 'Hello';
#WORLD: 'World';

// parser rules
mySingleRule: HELLOWORLD;

// lexer rules
HELLOWORLD: #HELLO #WORLD;

Rough output:

grammar HelloWorld;

// parser rules
mySingleRule: HELLOWORLD;

// lexer rules
HELLOWORLD: 'Hello' 'World';