The goals are:

• to have a Langium grammar for Antlr4
• to convert existing Antlr4 grammars to Langium
• to have a zoo of grammars 🐘 🐍 🐻

• migrate lexer, including modes
• migrate parser, including ambiguity resolution
• implement scoping correctly, instead of hacking the document builder
• scanning all pom.xml within the antlr4-grammars repo (246/~300)
• covering 100% of all antlr4-grammars (215/246)... so that the Langium grammar for ANTLR4 accepts ANTLR4 inputs
• transpile 100% of grammars to recognize all examples in each grammar's examples folder
• add validators as needed

This repository uses Git submodules. So do your git clone with the flag --recurse-submodules to checkout the dependencies as well.

git clone https://github.com/langium/antlr4-grammar --recurse-submodules

During the migration of the ANTLR4 grammar for ANTLR4 itself, I will write down which steps were needed.

• migrate each ANTLR4 lexer rule of the pattern Rule: 'constant'; by ...

TokenBuilder:

• migrate each mode MMM by ...
• migrate each pushMode(MMM) by ...
• migrate each popMode() by ...