MaiaCC Parser Generator (tREx)

A JavaScript parser generator that reads XML produced from EBNF grammars and emits a working JavaScript lexer/parser.

Process Documentation

Mandatory cross-repository synchronization workflow:

• docs/Maia_Ecosystem_Synchronization_Protocol.md

MaiaCC tREx

tREx.sh is a wrapper script that can:

• Generate a parser from an XML grammar.
• Accept an EBNF grammar, convert it to XML first, then generate a parser.
• Convert EBNF to XML only (without generating a parser).

The script is located at bin/tREx.sh.

For parser-generator internals and self-host details, see parser-generator/README.md.

Requirements

• Node.js 18+ (tested on Node.js 24).

Usage

Run from the project root so relative paths resolve correctly.

bash bin/tREx.sh [options] <grammar-file> [output-parser-file]

Options

• --ebnf Treat <grammar-file> as EBNF and convert it to XML first.
• --xml Treat <grammar-file> as XML grammar (default).
• --to-xml <xml-file> Output XML path when using --ebnf.
• --only-xml Convert EBNF to XML only, do not generate parser.
• -h, --help Show help.

Common examples

1) Generate parser from XML

bash bin/tREx.sh parser-generator/examples/grammar.xml parser-generator/examples/arithmetic-parser.js

2) Generate parser from EBNF

bash bin/tREx.sh --ebnf parser-generator/examples/sample-grammar.ebnf parser-generator/examples/arithmetic-parser.js

3) Convert EBNF to XML only

bash bin/tREx.sh --ebnf --only-xml --to-xml parser-generator/examples/grammar.xml parser-generator/examples/sample-grammar.ebnf

Notes

• If --ebnf is used and --to-xml is omitted, the XML output is inferred from the input name.
• --only-xml requires --ebnf.
• --to-xml requires --ebnf.

Related docs

• parser-generator/README.md: generator internals, self-host flow, and test commands.
• Compatibility note: for parser-based programs that use the default collector, prefer collector.parse(parser, inputLabel) to get enriched parse errors with line/column/offset. See the section "Error Location Reporting With ParseTreeCollector" in parser-generator/README.md.