invoke callback for vim9script, vim9cmd, def

[mattn]

Add Vim9 Script Support via Callback Mechanism

Summary

This PR adds a callback mechanism to seamlessly support Vim9 Script parsing in vim-vimlparser. The parser now detects vim9script, vim9cmd, and def commands and invokes corresponding callbacks, allowing integration with dedicated Vim9 parsers such as vim-vim9parser.

Changes

• Added callback support to VimLParser constructor (accepts callbacks as second parameter)
• Implemented invoke_callback() method to trigger registered callbacks
• Added detection for vim9script and vim9cmd commands
• Callbacks are invoked when parsing:
  • vim9script → vim9script_callback
  • vim9cmd → vim9cmd_callback
  • def → def_callback
• Each callback receives the AST node and the command content

Use Case

This enables tools like language servers and linters to:

1. Parse legacy VimL code using vim-vimlparser
2. Delegate Vim9 syntax parsing to vim-vim9parser via callbacks
3. Support both VimL and Vim9 Script in a single codebase without switching parsers

Example

const { VimLParser, StringReader } = require('vimlparser.js');
const { Vim9Parser } = require('vim9parser.js');

const callbacks = {
  vim9script_callback: (node, content) => {
    console.log('Vim9 script detected at line', node.pos.lnum);
  },
  def_callback: (node, content) => {
    const vim9parser = new Vim9Parser();
    const vim9ast = vim9parser.parse(content);
    // Process Vim9 function definition
  }
};

const parser = new VimLParser(false, callbacks);
const ast = parser.parse(reader);

Related

• vim-vim9parser - Dedicated Vim9 Script parser

Note

Please note that vim-vim9parser is still under development and does not yet fully support all Vim9 Script features. This callback mechanism provides the foundation for Vim9 support, with parser completeness improving over time.