A DSL for generating the parser and CST typing

[diff3usion]

When I was working on the semantic analysis of CST with Typescript, I was bothered by the lack of typing hints, which inspires me to make a DSL for generating the typing and the parser codes at the same time. The syntax looks like this:

...
#
    constructor(tokens: TokenType[]) {
        super(tokens, {
            recoveryEnabled: true
        })
        const $ = this;
#
ArgumentSep {
    _Semicolon
    _Identifier
}
BacktrackPredicate {
    _LAngle
    |\_Identifier
     \*Statement
     \*StatementList
}
ArgumentGate {
    _RAngle
    |\_EscapedString
     \*BacktrackPredicate
}
...

More info can be found in the repo meta-chevrotain

I also noticed that there had already been some work on generating the types, but this project can still be a interesting alternative approach.

One possible future use case can be some highly interactive playground where such reduced syntax can be make user-friendly for people who would like to define their own DSL without much knowledge of javascript.

[bd82]

Hello @diff3usion and thanks for sharing 👍

Chevrotain used to include some APIs to assist in the creation of such DSLs

• https://github.com/Chevrotain/chevrotain/blob/5615b04937d78b8df22b4ab7d51df9a9e7942863/packages/website/docs/guide/custom_apis.md

However, these APIs have been deprecated to reduce the maintenance overhead of the library.
It is nice to see the lack of these APIs is not a blocker for the creation of such DSLs.

Another previous community effort in this area can be found here:

• https://www.npmjs.com/package/chevrotain-ebnf