Grammar no-compile example

index.js

  import { i, re } from '@bablr/boot';
  import { buildNumber } from '@bablr/agast-vm-helpers';

  import * as Space from '@bablr/language-en-blank-space';

  export const dependencies = { Space };

  export function* eatMatchTrivia() {
    if (yield i`match(/[ \t\r\n]/)`) {
      return yield i`eat(<#*Space:Space>)`;
    }
    return null;
  }

  export const grammar = class Markdown {
    constructor() {
      this.covers = new Map();
      this.covers.set(
        Symbol.for('@bablr/node'),
        new Set(['Punctuator', 'Root', 'Paragraph', 'Heading', 'HeadingLevel', 'Literal']),
      );
      this.attributes = this.attributes || new Map();
      this.attributes.set('HeadingLevel', ['depth']);
    }

    *[Symbol.for('@bablr/fragment')]() {
      yield* eatMatchTrivia();
      yield i`eat(<> 'Root')`;
      yield* eatMatchTrivia();
    }

    *Root() {
      yield i`eat(<Any> 'children[]' [
        <Heading /#/>
        <Paragraph /[a-zA-Z]/>
        <#*Space:Space /[ \r\n\t]/>
      ])`;
    }

    *Heading() {
      yield i`eat(<*HeadingLevel> 'level')`;
      yield i`eat(<*Literal /.+/> 'text')`;
    }

    *HeadingLevel() {
      const match = yield i`eatMatch(/#+ /)`;
      if (!match) return;

      const depth = buildNumber(match[0].value.length - 1);
      yield i`bindAttribute('depth' ${depth})`;
    }

    *Paragraph() {
      while (yield i`eatMatch(<*Literal /.+/> 'children[]')`);
    }

    *Punctuator({ intrinsicValue }) {
      if (!intrinsicValue) throw new Error('Intrinsic productions must have value');

      yield i`eat(${intrinsicValue})`;
    }

    *Any({ value: matchers, ctx }) {
      for (const matcher of ctx.unbox(matchers)) {
        if (yield i`eatMatch(${matcher})`) break;
      }
    }
  };

  export const canonicalURL = 'https://bablr.org/languages/markdown';