Function parseCore

src/compute-engine/latex-syntax/parse.ts:3211–3229

* Parse `latex` into a MathJSON expression, marking any leftover tokens with * an `Error` node. This is the core routine, without the trailing-punctuation * recovery or `preserveLatex` post-processing applied by `parse`.

(
  latex: string,
  dictionary: IndexedLatexDictionary,
  options: Readonly<ParseLatexOptions>
)

            if (typeof def.parse === 'function')
              result = def.parse(this, arg, { minPrec: 0 });
            else result = arg;
            if (result !== null) break;
          }
        }
      }
    }

    // Restore the index if we did not find a match
    if (result === null) this.index = index;

    return result;
  }

  parsePostfixOperator(
    lhs: MathJsonExpression | null,
    until?: Readonly<Terminator>
  ): MathJsonExpression | null {
    console.assert(lhs !== null); // @todo validate
    if (lhs === null || this.atEnd) return null;

    const start = this.index;
    // Skip visual space (e.g. `\ `, `\,`) before peeking postfix triggers, so