Tampermonkey, Convert SLR Parser to C matrix.

export.js

// ==UserScript==
// @name         Export SLR Parser Automata to C
// @namespace    http://tampermonkey.net/
// @version      2024-04-23
// @description  Export SLR Parser Automata to C
// @author       Ed
// @match        https://jsmachines.sourceforge.net/machines/slr.html
// @icon         https://www.google.com/s2/favicons?sz=64&domain=sourceforge.net
// @grant        none
// ==/UserScript==

/**
 * https://jsmachines.sourceforge.net/machines/slr.html
 * Export your parser automata to a plain C array
 */

(function() {
    'use strict';

    const button = document.createElement('button')
    button.innerText = 'EXPORT AUTOMATA TO C'
    button.addEventListener('click', exportAutomata)
    document.body.prepend(button)
})();

function exportAutomata() {
    console.debug('exporting automata...')
    const thead = window.lrTableView.childNodes[0].childNodes[0].getElementsByTagName('tr')[1]
    const [_, ACTION, GOTO] = thead.getElementsByTagName('th')
    const actions = parseInt(ACTION.getAttribute('colspan'))
    const gotos = parseInt(GOTO.getAttribute('colspan'))

    const tbody = window.lrTableView.childNodes[0].childNodes[1]
    const rows = Array.from(tbody.getElementsByTagName('tr'))

    const mat = rows.map(r => {
        const cols = Array.from(r.getElementsByTagName('td'))
        return cols.slice(1).map(c => {
            const text = c.innerText
            const match = /[sr](\d+)/.exec(text)
            if (match) {
                const value = parseInt(match[1])
                return text.startsWith('s') ? value
                                            : value + 512
            }

            const number = /\d+/.exec(text)
            if (number) {
                return parseInt(number)
            }

            if (text === 'acc') {
                return 512
            }

            return -1
        })
    })

    const cdef = `int const mat[${mat.length}][${actions + gotos}] = {\n  ` + mat.map(r => `{${r.join(', ')}}`).join(',\n  ') + '\n};';
    const blob = new Blob([cdef], {type:'text'})
    const url = URL.createObjectURL(blob)

    const anchor = document.createElement('a')
    anchor.setAttribute('href', url)
    anchor.setAttribute('download', 'mat.c')
    document.body.appendChild(anchor)
    anchor.click()
}