Function createEditor

docs/components/editor.js:12–401

({ ed, defaultCode, onRun, highlight })

// `highlight(text) -> html` is injected (Shiki in the docs); CodeJar calls it on every render.
export function createEditor({ ed, defaultCode, onRun, highlight }) {

    // constants

    const PAIRS = { '(': ')', '[': ']', '{': '}', '"': '"', "'": "'" };
    const OPENERS = new Set(Object.keys(PAIRS));
    const CLOSERS = new Set(Object.values(PAIRS));
    const STRING_START = /^([fFrRbBuU]{0,2})("""|'''|"|')/;
    const WS = /[ \t]/;
    // `decreaseIndentPattern`, dedent on `:`.
    const DEDENT_RE = /^\s*(?:elif|else|except|finally|case)\b[^:]*:$/;

    // pure helpers

    // Walk from 0 to caret toggling code/string. `quote === ''` means code.
    const stringCtx = (src, caret) => {
        let i = 0, quote = '', isF = false;
        while (i < caret) {
            if (!quote) {
                if (src[i] === '#') {
                    const nl = src.indexOf('\n', i);
                    if (nl === -1 || nl >= caret) return { inStr: false, isF: false };
                    i = nl + 1; continue;
                }
                const m = src.slice(i).match(STRING_START);
                if (m && i + m[0].length <= caret) {
                    quote = m[2]; isF = /[fF]/.test(m[1]);
                    i += m[0].length; continue;
                }
                i++;
            } else {
                if (quote.length === 1 && src[i] === '\\') { i += 2; continue; }
                if (src.slice(i, i + quote.length) === quote) {
                    i += quote.length; quote = ''; isF = false; continue;
                }
                i++;
            }
        }
        return { inStr: !!quote, isF };
    };

    const lineAt = (text, caret) => {
        const start = text.lastIndexOf('\n', caret - 1) + 1;
        const nl = text.indexOf('\n', caret);
        const end = nl === -1 ? text.length : nl;
        return { start, end, body: text.slice(start, end), col: caret - start };
    };
    const firstNonWS = (s) => { for (let i = 0; i < s.length; i++) if (!WS.test(s[i])) return i; return s.length; };
    
    // `prevIndentTabStop`, distance to the previous tab stop from `col`.
    const prevTabDist = (col) => { const r = col % TAB_SIZE; return r === 0 ? TAB_SIZE : r; };

    // Full lines covered by `sel`; excludes the trailing line if `sel.end` sits exactly past a `\n`.
    const lineRange = (text, sel) => {
        const start = text.lastIndexOf('\n', sel.start - 1) + 1;
        const anchor = (sel.end > sel.start && text[sel.end - 1] === '\n') ? sel.end - 1 : sel.end;
        let end = text.indexOf('\n', anchor);
        if (end === -1) end = text.length;