Function put

docs/components/Playground.jsx:25–25

(c)

    let line = ''
    let col = 0
    const put = (c) => { line = line.slice(0, col) + c + line.slice(col + 1); col += 1 }
    for (const ch of text) {
        if (ch === '\n') { lines.push(line); line = ''; col = 0 }
        else if (ch === '\r') { col = 0 }