lakutata/src/lib/base/internal/IEEE754.mjs

An IoC-based universal application framework.

function t(t, e, o, l, i) {
    let n;
    let s;
    const a = i * 8 - l - 1;
    const h = (1 << a) - 1;
    const f = h >> 1;
    let w = -7;
    let M = o ? i - 1 : 0;
    const c = o ? -1 : 1;
    let p = t[e + M];
    M += c;
    n = p & (1 << -w) - 1;
    p >>= -w;
    w += a;
    while (w > 0) {
        n = n * 256 + t[e + M];
        M += c;
        w -= 8;
    }
    s = n & (1 << -w) - 1;
    n >>= -w;
    w += l;
    while (w > 0) {
        s = s * 256 + t[e + M];
        M += c;
        w -= 8;
    }
    if (n === 0) {
        n = 1 - f;
    } else if (n === h) {
        return s ? NaN : (p ? -1 : 1) * Infinity;
    } else {
        s = s + Math.pow(2, l);
        n = n - f;
    }
    return (p ? -1 : 1) * s * Math.pow(2, n - l);
}

function e(t, e, o, l, i, n) {
    let s;
    let a;
    let h;
    let f = n * 8 - i - 1;
    const w = (1 << f) - 1;
    const M = w >> 1;
    const c = i === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0;
    let p = l ? 0 : n - 1;
    const N = l ? 1 : -1;
    const r = e < 0 || e === 0 && 1 / e < 0 ? 1 : 0;
    e = Math.abs(e);
    if (isNaN(e) || e === Infinity) {
        a = isNaN(e) ? 1 : 0;
        s = w;
    } else {
        s = Math.floor(Math.log(e) / Math.LN2);
        if (e * (h = Math.pow(2, -s)) < 1) {
            s--;
            h *= 2;
        }
        if (s + M >= 1) {
            e += c / h;
        } else {
            e += c * Math.pow(2, 1 - M);
        }
        if (e * h >= 2) {
            s++;
            h /= 2;
        }
        if (s + M >= w) {
            a = 0;
            s = w;
        } else if (s + M >= 1) {
            a = (e * h - 1) * Math.pow(2, i);
            s = s + M;
        } else {
            a = e * Math.pow(2, M - 1) * Math.pow(2, i);
            s = 0;
        }
    }
    while (i >= 8) {
        t[o + p] = a & 255;
        p += N;
        a /= 256;
        i -= 8;
    }
    s = s << i | a;
    f += i;
    while (f > 0) {
        t[o + p] = s & 255;
        p += N;
        s /= 256;
        f -= 8;
    }
    t[o + p - N] |= r * 128;
}

export { t as readIEEE754, e as writeIEEE754 };