Run results for: find n-th occurrence of a character

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.4 Safari/605.1.15

Browser: Safari 15

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
for	694162.5 Ops/sec
while	709727.1 Ops/sec
recur	699018.2 Ops/sec
continuation	678224.8 Ops/sec
throw-catch	278097.8 Ops/sec

HTML Preparation code:

<div id="for"></div>
<div id="while"></div>
<div id="rec"></div>
<div id="cc"></div>
<div id="catch"></div>
<div id="gen"></div>

Script Preparation code:

function nthIndexOfFor(text, search, n) {
    let i = 0;
    n--;
    for (i = text.indexOf(search); n > 0; i = text.indexOf(search, i + 1), n--) {
        if (i === -1) return -1;
    }
    return i;
}

function nthIndexOfWhile(text, search, n) {
    let i = text.indexOf(search);
    while (--n > 0) {
        if (i === -1) return -1;
        i = text.indexOf(search, i + 1);
    }
    return i;
}

function nthIndexOfRec(text, search, n) {
    const recur = (n, i) => {
        if (n <= 0) return i;
        const j = text.indexOf(search, i + 1);
        if (j === -1) return -1;
        return recur(n - 1, j);
    }
    return recur(n, -1);
}

function nthIndexOfCc(text, search, n) {
    let i = -1;
    const ret = (v) => i = v;
    const recur = (n, i) => {
        if (n <= 0) return void ret(i);
        const j = text.indexOf(search, i + 1);
        if (j === -1) return void ret(-1);
        recur(n - 1, j);
    }
    recur(n, -1);
    return i;
}

function nthIndexOfCatch(text, search, n) {
    const recur = (n, i) => {
        if (n <= 0) throw i;
        const j = text.indexOf(search, i + 1);
        if (j === -1) throw -1;
        recur(n - 1, j);
    }
    try {
        recur(n, -1);
    } catch (i) {
        return i;
    }
}

function nthIndexOfGen(text, search, n) {
    const recur = function*(n, i) {
        if (n <= 0) yield i;
        const j = text.indexOf(search, i + 1);
        if (j === -1) yield - 1;
        yield* recur(n - 1, j);
    };
    return recur(n, -1).next().value;
}

Tests:

for
let e = document.getElementById('for'); e.innerHTML = nthIndexOfFor('/1/23/7/3/19/61/2/4/27/18/', '/', 7) + ' ' + nthIndexOfFor('/1/23/7/3/19/61/2/4/27/18/', '/', 17);
while
let e = document.getElementById('while'); e.innerHTML = nthIndexOfWhile('/1/23/7/3/19/61/2/4/27/18/', '/', 7) + ' ' + nthIndexOfWhile('/1/23/7/3/19/61/2/4/27/18/', '/', 17);
recur
let e = document.getElementById('rec'); e.innerHTML = nthIndexOfRec('/1/23/7/3/19/61/2/4/27/18/', '/', 7) + ' ' + nthIndexOfRec('/1/23/7/3/19/61/2/4/27/18/', '/', 17);
continuation
let e = document.getElementById('cc'); e.innerHTML = nthIndexOfCc('/1/23/7/3/19/61/2/4/27/18/', '/', 7) + ' ' + nthIndexOfCc('/1/23/7/3/19/61/2/4/27/18/', '/', 17);
throw-catch
let e = document.getElementById('catch'); e.innerHTML = nthIndexOfCatch('/1/23/7/3/19/61/2/4/27/18/', '/', 7) + ' ' + nthIndexOfCatch('/1/23/7/3/19/61/2/4/27/18/', '/', 17);
generator
let e = document.getElementById('gen'); e.innerHTML = nthIndexOfGen('/1/23/7/3/19/61/2/4/27/18/', '/', 7) + ' ' + nthIndexOfGen('/1/23/7/3/19/61/2/4/27/18/', '/', 17);

Run results for: find n-th occurrence of a character

for

while

recur

continuation

throw-catch

generator