Linear string search perf

linear-search.js

(function() {

const Y_IX = 1e6;
const str = "x".repeat(Y_IX) + "y";


function regexp (str) {
  return /y/.exec(str).index;
}

function indexOf(str) {
  return str.indexOf("y");
}

function noop() { return Y_IX; }

// MEASUREMENT INFRASTRUCTURE

const applyFunctions = [
  regexp,
  indexOf,
  noop,
];

const ITERATIONS = 1e5;

function test(applyFun) {
  for (var i = 0; i < ITERATIONS; ++i) {
    if (applyFun(str) !== Y_IX) { throw 1 };
  }
}

// Warmup
for (const applyFun of applyFunctions) {
  console.time("First " + applyFun.name);
  applyFun(str);
  console.timeEnd("First " + applyFun.name);
  test(applyFun);
}

// Measure
for (const applyFun of applyFunctions) {
  console.time("Optimized " + applyFun.name);
  test(applyFun);
  console.timeEnd("Optimized " + applyFun.name);
}

}());