Benchmark value slice, update function

benchmarks/value-slice.bench.ts

@@ -0,0 +1,211 @@
+import { describe, bench, it, expect } from "vitest";
+
+const CASES = [
+  {
+    text: "test=example",
+    start: 5,
+    end: 12,
+    expected: "example",
+  },
+  {
+    text: "test=",
+    start: 5,
+    end: 5,
+    expected: "",
+  },
+  {
+    text: "test= example ",
+    start: 5,
+    end: 14,
+    expected: "example",
+  },
+  {
+    text: "test=example ",
+    start: 5,
+    end: 13,
+    expected: "example",
+  },
+  {
+    text: "test= example",
+    start: 5,
+    end: 13,
+    expected: "example",
+  },
+  {
+    text: "test= \t ",
+    start: 5,
+    end: 8,
+    expected: "",
+  },
+];
+
+function valueSliceDoThenWhile(str: string, min: number, max: number) {
+  let start = min;
+  let end = max;
+
+  do {
+    const code = str.charCodeAt(start);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+  } while (++start < end);
+
+  while (end > start) {
+    const code = str.charCodeAt(end - 1);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+    end--;
+  }
+
+  return str.slice(start, end);
+}
+
+function valueSliceDoThenWhileEmptyString(
+  str: string,
+  min: number,
+  max: number,
+) {
+  let start = min;
+  let end = max;
+
+  do {
+    const code = str.charCodeAt(start);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+  } while (++start < end);
+
+  while (end > start) {
+    const code = str.charCodeAt(end - 1);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+    end--;
+  }
+
+  return start === end ? "" : str.slice(start, end);
+}
+
+function valueSliceDoThenWhileExitEarly(str: string, min: number, max: number) {
+  if (min === max) return "";
+  let start = min;
+  let end = max;
+
+  do {
+    const code = str.charCodeAt(start);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+  } while (++start < end);
+
+  while (end > start) {
+    const code = str.charCodeAt(end - 1);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+    end--;
+  }
+
+  return str.slice(start, end);
+}
+
+function valueSliceTwoWhile(str: string, min: number, max: number) {
+  let start = min;
+  let end = max;
+
+  while (start < end) {
+    const code = str.charCodeAt(start);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+    start++;
+  }
+
+  while (end > start) {
+    const code = str.charCodeAt(end - 1);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+    end--;
+  }
+
+  return str.slice(start, end);
+}
+
+function valueSliceTwoWhileExitEarly(str: string, min: number, max: number) {
+  if (min === max) return "";
+  let start = min;
+  let end = max;
+
+  while (start < end) {
+    const code = str.charCodeAt(start);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+    start++;
+  }
+
+  while (end > start) {
+    const code = str.charCodeAt(end - 1);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+    end--;
+  }
+
+  return str.slice(start, end);
+}
+
+function valueSliceTwoDoWhile(str: string, min: number, max: number) {
+  let start = min;
+  let end = max;
+
+  do {
+    const code = str.charCodeAt(start);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+  } while (++start < end);
+
+  do {
+    const code = str.charCodeAt(end - 1);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+  } while (--end > start);
+
+  return str.slice(start, end);
+}
+
+function valueSliceTwoDoWhileExitEarly(str: string, min: number, max: number) {
+  if (min === max) return "";
+  let start = min;
+  let end = max;
+
+  do {
+    const code = str.charCodeAt(start);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+  } while (++start < end);
+
+  do {
+    const code = str.charCodeAt(end - 1);
+    if (code !== 32 /*   */ && code !== 9 /* \t */) break;
+  } while (--end > start);
+
+  return str.slice(start, end);
+}
+
+function valueSliceThenTrim(str: string, min: number, max: number) {
+  return str.slice(min, max).trim();
+}
+
+describe.each(CASES)("valueSlice $text", ({ text, start, end, expected }) => {
+  bench("two while", () => {
+    valueSliceTwoWhile(text, start, end);
+  });
+
+  bench("two while (exit early)", () => {
+    valueSliceTwoWhileExitEarly(text, start, end);
+  });
+
+  bench("two do...while", () => {
+    valueSliceTwoDoWhile(text, start, end);
+  });
+
+  bench("two do...while (exit early)", () => {
+    valueSliceTwoDoWhileExitEarly(text, start, end);
+  });
+
+  bench("do...while then while", () => {
+    valueSliceDoThenWhile(text, start, end);
+  });
+
+  bench("do...while then while (exit early)", () => {
+    valueSliceDoThenWhileExitEarly(text, start, end);
+  });
+
+  bench("do...while then while (empty string check)", () => {
+    valueSliceDoThenWhileEmptyString(text, start, end);
+  });
+
+  bench("slice then trim", () => {
+    valueSliceThenTrim(text, start, end);
+  });
+});