create readme for std/bytes (#4876)

std/bytes/README.md

@@ -0,0 +1,79 @@
+# bytes
+
+bytes module is made to provide helpers to manipulation of bytes slice.
+
+# usage
+
+All the following functions are exposed in `mod.ts`
+
+## findIndex
+
+Find first index of binary pattern from given binary array.
+
+```typescript
+import { findIndex } from "https://deno.land/std/bytes/mod.ts";
+
+findIndex(
+  new Uint8Array([1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 3]),
+  new Uint8Array([0, 1, 2])
+);
+
+// => returns 2
+```
+
+## findLastIndex
+
+Find last index of binary pattern from given binary array.
+
+```typescript
+import { findLastIndex } from "https://deno.land/std/bytes/mod.ts";
+
+findLastIndex(
+  new Uint8Array([0, 1, 2, 0, 1, 2, 0, 1, 3]),
+  new Uint8Array([0, 1, 2])
+);
+
+// => returns 3
+```
+
+## equal
+
+Check whether given binary arrays are equal to each other.
+
+```typescript
+import { equal } from "https://deno.land/std/bytes/mod.ts";
+
+equal(new Uint8Array([0, 1, 2, 3]), new Uint8Array([0, 1, 2, 3])); // returns true
+equal(new Uint8Array([0, 1, 2, 3]), new Uint8Array([0, 1, 2, 4])); // returns false
+```
+
+## hasPrefix
+
+Check whether binary array has binary prefix.
+
+```typescript
+import { hasPrefix } from "https://deno.land/std/bytes/mod.ts";
+
+hasPrefix(new Uint8Array([0, 1, 2]), new Uint8Array([0, 1])); // returns true
+hasPrefix(new Uint8Array([0, 1, 2]), new Uint8Array([1, 2])); // returns false
+```
+
+## repeat
+
+Repeat bytes of given binary array and return new one.
+
+```typescript
+import { repeat } from "https://deno.land/std/bytes/mod.ts";
+
+repeat(new Uint8Array([1]), 3); // returns Uint8Array(3) [ 1, 1, 1 ]
+```
+
+## concat
+
+Concatenate two binary arrays and return new one.
+
+```typescript
+import { concat } from "https://deno.land/std/bytes/mod.ts";
+
+concat(new Uint8Array([1, 2]), new Uint8Array([3, 4])); // returns Uint8Array(4) [ 1, 2, 3, 4 ]
+```