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import { IsEvenLength, Surround } from "./types.ts";import { assert } from "./except.ts";
/** * Surrounds the `str` with `surrounding`. `surrounding` must have an even length. * * @example * ``` * surround("foo", "()")      // "(foo)" * surround("foo", "({[]})")  // "({[foo]})" * ``` */export const surround = <A extends string, B extends string>(  str: A,  surrounding: B,): B extends "" ? A  : IsEvenLength<B> extends true ? Surround<A, B>  : never => {  if (typeof surrounding !== "string") return str as any;  assert(    surrounding.length % 2 === 0,    "surrounding string must have even length",  );  const half = surrounding.length / 2;  return `${surrounding.slice(0, half)}${str}${    surrounding.slice(half, half * 2)  }` as any;};
export default surround;