lib/utils/identifierMapping.js
function memoize(func) {
  const cache = new Map();

  return input => {
    let output = cache.get(input);

    if (output === undefined) {
      output = func(input);
      cache.set(input, output);
    }

    return output;
  };
}
function memoize(func) {
  const cache = new Map();

  return input => {
    let output = cache.get(input);

    if (output === undefined) {
      output = func(input);
      cache.set(input, output);
    }

    return output;
  };
}
function memoize ( func ) { const cache = new Map ( ) ; return input => { let output = cache . get ( input ) ; if ( output === undefined ) { output = func ( input ) ; cache . set ( input , output ) ; } return output ; } ; }
Super fast memoize for single argument functions.
Super fast memoize for single argument functions .