Meta Engineer?

This is available as Dict\pull_with_key in the www repository.

Returns a new dict with mapped keys and values

namespace HH\Lib\Dict;

function pull_with_key<Tk1, Tk2 as arraykey, Tv1, Tv2>(
  KeyedTraversable<Tk1, Tv1> $traversable,
  (function(Tk1, Tv1): Tv2) $value_func,
  (function(Tk1, Tv1): Tk2) $key_func,
): dict<Tk2, Tv2>;
  • values are the result of calling $value_func on the original value/key
  • keys are the result of calling $key_func on the original value/key. In the case of duplicate keys, later values will overwrite the previous ones.

Time complexity: O(n * (f1 + f2), where f1 is the complexity of $value_func and f2 is the complexity of $key_func Space complexity: O(n)


  • KeyedTraversable<Tk1,Tv1> $traversable
  • (function(Tk1, Tv1): Tv2) $value_func
  • (function(Tk1, Tv1): Tk2) $key_func


  • dict<Tk2, Tv2>