HH\Map::takeWhile

Returns a Map containing the keys and values of the current Map up to but not including the first value that produces false when passed to the specified callback.

Description

public function takeWhile(
  (function(Tv):bool) $fn,
): Map<Tk,Tv>

Returns a Map containing the keys and values of the current Map up to but not including the first value that produces false when passed to the specified callback.

The returned Map will always be a proper subset of the current Map.

Parameters

  • (function(Tv):bool) $fn - The callback that is used to determine the stopping condition.

Return Values

  • Map<Tk,Tv> - A Map that is a proper subset of the current Map up until the callback returns false.