Skip to main content

Array.map_with_index

map_with_indexfunctionon_problems

Documentation​

Applies a function to each element of the array, returning the Vector of results.

The function is called with both the element index as well as the element itself.

Arguments​

  • function: A function that takes an index and an item and calculates a new value for at that index.
  • on_problems: Specifies how to handle any problems that arise in function.

Examples​

Sum numbers with their indices in an array.​

      [1, 2, 3].to_array.map_with_index (+)

Errors​

The result of Errors thrown when executing the function depend on on_problems:

  • Report_Error: The first error is thrown, and is wrapped in Map_Error.
  • No_Wrap: The first error is thrown, and is not wrapped in Map_Error.
  • Report_Warning: The result for that element is Nothing, the error is attached as a warning. Currently unimplemented.
  • Ignore: The result is Nothing, and the error is ignored.

Errors that are thrown when executing the supplied function are wrapped in Map_Error, which contains the index at which the error occurred.

In the Report_Warning case, only MAX_MAP_WARNINGS warnings are attached to result values. After that, the warnings are dropped, but a count of the additional warnings is attached in an Additional_Warnings warning.