Deep amend

Deep amend

.[x;y[;f];z]

Deep Amend, also known as dmend or drill is a deep version of Amend which allows modification of elements which are nested deep inside an array.

Deep Amend takes 3 or 4 arguments, where:

• x is an array to amend
• y is the index route to amend
• z is the function to apply to those indices
• u (optional), is the second argument to z

It is very similar to Amend in its functionality. The main difference is that y when given an array indexes into subarrays when used.

 .[3 3#!9;1 1;-:]
0 1 2
3 -4 5
6 7 8

ngn/k

ngn/k's amend has z as the optional argument, instead of having f as an optional argument.