# Apply a List of Arguments to a List of Functions

Happy new year, everyone! I hope this is a good one.

The title doesn't really express well what I want to do, however, please see further explenation below.

Say, I have a list of functions flist - {f,g,h} where function f takes three arguments; function g takes six arguments; and function h takes four arguments. Furthermore, I have an argument list alist with randomly generated numbers which will serve as an input to the above functions.

How could I apply argument list alist to flist in such a way where each function in flist would take appropriate subset of elements from alist; whilst ensuring functions in flist do not share elements from alist.

Example

flist = {f,g,h};
alist = {1,2,3,4,5,6,7,8,9,10,11,12,13};

~magic~

f[1,2,3]
g[4,5,6,7,8,9]
h[10,11,12,13]


I know I could do something like

f @@ alist[[;;3]]
g @@ alist[[4;;9]]
h @@ alist[[10;;13]]


This said, I was wondering if there is a better way to do it. A more ~lazy~ approach.

## 1 Answer

 MapThread[Apply] @ {flist, TakeList[alist, {3, 6, 4}]}


f[1, 2, 3], g[4, 5, 6, 7, 8, 9], h[10, 11, 12, 13]}

Also

MapThread[# @@ #2 &] @ {flist, TakeList[alist, {3, 6, 4}]}


{f[1, 2, 3], g[4, 5, 6, 7, 8, 9], h[10, 11, 12, 13]}

Update: If TakeList is not available in your version, you can use InternalPartitionRagged or FoldPairList + TakeDrop:

InternalPartitionRagged[alist, {3, 6, 4}] ==
FoldPairList[TakeDrop, alist, {3, 6, 4}] ==
TakeList[alist, {3, 6, 4}]


True

• how would you implement above in Mathematica version 11.0.1.0? Unfortunately, I do not have TakeList function available :s – e.doroskevic Jan 14 at 16:20
• @e.doroskevic, please see the update. – kglr Jan 14 at 16:26