Anonymous Function And Optional Arguments

Question

Is there a way to get an optional arguments to work in an anonymous function.

Function[{Optional@a},If[a,True,False]]

Related http://mathematica.stackexchange.com/questions/29206/is-there-any-way-to-define-pure-functions-with-optional-arguments — Basheer Algohi, Nov 01 '16 at 02:28

score 2 · Accepted Answer · edited Apr 13 '17 at 12:55

2

Considering the other Q&A is much more likely to be found and the fact that my answer fits there quite nicely, I have moved my answer there.

edited Apr 13 '17 at 12:55

Community

1

answered Nov 01 '16 at 15:22

Jacob Akkerboom

12,215
45
79

William · Answer 2 · 2016-11-01T15:08:11.290

1

This appears to work.

optionalFu =
 Function[Null,
  ReplacePart[
   Function @@ Hold[
     Null,
     Quiet[## &, {Function::slotn}],
     HoldAll
     ]
   ,
   {2, 1, 0} -> Function @@ Hold[##]
   ], HoldAll]

and an example

optionalFu[If[ToString@#1 == "#1", True, False]][1]

edited Nov 01 '16 at 15:08

answered Nov 01 '16 at 15:03

William

7,595
2
22
70

Anonymous Function And Optional Arguments

2 Answers2