Re: [Bug-apl] APL fill elements

[Juergen Sauermann]

Hi Peter,

no there isn't. Fill items and Fill functions occur all over the place in APL2.
And they are function specific so that ↑ has other fill items (' ' and 0) than
+ (0) and × (1). On the other hand fill items are not at all related ⎕IO.

You can easily achieve what you are after like this:

      A←4 5
      B←3 2⍴42
      Z←A↑B
      Z
42 42 0 0 0
42 42 0 0 0
42 42 0 0 0
 0  0 0 0 0
      Z + ∼A↑(⍴B)⍴1
42 42 1 1 1
42 42 1 1 1
42 42 1 1 1
 1  1 1 1 1

/// Jürgen


On 08/09/2014 08:15 PM, Peter Teeson wrote:

Is there a nice way to set the fill element for arrays?
Right now it's 0 for numeric and ' ' for character.

Because my function, that is deliberately ⎕IO agnostic, produces an m by n array of different length vectors as a result of using X←(⊂matrix)foo¨matrix. These vectors are certain indices into the original matrix This is precisely what I want.

However in ⊃X each vector is filled with 0 - which, when ⎕IO is also 0, is also a legitimate index. And I don't want that. 

I suppose I could set ⎕IO locally but it doesn't appeal to my sense of elegance - although it would be practical! Sigh!

So it would be nice to allow me to set the fill element to something other than the default values.

Comments?

respect….

Peter