What Am I Missing (HP-71B)

[Sylvain Cote]

(11-03-2014 10:45 AM)Les Bell Wrote:  Yes, the real problem is the "Illegal context" error messages on what looks like just about the simplest DEF FN examples. I must be overlooking something very obvious, but I can't think what. . .

I have entered your example and I do not get the illegal context message but I do get a parameter mismatch thought.

I did some reading and experimentations, this is my finding ...
- FN parameters are passed by values
- FN can access global variables
- FN local variables mask global variables
- FN parameters only accept string and simple numeric variables (no numeric array)

so the following works

10 OPTION BASE 0
20 DIM A(1), B(1)
30 A(0)=4 @ A(1)=4 @ B(0)=5 @ B(1)=4
40 DISP FND;FNE(0,1);FNF(A(0),B(0),A(1),B(1))
100 DEF FND=A(0)*B(0)+A(1)*B(1)
110 DEF FNE(I1,I2)=A(I1)*B(I1)+A(I2)*B(I2)
110 DEF FNF(V1,V2,V3,V4)=V1*V2+V3*V4

If I find a way to pass an array I will post it.

Best regards,

Sylvain