Can programs have optional arguments?

[webmasterpdx]

Is it possible to write programs with optional arguments with default values? If so, what is the syntax?
Thx
-Donald

[Carlos295pz]

It is not possible, it is very related to define polymorphic functions and that is not possible in HP PPL, the alternatives can be to create 2 independent functions, or send a parameter that determines the different type of action you want to have on the data sent.

[Joe Horn]

Another option, although awkward, is possible: Make the input a string, and then parse the string yourself in your program.

[webmasterpdx]

Thank you

[Tyann]

Bonjour

J'ai déja fait ce genre de choses en utilisant une liste pour
transmettre/recevoir les paramètres.



Hello

I've already done this sort of thing using a list for
transmit / receive parameters.

[webmasterpdx]

I'm thinking like a function that has:
func(a,b,[c]), like some of the library functions....
You can create 2 functions but you can't do it like this:
EXPORT func(a,b,c=0)
...

I don't see how a list lets you do this...?
Thx
-D

[Tyann]

Bonjour, Hello

Par exemple :
For exemple :

Code:


Export Func(p)
BEGIN
Local a,b,c
a:=p(1);b:=p(2);
IFERR c:=p(3) THEN c:=0; END;
....
....
END;

Func({10,15,2}) -> c=2
Func({10,15}) -> c=0

C'est un peu artisanal mais cela fonctionne.
It's a little crafty but it works.

Si il y a plusieurs arguments optionnels et d'autres obligatoires vous pouvez mixer.
If there are several optional arguments and mandatory others you can mix.

Code:


EXPORT Func(a,b,p)
BEGIN
LOCAL c,d,e
IF TYPE(p)==6 THEN
 c:=p(1);d:=p(2);e:=p(3)
ELSE
 c:=p;d:='def value';e:='def value';
END;
...
...
END;

Espérant vous avoir aidé.
Hoping you helped.

[cyrille de brébisson]

Hello,

PPL does not support this for user functions. sorry.
You can "emulate" it (as suggesteed before) either by creating 2 distinct functions (func2 and func3, for respectivly 2 and 3 args for example) and/or by the use of a list of input parameters.

Cyrille

[parisse]

Giac has support for default parameters, for example

Code:

f(x=3):=x*x; f(); f(5)

but it is probably too recent to be in the CAS of the current HP firmware.

[webmasterpdx]

Good!