Re: Multiple return values

Arthur.Chance@Smallworld.co.uk (Arthur Chance) writes:


>Most programming languages allow procedures with multiple arguments
>(in some cases allowing them to be used in curried form as well), but
>very few languages allow multiple return values [,,,]
>Why is this?


A lot of the problem is due to syntax.
Everyobe likes to write things like


a = b*sin(c)


where sin is a function invocation.
If we define a routine like sincos(x), how are we going to use it
in an expression?


One attractive approach is used by Beta (a European project).
They seem to have rethought a lot of ideas from ground zero.
First off, assignment works left to right, like this


a + b => c


(I'm approximating the actual symbols, since I can't remember them).


Or


a + b => c => d


Or


a + b, c + d => e, f


Or


sincos(x) => y, z


Or


x => sincos => y, z


Or


1, 2 => sumdifrev => AplusB, AminusB, BminusA


where sumdifrev might be defined like


sumdifrev(int x, int y)
return x+y, x-y, y-x


Or


x => sincos => sumdifrev => x, y, z


There used to be a fair amount about the language on the net, along
with some implementations. Haven't looked in a while.


Preston Briggs
--

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