Re: how do you --> two variables?
On 2020-01-22 10:25, ToddAndMargo via perl6-users wrote:
On 2020-01-21 16:17, Todd Chester via perl6-users wrote:
Hi All,
What is the syntax for returning two variable from a sub?
> sub x(--> Int, UInt) { return(-2,4) };
===SORRY!=== Error while compiling:
Malformed return value (return constraints only allowed at the end of
the signature)
--> sub x(--> Int⏏, UInt) { return(-2,4) };
Many thanks,
-T
The guys on the chat line gave me a work around:
subset Tuple where * ~~ (Int, UInt, Str);
sub f($a,$b,$c --> Tuple) { ($a,$b,$c) };
say f(-1, 'x', 5)
# out of order, fails.
And I just added:
RFE: returns for multiple variables #152
https://github.com/Raku/problem-solving/issues/152
And thanks to the guys on the chat line, I hvae a pretty
workaround.
Re: how do you --> two variables?
On 2020-01-21 16:17, Todd Chester via perl6-users wrote:
Hi All,
What is the syntax for returning two variable from a sub?
> sub x(--> Int, UInt) { return(-2,4) };
===SORRY!=== Error while compiling:
Malformed return value (return constraints only allowed at the end of
the signature)
--> sub x(--> Int⏏, UInt) { return(-2,4) };
Many thanks,
-T
The guys on the chat line gave me a work around:
subset Tuple where * ~~ (Int, UInt, Str);
sub f($a,$b,$c --> Tuple) { ($a,$b,$c) };
say f(-1, 'x', 5)
# out of order, fails.
Re: how do you --> two variables?
> On 22 Jan 2020, at 01:17, Todd Chester via perl6-users
> wrote:
>
> Hi All,
>
> What is the syntax for returning two variable from a sub?
>
> > sub x(--> Int, UInt) { return(-2,4) };
>
> ===SORRY!=== Error while compiling:
> Malformed return value (return constraints only allowed at the end of the
> signature)
> --> sub x(--> Int⏏, UInt) { return(-2,4) };
Raku *ALWAYS* only returns a *SINGLE* value.
That value may be a List.
The comma is the operator that creates Lists.
`return 1,2,3` is therefore returning a List with 1, 2 and 3 as its elements.
if you say: `my ($a,$b,$c)`, you're creating a List with three variables in
them.
if you say: `my ($a,$b,$c) = foo` and `sub foo() { return 1,2,3 }` you will
effectively assign a list of values to a list of variables, assigning 1 to $a,
2 to $b, 3 to $c.
how do you --> two variables?
Hi All,
What is the syntax for returning two variable from a sub?
> sub x(--> Int, UInt) { return(-2,4) };
===SORRY!=== Error while compiling:
Malformed return value (return constraints only allowed at the end of
the signature)
--> sub x(--> Int⏏, UInt) { return(-2,4) };
Many thanks,
-T
