1. Feedback on enhancement request
Hi,
I propose that a function can "return" multiple distinct values.
eg.
function fred(...)
integer return_code
sequence result
...
return {ret}, {result}
end function
integer a
sequence b
a , b = fred(...)
I find I often want to return two or more distinct values back from
function. I find it messy and difficult to re-read code after some
months that is like:
seq = fred()
if seq[1] = ... then
...do soemthing witg seq[2] ...
Would this also remove the need for pass by reference?
As an example
------
function swap(atom a, atom b)
return {b}, {a}
end function
variable1, variable2 = swap(variable1, variable2)
-------
Anyone have any thoughts?
Ray Smith
http://www.geocities.com/ray_223
2. Re: Feedback on enhancement request
- Posted by tone.skoda at siol.net
Feb 15, 2002
That is common problem also to me.
To do it like this:
fred_result = fred()
meaningful_name = fred_result [1]
if meaningful_name = ... then
is better than like this:
seq = fred()
if seq [1] = ... then
Selecting the right names for your variables in very important for readable
code. Maybe the most important part in writing readable code and also a
difficult one sometimes.
But I find your source code of your libraries very good and clear.
----- Original Message -----
From: "Ray Smith" <smithr at ix.net.au>
To: "EUforum" <EUforum at topica.com>
Sent: Saturday, February 16, 2002 4:29 AM
Subject: Feedback on enhancement request
>
> Hi,
>
> I propose that a function can "return" multiple distinct values.
>
> eg.
>
> function fred(...)
> integer return_code
> sequence result
>
> ...
>
> return {ret}, {result}
> end function
>
>
> integer a
> sequence b
>
> a , b = fred(...)
>
> I find I often want to return two or more distinct values back from
> function. I find it messy and difficult to re-read code after some
> months that is like:
>
> seq = fred()
> if seq[1] = ... then
> ...do soemthing witg seq[2] ...
>
> Would this also remove the need for pass by reference?
>
> As an example
>
> ------
> function swap(atom a, atom b)
> return {b}, {a}
> end function
>
> variable1, variable2 = swap(variable1, variable2)
> -------
>
> Anyone have any thoughts?
>
>
> Ray Smith
> http://www.geocities.com/ray_223
>
>
>
>
3. Re: Feedback on enhancement request
On Sat, 16 Feb 2002 03:29:22 +0000, you wrote:
>I find I often want to return two or more distinct values back from
>function.
It's the multiple assign which is hard. If you could write
{a,b}=swap(b,a) or massign({a,b},swap(b,a))
then return doesn't need to change. But multiple assign is horrible,
like the sudden English "or" separating the Euphoria code above.
Quickly, what's edge set to in:
{girth,widths,height,uplift,edge,jut,throw}={3,{7,6,5,2},89,2,{3,4,2},9,{3,4}}
OK, so you might know that fairly easily,or not, but you've just read
the line of code, so without looking, what was height just set to?
For something minimalist like swap you just really want a <=>
operator, there is no better way to make it nice&sweet&short. For
anything more complicated, though
temp=func(a,b) a=temp[1] b=temp[2]
is justified. I use it alot and it's not so bad if you do that rather
than have [1] & [2] litter the following code. Othertimes I enumerate,
eg
constant COUNT=1, AVERAGE=2 then
if result[COUNT]> threshold then
...
x=result[AVERAGE]*result[COUNT]
Pete
