I want to parse a list of numbers and find the one that is
the closest to a target number:


proc closest {target args} {
set closest 9999999999999999999
puts $args
foreach i $args {
puts "i is $i"
if {$i > $target} {set diff [expr $i - $target]}
if {$target > $i} {set diff [expr $target - $i]}
if {$diff < $closest} {set closest $diff; set ret $i}
}
return $ret
}


Testing on Tkcon:

% closest 456 [list 45 256 987 599 362]
args is {45 256 987 599 362}
i is 45 256 987 599 362
missing operator at _@_
in expression "456 - 45 _@_256 987 599 362"

Well, so $args is a list. But $i is not treated as an item
of the list in the foreach loop. Why not?


Let's try again:

proc closest {target args} {
set closest 9999999999999999999
puts $args
foreach i {*}$args {
puts "i is $i"
if {$i > $target} {set diff [expr $i - $target]}
if {$target > $i} {set diff [expr $target - $i]}
if {$diff < $closest} {set closest $diff; set ret $i}
}
return $ret
}

% closest 456 [list 45 256 987 599 362]
args is {45 256 987 599 362}
i is 45
i is 256
i is 987
i is 599
i is 362
362

It works with the nipple! Why?

--
Luc

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 11/26/2022 9:59 PM, Michael Soyka wrote:

Hi Luc,

Lookup the documentation for "proc" and you'll see that "args" when used
as the last argument is special.

-mike

I meant to add that in your case, "args" is a list of lists:
{ {45 256 ...} }

On 11/26/2022 9:05 PM, Luc wrote:

I want to parse a list of numbers and find the one that is
the closest to a target number:


proc closest {target args}    {
    set closest 9999999999999999999
    puts $args
    foreach i $args    {
        puts "i is $i"
        if {$i     > $target}    {set diff [expr $i - $target]}
        if {$target > $i}        {set diff [expr $target - $i]}
        if {$diff < $closest}    {set closest $diff; set ret $i} >>     }
    return $ret
}


Testing on Tkcon:

% closest 456 [list 45 256 987 599 362]
args is {45 256 987 599 362}
i is 45 256 987 599 362
missing operator at _@_
in expression "456 - 45 _@_256 987 599 362"

Well, so $args is a list. But $i is not treated as an item
of the list in the foreach loop. Why not?


Let's try again:

proc closest {target args}    {
    set closest 9999999999999999999
    puts $args
    foreach i {*}$args    {
        puts "i is $i"
        if {$i     > $target}    {set diff [expr $i - $target]}
        if {$target > $i}        {set diff [expr $target - $i]}
        if {$diff < $closest}    {set closest $diff; set ret $i} >>     }
    return $ret
}

% closest 456 [list 45 256 987 599 362]
args is {45 256 987 599 362}
i is 45
i is 256
i is 987
i is 599
i is 362
362

It works with the nipple! Why?

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Hi Luc,

Lookup the documentation for "proc" and you'll see that "args" when used
as the last argument is special.

-mike

On 11/26/2022 9:05 PM, Luc wrote:

I want to parse a list of numbers and find the one that is
the closest to a target number:

proc closest {target args} {
set closest 9999999999999999999
puts $args
foreach i $args {
puts "i is $i"
if {$i > $target} {set diff [expr $i - $target]}
if {$target > $i} {set diff [expr $target - $i]}
if {$diff < $closest} {set closest $diff; set ret $i}
}
return $ret
}

Testing on Tkcon:

% closest 456 [list 45 256 987 599 362]
args is {45 256 987 599 362}
i is 45 256 987 599 362
missing operator at _@_
in expression "456 - 45 _@_256 987 599 362"

Well, so $args is a list. But $i is not treated as an item
of the list in the foreach loop. Why not?

Let's try again:

proc closest {target args} {
set closest 9999999999999999999
puts $args
foreach i {*}$args {
puts "i is $i"
if {$i > $target} {set diff [expr $i - $target]}
if {$target > $i} {set diff [expr $target - $i]}
if {$diff < $closest} {set closest $diff; set ret $i}
}
return $ret
}

% closest 456 [list 45 256 987 599 362]
args is {45 256 987 599 362}
i is 45
i is 256
i is 987
i is 599
i is 362
362

It works with the nipple! Why?

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

* Michael Soyka <[email protected]>
| Hi Luc,

| Lookup the documentation for "proc" and you'll see that "args" when
| used as the last argument is special.

After reading said documentation
https://www.tcl.tk/man/tcl/TclCmd/proc.html
you (Luc) will understand why

closest 456 45 256 987 599 362

closest 456 45 256 987 599 362 1 2 3 4 1000

work as well with your original version.

R'

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)