foreach problem

Hi all,
I know its simple but ...???

set l 1,0
set b 2,0

foreach pos {l b} {
resub -all {,} $pos {.} pos
}

The result should be:
set l -> 1.0
set b -> 2.0

The problem is "pos"?! But what's correct?

Thanks
Hans

Hans Herrmann wrote:
> Hi all,
> I know its simple but ...???
>
> set l 1,0
> set b 2,0
>
> foreach pos {l b} {

Here, pos takes on the values of "l" and "b".

>     resub -all {,} $pos {.} pos

So here, you're substituting periods for commas in "l" and "b", and
assigning the result to pos.

What you probably want is another level of look-up-the-variable, so the
regsub line should be

regsub -all {,} [set $pos] {.} [set pos]

The first time thru the loop, [set pos] returns "l" and [set $pos]
returns "1,0".  SO this translates to
regsub -all , 1,0 . l
which is what you want.

Basically, when you're looping over the names of variables, you have to
put an extra indirection in there.

HTH.

--
Darren New / San Diego, CA, USA (PST)
The samba was clearly inspired
by the margarita.

"Darren New" <dnew@san.rr.com> schrieb im Newsbeitrag
news:68Ioe.41400$ya2.26287@tornado.socal.rr.com...
> Hans Herrmann wrote: 
>
> Here, pos takes on the values of "l" and "b".
> 
>
> So here, you're substituting periods for commas in "l" and "b", and
> assigning the result to pos.
>
> What you probably want is another level of look-up-the-variable, so the
> regsub line should be
>
>   regsub -all {,} [set $pos] {.} [set pos]
>
> The first time thru the loop, [set pos] returns "l" and [set $pos] returns
> "1,0".  SO this translates to
>   regsub -all , 1,0 . l
> which is what you want.
>
> Basically, when you're looping over the names of variables, you have to
> put an extra indirection in there.
>
> HTH.
>
Hi Darren,
many thanks for your help!
Hans

Hans Herrmann wrote:
> Hi all,
> I know its simple but ...???
>
> set l 1,0
> set b 2,0
>

Are you trying to solve a localization issue here? Is it that you've
read in '1,0' ( == 1.0 == 1·0 ) and want it interpreted as a real? If so
I don't know how to do it but I would certainly like to know how to get
tcl to interpret these equivalent forms as reals.


Simon Geard

At 2005-06-05 03:12PM, Darren New <dnew@san.rr.com> wrote:
>  Hans Herrmann wrote: 
>
>  Here, pos takes on the values of "l" and "b".
> 
>
>  So here, you're substituting periods for commas in "l" and "b", and
>  assigning the result to pos.
>
>  What you probably want is another level of look-up-the-variable, so the
>  regsub line should be
>
>     regsub -all {,} [set $pos] {.} [set pos]
>
>  The first time thru the loop, [set pos] returns "l" and [set $pos]
>  returns "1,0".  SO this translates to
>     regsub -all , 1,0 . l
>  which is what you want.
>
>  Basically, when you're looping over the names of variables, you have to
>  put an extra indirection in there.

Alternatively, loop over the substituted values:
foreach pos [list $l $b] {
#...
}

--
Glenn Jackman
NCF Symin
glennj@ncf.ca

"Simon Geard" <simon@quintic.co.uk> schrieb im Newsbeitrag
news:42a40276$0$1717$ed2e19e4@ptn-nntp-reader04.plus.net...
> Hans Herrmann wrote: 
>
> Are you trying to solve a localization issue here? Is it that you've read
> in '1,0' ( == 1.0 == 1·0 ) and want it interpreted as a real? If so I
> don't know how to do it but I would certainly like to know how to get tcl
> to interpret these equivalent forms as reals.
>
>
> Simon Geard

Thanks to all!
You are very kind!
Hans

"Glenn Jackman" <xx087@freenet.carleton.ca> schrieb im Newsbeitrag
news:slrnda8nb8.5dj.xx087@smeagol.ncf.ca...
> At 2005-06-05 03:12PM, Darren New <dnew@san.rr.com> wrote:

> Alternatively, loop over the substituted values:
>    foreach pos [list $l $b] {
>        #...
>    }

Hi Glenn,
thanks for your answer but it doesn't work!

######
set a 1,0
set b 2,0

foreach pos [list $a $b]  {
regsub -all {,} $pos {.} pos
}
# ... result
set a -> 1,0
set b -> 2,0
# ???

Hans

At 2005-06-07 11:43AM, Hans Herrmann <lieber@doc-herrmann.de> wrote:
>  "Glenn Jackman" <xx087@freenet.carleton.ca> schrieb im Newsbeitrag
>  news:slrnda8nb8.5dj.xx087@smeagol.ncf.ca... 
> 
>
>  Hi Glenn,
>  thanks for your answer but it doesn't work!
>
>  ######
>  set a 1,0
>  set b 2,0
>
>  foreach pos [list $a $b]  {
>      regsub -all {,} $pos {.} pos
>  }
>  # ... result
>  set a -> 1,0
>  set b -> 2,0
>  # ???

Ah, sorry, I missed the point that you wanted to alter the variables
in-place.  In that case, Darren's advice is the way to go.

foreach pos_var {a b}  {
regsub -all {,} [set $pos_var] {.} $pos_var
puts "$pos_var -> [set $pos_var]"
}

Another approach to [regsub] is [string map]:
set a 1.000,05
set b 432.234,99
foreach pos_var {a b}  {
# tranlate comma to dot and dot to comma
set $pos_var [string map {, . . ,} [set $pos_var]];
puts "$pos_var -> [set $pos_var]"
}

--
Glenn Jackman
NCF Symin
glennj@ncf.ca

"Glenn Jackman" <xx087@freenet.carleton.ca> schrieb im Newsbeitrag
news:slrndabhqg.iom.xx087@smeagol.ncf.ca...
> At 2005-06-07 11:43AM, Hans Herrmann <lieber@doc-herrmann.de> wrote: 
>
> Ah, sorry, I missed the point that you wanted to alter the variables
> in-place.  In that case, Darren's advice is the way to go.
>
>    foreach pos_var {a b}  {
>        regsub -all {,} [set $pos_var] {.} $pos_var
>        puts "$pos_var -> [set $pos_var]"
>    }
>
> Another approach to [regsub] is [string map]:
>    set a 1.000,05
>    set b 432.234,99
>    foreach pos_var {a b}  {
>        # tranlate comma to dot and dot to comma
>        set $pos_var [string map {, . . ,} [set $pos_var]];
>        puts "$pos_var -> [set $pos_var]"
>    }
>
Hi Glenn,
thanks :-)
Hans

On 06/07/05 18:11, Glenn Jackman wrote:
> Ah, sorry, I missed the point that you wanted to alter the variables
> in-place.  In that case, Darren's advice is the way to go.
>
>     foreach pos_var {a b}  {
>         regsub -all {,} [set $pos_var] {.} $pos_var
>         puts "$pos_var -> [set $pos_var]"
>     }
>
> Another approach to [regsub] is [string map]:
>     set a 1.000,05
>     set b 432.234,99
>     foreach pos_var {a b}  {
>         # tranlate comma to dot and dot to comma
>         set $pos_var [string map {, . . ,} [set $pos_var]];
>         puts "$pos_var -> [set $pos_var]"
>     }
>
All these [set $pos_var] commands can get a bit confusing. Another
possibility I haven't seen mentioned sofar is to use upvar. I especially
find this method more convenient when you need to use the variable more
than once or twice inside the loop.

foreach varname {l b} {
upvar 0 $varname var
regsub -all {,} $var {.} var
puts "$varname -> $var"
}

Schelte
--
set Reply-To [string map {nospam schelte} $header(From)]