From Newsgroup: comp.lang.tcl


I just realized, that

lsearch -real -index 0 {0 1.0} 1.00

does not find the 1.0 element in the given list!

Same for:

lsearch -real -index 0 {0 1.0} 1

Why is that???

Since "expr 1.0==1.00" and "expr 1.0==1" return true, I realy wonder...

Any explanation for this behavior?


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From Newsgroup: comp.lang.tcl

On 9/17/2025 10:19 AM, meshparts wrote:

I just realized, that

lsearch -real -index 0 {0 1.0} 1.00

does not find the 1.0 element in the given list!

Same for:

lsearch -real -index 0 {0 1.0} 1

Why is that???

Since "expr 1.0==1.00" and "expr 1.0==1" return true, I realy wonder...

Any explanation for this behavior?

Interesting. Tcl 8.6 gives the expected results, or so it seems at first:

% lsearch -real -index 0 {0 1.0} 1.0
1

Bu then look at these:

% lsearch -real -index 0 {0 1.0} 1.00
-1

% lsearch -real -index 0 {0 1.0} 1.000
-1


Convert your pattern to a real number doesn't seem to really help either:

% lsearch -real -index 0 {0 1.0} [expr 1.000]
1


% lsearch -real -index 0 {0 1.00} [expr 1.000]
-1







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From Newsgroup: comp.lang.tcl

On 17/09/2025 16:19, meshparts wrote:

lsearch -real -index 0 {0 1.0} 1.00

does not find the 1.0 element in the given list!

[snip]>

Any explanation for this behavior?

The matching style for lsearch defaults to -glob. The -real option is
only meaningful when used with the -exact option. And then it works as expected:

% lsearch -exact -real {0 1.0} 1.00
1
% lsearch -exact -real {0 1.0} 1
1

I concede that it would make sense for the -real option (and a few other options) to imply -exact.


Schelte

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From Newsgroup: comp.lang.tcl

Am 17.09.2025 um 17:26 schrieb Schelte:

On 17/09/2025 16:19, meshparts wrote:

lsearch -real -index 0 {0 1.0} 1.00

does not find the 1.0 element in the given list!

[snip]>

Any explanation for this behavior?

The matching style for lsearch defaults to -glob. The -real option is
only meaningful when used with the -exact option. And then it works as expected:

% lsearch -exact -real {0 1.0} 1.00
1
% lsearch -exact -real {0 1.0} 1
1

I concede that it would make sense for the -real option (and a few other options) to imply -exact.

Schelte

Oh, right! Thanks!
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From Newsgroup: comp.lang.tcl

On 9/17/2025 11:26 AM, Schelte wrote:

The matching style for lsearch defaults to -glob. The -real option is
only meaningful when used with the -exact option. And then it works as expected:

Nice!



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