Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Christian Gollwitzer <auriocus@gmx.de>
Newsgroups: comp.lang.tcl
Subject: Re: a typeof command for debugging?
Date: Sat, 21 Jun 2025 15:58:50 +0200
Organization: A noiseless patient Spider
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> shows you the last type that was used on that object (besides string):
> 
> (chris) 50 % set a [expr {23*5}]
> 115
> (chris) 51 % tcl::unsupported::representation $a
> value is a int with a refcount of 4, object pointer at 0x55d6b8f8b320, 
> internal representation 0x73:(nil), string representation "115"
> 
> 
>           Christian

PS: Since you are new to Tcl, please have a look at the following:

(chris) 52 % set a {1 2 3 4}
1 2 3 4
(chris) 53 % tcl::unsupported::representation $a
value is a pure string with a refcount of 5, object pointer at 
0x55d6b8f8ac90, string representation "1 2 3 4"
(chris) 54 % lindex $a 2
3
(chris) 55 % tcl::unsupported::representation $a
value is a list with a refcount of 4, object pointer at 0x55d6b8f8ac90, 
internal representation 0x55d6b8c06cf0:(nil), string representation "1 2 
3 4"
(chris) 56 %

Also, the {} do not make the list, they are a quoting mechanism. You 
will get an identical result if you use "":
(chris) 61 % tcl::unsupported::representation $b
value is a pure string with a refcount of 5, object pointer at 
0x55d6b8f85860, string representation "1 2 3 4 5 6"
(chris) 62 % lindex $b 2
3
(chris) 63 % tcl::unsupported::representation $b
value is a list with a refcount of 4, object pointer at 0x55d6b8f85860, 
internal representation 0x55d6b8f14b40:(nil), string representation "1 2 
3 4 5 6"
(chris) 64 %


And, there is "constant sharing". After you ran the previous examples, 
try with another surprise:

(chris) 64 % set c "1 2 3 4"
1 2 3 4
(chris) 65 % tcl::unsupported::representation $c
value is a list with a refcount of 9, object pointer at 0x55d6b8f8ac90, 
internal representation 0x55d6b8c06cf0:(nil), string representation "1 2 
3 4"
(chris) 66 %


	Christian