Session dump from https://www.youtube.com/watch?v=M59FJbNFbUY&t=1335

multiple_representations.tcl

beni@beni580 ~> tclsh
% set n 42
42
% tcl::unsupported::representation $n
value is a pure string with a refcount of 4, object pointer at 0x5604d811de00, string representation "42"
% expr {$n + 1}
43
% tcl::unsupported::representation $n
value is a int with a refcount of 4, object pointer at 0x5604d811de00, internal representation 0x2a:(nil), string representation "42"
% 
% 
% 
% 
% set a {foo 12 bar {puts hello}}
foo 12 bar {puts hello}
% tcl::unsupported::representation $n
value is a int with a refcount of 4, object pointer at 0x5604d811de00, internal representation 0x2a:(nil), string representation "42"
% tcl::unsupported::representation $a
value is a pure string with a refcount of 4, object pointer at 0x5604d811e880, string representation "foo 12 bar {p..."
% list index $a 3
index {foo 12 bar {puts hello}} 3
% lindex $a 3
puts hello
% tcl::unsupported::representation $a
value is a list with a refcount of 4, object pointer at 0x5604d811e880, internal representation 0x5604d816ace0:(nil), string representation "foo 12 bar {p..."
% set inner [lindex $a 3]
puts hello
% puts inner
inner
% puts $inner
puts hello
% tcl::unsupported::representation $a
value is a list with a refcount of 4, object pointer at 0x5604d811e880, internal representation 0x5604d816ace0:(nil), string representation "foo 12 bar {p..."
% value is a list with a refcount of 4, object pointer at 0x5604d811e880, internal representation 0x5604d816ace0:(nil), string representation "foo 12 bar {p..."
invalid command name "value"
% tcl::unsupported::representation $inner
value is a pure string with a refcount of 3, object pointer at 0x5604d81b3d00, string representation "puts hello"
% lindex $inner 0
puts
% lindex $inner 1
hello
% tcl::unsupported::representation $inner
value is a list with a refcount of 3, object pointer at 0x5604d81b3d00, internal representation 0x5604d8137ba0:(nil), string representation "puts hello"
% eval [linder $a 3]
invalid command name "linder"
% eval [lindex $a 3]
hello
% tcl::unsupported::representation $inner
value is a bytecode with a refcount of 3, object pointer at 0x5604d81b3d00, internal representation 0x5604d816b4e0:(nil), string representation "puts hello"
% dict get $a bar
puts hello
% tcl::unsupported::representation $a
value is a dict with a refcount of 5, object pointer at 0x5604d811e880, internal representation 0x5604d816b5e0:(nil), string representation "foo 12 bar {p..."
% dict keys $a
foo bar
% lindex [lindex $a 3] 0
puts
% tcl::unsupported::representation $a
value is a list with a refcount of 3, object pointer at 0x5604d811e880, internal representation 0x5604d816a9e0:(nil), string representation "foo 12 bar {p..."
% tcl::unsupported::representation $inner
value is a bytecode with a refcount of 2, object pointer at 0x5604d81b3d00, internal representation 0x5604d816b4e0:(nil), string representation "puts hello"
% tcl::unsupported::representation [lindex $a 3]
value is a list with a refcount of 2, object pointer at 0x5604d811d530, internal representation 0x5604d8175780:(nil), string representation "puts hello"
% set d [dict create key value]
key value
% dict keys $d
key
% tcl::unsupported::representation $d
value is a dict with a refcount of 4, object pointer at 0x5604d8120d10, internal representation 0x5604d816b5e0:(nil), string representation "key value"
% set d [dict create key value]    
key value
% dict keys [set d2 [dict create key value]]
key
% tcl::unsupported::representation $d2
value is a dict with a refcount of 7, object pointer at 0x5604d8120d10, internal representation 0x5604d816b5e0:(nil), string representation "key value"
% tcl::unsupported::representation [dict create key value]
value is a dict with a refcount of 8, object pointer at 0x5604d8120d10, internal representation 0x5604d816b5e0:(nil), string representation "key value"
% tcl::unsupported::representation [list foo bar]
value is a list with a refcount of 2, object pointer at 0x5604d811dec0, internal representation 0x5604d8185680:(nil), no string representation
% set l [list foo bar]
foo bar
% tcl::unsupported::representation $l
value is a list with a refcount of 3, object pointer at 0x5604d81b6190, internal representation 0x5604d8185480:(nil), string representation "foo bar"
% list length $l
length {foo bar}
% llength $l
2
% llength [set l2 [list a b]]
2
% tcl::unsupported::representation $l2
value is a list with a refcount of 3, object pointer at 0x5604d81b67f0, internal representation 0x5604d8186480:(nil), no string representation
%