Re: The best way to copy a list?

Not sure I understand the question. Why not just
set b $a
?
Also, your code will not always give identical results using
expr ([expr {$x}] is not always $x). For example,
% set a {a 0x10 b}
a 0x10 b
% set b [lmap x $a {expr {$x}}]
a 16 b
You could use one of the following forms instead
% set b [lmap x $a {lindex $x}]
a 0x10 b
% set b [lmap x $a {string cat $x}]
a 0x10 b
% set b [lmap x $a {return -level 0 $x}]
a 0x10 b
but as I said, why not just set a $b ?
/Ashok
set a {a 0x10 b}
On 6/18/2025 12:49 PM, Mark Summerfield wrote:

Is using `lmap` the best way to copy a list? For example:
      package require struct::list 1
     set a {a bc def ghij klmno}
     # is the following the best way to copy a list?
     set b [lmap x $a {expr {$x}}]
     puts "a={$a} b={$b} a==b=[struct::list equal $a $b]"
 Output:
      a={a bc def ghij klmno} b={a bc def ghij klmno} a==b=1