What does {*} do in TCL?

Question

I have used some TCL, but this construction stumps me.

When $res = \"Table does not exist\", what will the following return?

[list [list {*}$res]]
         


        

Answer 1

It's documented on the Tcl syntax manual page. It's dicussed on the Tcl wiki. It was introduced into the language in TIP 293 (its predecessor was TIP 157 where you can learn how it works).

Essentially, {*}$res will split the string into its whitespace-separated words. So, [list {*}$res] acts just like [split $res] (in this case).

The end result is a list with one element, the list of the words in $res.