Re: [TCLCORE] Prototype Implementation of TIP 672 - $(expr) Syntax

[da S. P. J <pet...@fl...>]

{*} always comes at the start of a new argument.

[expr...] could come anywhere in a string passed to subst, so there is no guard against a random {=}{ sequence inside a string, which is currently completely valid TCL and much harder to find, especially in encoded strings. I don’t think it’s a viable option.

From: Colin Macleod via Tcl-Core <tcl...@li...>
Date: Monday, October 20, 2025 at 11:32
To: tcl...@li... <tcl...@li...>
Subject: Re: [TCLCORE] Prototype Implementation of TIP 672 - $(expr) Syntax
I would say {=}{expression} is more Tcl-ish, though two characters longer. It follows the precedent of {*}, and avoids the incompatibility of $(expression). I wonder if that could also be implemented by a simple macro-type substitution at the


I would say {=}{expression} is more Tcl-ish, though two characters longer.  It follows the precedent of {*}, and avoids the incompatibility of $(expression).  I wonder if that could also be implemented by a simple macro-type substitution at the parsing stage, as Eric has proposed.  If {=} was TIP-ed I would happily withdraw my competing TIP 676.

Colin.
On 20/10/2025 16:11, da Silva, Peter J wrote:
Obviously I think this is a great idea and I think anyone who actually uses $(thing) in production code is crazy, but when I brought it up it got shot down because it was apparently found in the wild in production code.

Pity it didn’t get into 9.0 :) but this would be a good era to do it in.