Re: [TCLCORE] TIP 672 Implementation Complete - Ready for Sponsorship

[Donal F. <don...@ma...>]

Just needs the option to do the $((...)) form (double parenthesis) to cover the likely bases for what we'll be picking between. I'm guessing that once we're closer to having a syntax picked, we'll need some really aggressive attempts to break the parser for all of this. Fun for test writers... ;-)

There will also need to be a bunch of cleaning up on the formal side (e.g., the TIP contains "TBD" for the Specification) before any vote. I don't expect a big problem there; just a "can't vote on this yet because we're still baking it".

Donal.

________________________________
From: EricT <tw...@gm...>
Sent: Wednesday, October 22, 2025 13:06
To: tcl...@li... <Tcl...@li...>
Cc: et...@ro... <et...@ro...>
Subject: [TCLCORE] TIP 672 Implementation Complete - Ready for Sponsorship

ZjQcmQRYFpfptBannerEnd
Hi everyone,

I wanted to update you on the status of TIP 672 (expression substitution syntax).

The prototype implementation is now complete and available at:
https://github.com/rocketship88/tcl-tip-672-prototype [github.com]<https://urldefense.com/v3/__https://github.com/rocketship88/tcl-tip-672-prototype__;!!PDiH4ENfjr2_Jw!FnU_lkuFMqro--EqlOuN1ArpdwtqBw99MRZ08bb9K5wa51ZyF6etbvazzvALIqobsO0M1KKypbJcYLKnPozRdEvqhQM$>

The implementation has been parameterized to support both discussed approaches with a simple compile-time flag:
- Mode 1: $(expr) syntax
- Mode 2: $=(expr) or $^(expr) - configurable character

Key features:
- Comprehensive test suite (82 tests covering edge cases)
- Minimal code changes (~100 lines)
- Clean integration with existing parser
- Full Tcl test suite passes (only 3 expected differences)

There is one known issue: a minor memory leak in the synthetic command strings that will need attention during integration.

At this point, I need a sponsor to upload the code to a TIP branch on Fossil so the core team can review and decide whether to adopt the TIP and, if so, which syntax to use. I'm available for any collaborative work, questions, or modifications needed.

I'm grateful for all the feedback and support from the community. I look forward to the next steps in the process.

Best regards,
Eric