feat(Tactic/Translate): warn when adding a docstring to an existing declaration

[gasparattila]

---

• depends on: chore(Tactic/Translate): remove the deprecated @[to_additive "docstring"] syntax #41886

[github-actions]

PR summary 457f039fa3

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff (regex)

+ addStruct
+ addStruct'
+ mulStruct
+ mulStruct'
- mulTrivial'

You can run this locally as follows

## from your `mathlib4` directory:
git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci

## summary with just the declaration names:
../mathlib-ci/scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
../mathlib-ci/scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh in the mathlib-ci repository contains some details about this script.

Declarations diff (Lean)

✅ Lean-aware diff — post-build, computed from the Lean environment (commit 457f039).

• +0 new declarations
• −0 removed declarations

No declaration differences.

---

No changes to strong technical debt.

No changes to weak technical debt.

Current commit 457f039fa3
Reference commit ce279564d4

This script lives in the mathlib-ci repository. To run it locally, from your mathlib4 directory:

git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci
../mathlib-ci/scripts/reporting/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[JovanGerb]

Thanks for making the PR. I would be in favour of an even stronger restriction: if the translation already exists, then we should always give this warning, whether or not there is already a doc-string. Because it is better to give the docstring immediately, rather than later via to_additive.

[JovanGerb]

It would make more sense to just store the Option Syntax, because we can simply get the string from the syntax.

[gasparattila]

See #41886, which removes the deprecated "docstring" syntax and makes this field an Option (TSyntax _).

[mathlib-dependent-issues]

This PR/issue depends on:

• chore(Tactic/Translate): remove the deprecated @[to_additive "docstring"] syntax #41886
  By Dependent Issues (🤖). Happy coding!