feat: require indented tactic sequence after top-level by#13217
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feat: require indented tactic sequence after top-level by#13217
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This PR adds `checkColGtDefault`, a variant of `checkColGt` that defaults to checking against column 0 when no position has been saved via `withPosition`. Previously, `checkColGt` was a no-op at the top level, allowing `by` blocks to have un-indented tactic sequences: ```lean theorem foo (h : True) : True := by exact h -- was accepted, now requires indentation ``` `tacticSeqIndentGt` now uses `checkColGtDefault` instead of `checkColGt`, so `by`, `decreasing_by`, and `·` consistently require indented tactics at all levels. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Adapt to leanprover/lean4#13217 which requires indented tactic sequences after `by` and `decreasing_by`. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Adapt to leanprover/lean4#13217. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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…approach) This uses `withPosition commandParser` at the top level to enforce indentation in `by` blocks, combined with an empty-by fallback for better error messages. Compare with checkColPosGt approach in #13217. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Adapt to leanprover/lean4#13217 which requires indented tactic sequences after `by` and `decreasing_by`. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Adapt to leanprover/lean4#13217. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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…approach) This uses `withPosition commandParser` at the top level to enforce indentation in `by` blocks, combined with an empty-by fallback for better error messages. Compare with checkColPosGt approach in #13217. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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This is not good, but #13229 is promising. |
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This PR makes two changes to
tacticSeqIndentGt(used byby,decreasing_by,·, andfinally):Strict indentation at the top level. Adds
checkColPosGt, a variant ofcheckColGtthatdefaults to checking against column 0 when no position has been saved via
withPosition.Previously,
checkColGtwas a no-op at the top level, allowingbyblocks to haveun-indented tactic sequences:
Empty tactic sequence fallback. When no appropriately indented content follows,
tacticSeqIndentGtfalls back to an empty tactic sequence (likeby {}) instead of a parseerror. This produces an elaboration error (unsolved goals) rather than a syntax error, which
gives better IDE support (goal display, completions) in incomplete tactic blocks.
This can be subsumed later by a more principled approach of wrapping
topLevelCommandParserFnwith
withPosition(cf. #3215).Related: #3215, #9524. Implements parts of #3555.
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