06fb4bec52
This PR wraps the top-level command parser with `withPosition` to enforce indentation in `by` blocks, combined with an empty-by fallback for better error messages. This subsumes #3215 (which introduced `withPosition commandParser` but without the empty-by fallback). It is also related to #9524, which explores elaboration with empty tactic sequences — this PR reuses that idea for the empty-by fallback, so that a `by` not followed by an indented tactic produces an elaboration error (unsolved goals) rather than a parse error. **Changes:** - `topLevelCommandParserFn` now uses `(withPosition commandParser).fn`, setting the saved position at the start of each top-level command - `tacticSeqIndentGt` gains an empty tactic sequence fallback (`pushNone`) so that missing indentation produces an elaboration error (unsolved goals) instead of a parse error - `isEmptyBy` in `goalsAt?` removed: with strict `by` indentation, empty `by` blocks parse successfully via `pushNone` (producing empty nodes) rather than producing `.missing` syntax, making the `isEmptyBy` check dead code. The `isEmpty` helper in `isSyntheticTacticCompletion` continues to work correctly because it handles both `.missing` and empty nodes from `pushNone` (via the vacuously-true `args.all isEmpty` on `#[]`) - Test files updated to indent `by` blocks and expression continuations that were previously at column 0 **Behavior:** - Top-level `by` blocks now require indentation (column > 0 for commands at column 0) - Commands indented inside `section` require proofs to be indented past the command's column - `#guard_msgs in example : True := by` works because tactic indentation is checked against the outermost command's column - Expression continuations (not just `by`) must also be indented past the command, which is slightly more strict but more consistent - `have : True := by` followed by a dedent now correctly puts `this` in scope in the outer tactic block (the `have` is structurally complete with an unsolved-goal error, rather than a parse error) **Code changes observed in practice (lean4 test suite + Mathlib):** - `by` blocks: top-level `theorem ... := by` / `decreasing_by` followed by tactics at column 0 must be indented - `variable` continuations: `variable {A : Type*} [Foo A]\n{B : Type*}` where the second line starts at column 0 must be indented (most common category in Mathlib) - Expression continuations: `def f : T :=\nexpr` or `#synth Foo\n[args]` where the body/arguments start at column 0 - Structure literals: `.symm\n{ toFun := ...` where the struct literal starts at column 0 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
55 lines
1.2 KiB
Text
55 lines
1.2 KiB
Text
α : Type u_1
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as bs : List α
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⊢ as ++ bs ++ bs = as ++ (bs ++ bs)
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rewrite.lean:18:22-18:31: error: Tactic `rewrite` failed: Did not find an occurrence of the pattern
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(List.reverse ?as).reverse
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in the target expression
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as ++ [] ++ [] ++ bs ++ bs = as ++ (bs ++ bs)
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α : Type u_1
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as bs : List α
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⊢ as ++ [] ++ [] ++ bs ++ bs = as ++ (bs ++ bs)
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x y z : Nat
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h₁ : x = y
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h₂ : y = z
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⊢ x = z
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rewrite.lean:37:11-37:22: error: Tactic `rewrite` failed: Did not find an occurrence of the pattern in the current goal
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x y z : Nat
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h₁ : 0 + x = y
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h₂ : 0 + y = z
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⊢ x = z
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m n k : Nat
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h✝ : n = m
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h : k = m
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⊢ k = n
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rewrite.lean:55:69-56:10: error: unsolved goals
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α : Type
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p : Prop
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a b c : α
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h : p → a = b
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⊢ b = c
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α : Type
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p : Prop
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a b c : α
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h : p → a = b
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⊢ p
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f : Nat → Nat
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w : ∀ (n : Nat), f n = 0
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⊢ [f 1, 0, f 1, f 2] = [0, 0, 0, 0]
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f : Nat → Nat
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w : ∀ (n : Nat), f n = 0
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⊢ [0, f 2, 0, f 2] = [0, 0, 0, 0]
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f : Nat → Nat
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w : ∀ (n : Nat), f n = 0
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⊢ [0, f 2, 0, f 2] = [0, 0, 0, 0]
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f : Nat → Nat
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w : ∀ (n : Nat), f n = 0
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⊢ [f 1, 0, f 1, 0] = [0, 0, 0, 0]
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f : Nat → Nat
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w : ∀ (n : Nat), f n = 0
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⊢ [f 1, f 2, 0, f 2] = [0, 0, 0, 0]
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f : Nat → Nat
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w : ∀ (n : Nat), f n = 0
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⊢ [f 1, 0, f 1, f 2] = [0, 0, 0, 0]
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