af6d2077a0
This PR changes how match splitters are generated: Rather than rewriting the match statement, the match compilation pipeline is used again. The benefits are: * Re-doing the match compilation means we can do more intelligent book keeping, e.g. prove overlap assumptions only once and re-use the proof, or prune the context of the MVar to speed up `contradiction`. This may have allowed a different solution than #11200. * It would unblock #11105, as the existing splitter implementation would have trouble dealing with the matchers produced that way. * It provides the necessary machinery also for source-exposed “none of the above” bindings, a feature that we probably want at some point (and we mostly need to find good syntax for, see #3136, although maybe I should open a dedicated RFC). * It allows us to skip costly things during matcher creation that would only be useful for the splitter, and thus allows performance improvements like #11508. * We can drop the existing implementation. It’s not entirely free: * We have to run `simpH` twice, once for the match equations and once for the splitter.
26 lines
641 B
Text
26 lines
641 B
Text
-- set_option trace.Meta.Match.match true
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-- set_option trace.Meta.Match.matchEqs true
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def f (xs : List Nat) : Nat :=
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match xs with
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| [] => 1
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| [a, b] => (a + b).succ
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| _ => 2
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theorem ex1 (xs : List Nat) (hr : xs.reverse = xs) (ys : Nat) : ys > 0 → f xs > 0 := by
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simp [f]
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split
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next => intro hys; decide
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next => intro hys; apply Nat.zero_lt_succ
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next zs n₁ n₂ => intro hys; decide
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def g (xs : List Nat) : Nat :=
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match xs with
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| [a, b, c, d, e] => a + e + 1
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| _ => 1
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theorem ex2 (xs : List Nat) : g xs > 0 := by
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simp [g]
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split
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next a b c d e => apply Nat.zero_lt_succ
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next h => decide
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