d954706fcf
Lean.Meta.Tactic.apply now accepts an ApplyConfig argument. `apply` now changes which metavariables are stored with choice of the newGoals config. This allows one to implement `fapply` and `eapply`. An example of this is given in tests/lean/run/apply_tac.lean. Closes #1045
33 lines
984 B
Text
33 lines
984 B
Text
import Lean
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open Lean
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open Lean.Elab
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open Lean.Meta
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open Lean.Elab.Tactic
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example (a b c : Nat) (h₁ : a = b) (h₂ : b = c) : a = c := by
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apply Eq.trans _ h₂ -- the metavars created during elaboration become new goals
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trace_state
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exact h₁
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example (a : Nat) : ∃ x, x = a := by
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apply Exists.intro -- the goal for the witness should occur "after" the goal for x = a
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trace_state
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rfl
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elab "fapply " e:term : tactic =>
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evalApplyLikeTactic (Meta.apply (cfg := {newGoals := ApplyNewGoals.all})) e
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elab "eapply " e:term : tactic =>
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evalApplyLikeTactic (Meta.apply (cfg := {newGoals := ApplyNewGoals.nonDependentOnly})) e
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example (a : Nat) : ∃ x, x = a := by
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eapply Exists.intro -- only metavars with out forward dependencies are added as goals.
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trace_state
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rfl
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example (a : Nat) : ∃ x, x = a := by
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fapply Exists.intro -- all unassigned metavars are added as new goals using the order they were created.
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trace_state
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exact a
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trace_state
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rfl
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