diff --git a/src/library/tactic/exact_tactic.cpp b/src/library/tactic/exact_tactic.cpp index be9e5a234..f54804e7f 100644 --- a/src/library/tactic/exact_tactic.cpp +++ b/src/library/tactic/exact_tactic.cpp @@ -33,9 +33,18 @@ tactic exact_tactic(elaborate_fn const & elab, expr const & e, bool enforce_type return none_proof_state(); } expr t = head(gs).get_type(); - bool report_unassigned = false; - if (auto new_e = elaborate_with_respect_to(env, ios, elab, new_s, e, some_expr(t), - report_unassigned, enforce_type_during_elaboration)) { + bool report_unassigned = enforce_type_during_elaboration; + optional new_e; + try { + new_e = elaborate_with_respect_to(env, ios, elab, new_s, e, some_expr(t), + report_unassigned, enforce_type_during_elaboration); + } catch (exception &) { + if (s.report_failure()) + throw; + else + return none_proof_state(); + } + if (new_e) { goals const & gs = new_s.get_goals(); if (gs) { goal const & g = head(gs); diff --git a/tests/lean/exact_partial.lean.expected.out b/tests/lean/exact_partial.lean.expected.out index 5c0d29084..ce63e3b2c 100644 --- a/tests/lean/exact_partial.lean.expected.out +++ b/tests/lean/exact_partial.lean.expected.out @@ -1,3 +1,13 @@ +exact_partial.lean:4:19: error: don't know how to synthesize placeholder +a b : Prop, +a_1 : a, +a_2 : b +⊢ a +exact_partial.lean:4:21: error: don't know how to synthesize placeholder +a b : Prop, +a_1 : a, +a_2 : b +⊢ b exact_partial.lean:4:2: error:invalid 'exact' tactic, term still contains metavariables after elaboration and.intro ?M_1 ?M_2 proof state: diff --git a/tests/lean/exact_partial2.lean b/tests/lean/exact_partial2.lean new file mode 100644 index 000000000..022ee2006 --- /dev/null +++ b/tests/lean/exact_partial2.lean @@ -0,0 +1,4 @@ +example (a b c : nat) (h₁ : a = b) (h₂ : b = c) : a = c := +begin + exact (eq.trans h₁ _) +end diff --git a/tests/lean/exact_partial2.lean.expected.out b/tests/lean/exact_partial2.lean.expected.out new file mode 100644 index 000000000..d470edfd8 --- /dev/null +++ b/tests/lean/exact_partial2.lean.expected.out @@ -0,0 +1,21 @@ +exact_partial2.lean:3:21: error: don't know how to synthesize placeholder +a b c : nat, +h₁ : a = b, +h₂ : b = c +⊢ b = c +exact_partial2.lean:3:2: error:invalid 'exact' tactic, term still contains metavariables after elaboration + eq.trans h₁ ?M_1 +proof state: +a b c : nat, +h₁ : a = b, +h₂ : b = c +⊢ a = c +exact_partial2.lean:4:0: error: don't know how to synthesize placeholder +a b c : nat, +h₁ : a = b, +h₂ : b = c +⊢ a = c +exact_partial2.lean:4:0: error: failed to add declaration '14.0' to environment, value has metavariables +remark: set 'formatter.hide_full_terms' to false to see the complete term + λ (a b c : nat) (h₁ : …) (h₂ : …), + ?M_1 diff --git a/tests/lean/run/543.lean b/tests/lean/run/543.lean new file mode 100644 index 000000000..a47caa5e1 --- /dev/null +++ b/tests/lean/run/543.lean @@ -0,0 +1,4 @@ +example (a b c : nat) (h₁ : a = b) (h₂ : b = c) : b = c := +begin + (exact h₁ | exact h₂) +end