b763ab8a5e
This PR addresses two review points on `IO.CancelToken`: * `set` now resolves the underlying promise *before* writing the `Bool` fast-path flag, so observing `isSet = true` implies any synchronously chained `onSet` callback has already run. The previous order (flag first, then resolve) was a subtle footgun: code seeing `isSet = true` could not rely on the cancellation task having fired. * The underlying promise and the task it produces are kept private. The prior `task : Task (Option Unit)` accessor is removed; consumers should use `onSet` to react to cancellation. A comment on the structure records that re-exposing the task in the future requires re-auditing the order in `set` for races between the promise and the `Bool` flag. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com> Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
240 lines
4.9 KiB
Text
240 lines
4.9 KiB
Text
import Lean
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/-!
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# Tests for delaboration of constants (and name unresolution)
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-/
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set_option linter.unusedVariables false
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/-!
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Make sure unresolution avoids conflicts.
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-/
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def A.B.x : Nat := 0
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def A.B'.x : Nat := 0
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/-- info: x : Nat -/
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#guard_msgs in open A B in #check (A.B.x)
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/-- info: B'.x : Nat -/
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#guard_msgs in open A B in #check (A.B'.x)
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/-- info: B.x : Nat -/
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#guard_msgs in open A B B' in #check (A.B.x)
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/-- info: B'.x : Nat -/
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#guard_msgs in open A B B' in #check (A.B'.x)
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/-!
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Another conflict check.
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-/
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def B.x : Nat := 0
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/-- info: A.B.x : Nat -/
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#guard_msgs in open A in #check (A.B.x)
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-- Resolution accepts this exact match.
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/-- info: B.x : Nat -/
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#guard_msgs in open A in #check (B.x)
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/-!
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Opening does not shadow the `x` that's already in `B`.
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-/
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namespace B
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open A.B
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/-- info: A.B.x : Nat -/
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#guard_msgs in #check (_root_.A.B.x)
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/-- info: x : Nat -/
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#guard_msgs in #check (_root_.B.x)
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/-- info: x : Nat -/
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#guard_msgs in #check (x)
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end B
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/--
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A global `x` needs the `_root_` qualifier.
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-/
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def x : Nat := 0
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namespace B
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/-- info: _root_.x : Nat -/
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#guard_msgs in #check (_root_.x)
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/-- info: x : Nat -/
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#guard_msgs in #check (B.x)
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end B
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/-!
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Name that shadows a local constant needs `_root_`.
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-/
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/--
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trace: id : Nat
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⊢ _root_.id 2 = 2
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-/
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#guard_msgs in
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example (id : Nat) : _root_.id 2 = 2 := by
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trace_state
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rfl
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/-!
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Even with `id.{1}` notation, the name `id` must not shadow the local constant.
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-/
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/--
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trace: id : Nat
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⊢ Eq.{1} (_root_.id.{1} 2) 2
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-/
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#guard_msgs in
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set_option pp.universes true in
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example (id : Nat) : _root_.id 2 = 2 := by
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trace_state
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rfl
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/-!
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In `pp.fullNames` mode, local name shadowing is still checked.
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-/
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/--
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trace: id : Nat
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⊢ _root_.id 2 = 2
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-/
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#guard_msgs in
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set_option pp.fullNames true in
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example (id : Nat) : _root_.id 2 = 2 := by
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trace_state
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rfl
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/-- info: `_root_.id -/
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#guard_msgs in
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variable (id : Nat) in
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#eval Lean.Elab.Command.runTermElabM fun _ =>
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Lean.unresolveNameGlobalAvoidingLocals ``id (fullNames := true)
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/-!
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`match` shadowing test. This used to print the first `match` arm as
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`| Bool.true => 0`, which is incorrect, since `Bool.true` resolves to `MatchTest1.Bool.true`
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-/
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namespace MatchTest1
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def Bool.true := 0
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set_option linter.constructorNameAsVariable false in
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def f (true : Bool) : Nat :=
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match true with
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| _root_.Bool.true => 0
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| false => 1
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/--
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info: def MatchTest1.f : Bool → Nat :=
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fun true =>
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match true with
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| _root_.Bool.true => 0
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| false => 1
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-/
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#guard_msgs in
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#print f
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/-- info: Bool.true : Nat -/
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#guard_msgs in #check (Bool.true)
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end MatchTest1
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/-!
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`match` shadowing test. This used to print the first `match` arm as
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`| Bool.true => 0`, which is incorrect, since `Bool.true` resolves to the local variable.
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-/
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namespace MatchTest2
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set_option linter.constructorNameAsVariable false in
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def f (true : Bool) : Nat :=
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let Bool.true := 1
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match true with
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| _root_.Bool.true => 0
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| false => 1
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/--
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info: def MatchTest2.f : Bool → Nat :=
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fun true =>
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have Bool.true := 1;
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match true with
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| _root_.Bool.true => 0
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| false => 1
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-/
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#guard_msgs in
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#print f
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end MatchTest2
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/-!
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`match` shadowing test. Similar to `MatchTest2`, but `| Bool.false =>` is correct.
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-/
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namespace MatchTest3
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set_option linter.constructorNameAsVariable false in
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def f (true : Bool) :=
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let Bool.true := true
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let false := true
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match true with
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| _root_.Bool.true => false
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| Bool.false =>
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match true with
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| Bool.false => false
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| false => Bool.true
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/--
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info: def MatchTest3.f : Bool → Bool :=
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fun true =>
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have Bool.true := true;
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have false := true;
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match true with
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| _root_.Bool.true => false
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| Bool.false =>
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match true with
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| Bool.false => false
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| false => Bool.true
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-/
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#guard_msgs in open Bool in #print f
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end MatchTest3
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namespace PrvTest.NS1
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private abbrev fst : Nat × Nat → Nat := fun s => s.1
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private abbrev snd : Nat × Nat → Nat := fun s => s.2
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/-!
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The private names get unresolved. Previously this would print as
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`PrvTest.NS1.fst (x, x) = PrvTest.NS1.snd (x, x)`.
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-/
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/--
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trace: x : Nat
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⊢ fst (x, x) = snd (x, x)
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-/
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#guard_msgs in
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example (x : Nat) : fst (x,x) = snd (x,x) := by
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trace_state
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rfl
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end NS1
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export NS1 (fst)
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/-!
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Private names get unresolved with respect to the namespace, and aliases are respected too.
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-/
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/--
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trace: x : Nat
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⊢ fst (x, x) = NS1.snd (x, x)
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-/
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#guard_msgs in
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example (x : Nat) : fst (x,x) = NS1.snd (x,x) := by
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trace_state
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rfl
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end PrvTest
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/-!
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The name `IO.CancelToken.promise✝` is a private imported name.
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-/
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/--
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info: def IO.CancelToken.set : IO.CancelToken → BaseIO Unit :=
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fun tk => do
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IO.Promise.resolve () (IO.CancelToken.promise✝ tk)
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ST.Ref.set (IO.CancelToken.setRef✝ tk) true
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-/
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#guard_msgs in #print IO.CancelToken.set
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/-!
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Even if `IO` is opened, it won't print as `CancelToken.promise✝`, but the full name.
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-/
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/--
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info: def IO.CancelToken.set : CancelToken → BaseIO Unit :=
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fun tk => do
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Promise.resolve () (IO.CancelToken.promise✝ tk)
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ST.Ref.set (IO.CancelToken.setRef✝ tk) true
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-/
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#guard_msgs in open IO in #print IO.CancelToken.set
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