124 lines
4 KiB
Text
124 lines
4 KiB
Text
/-
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Copyright (c) 2020 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Authors: Leonardo de Moura
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-/
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import Lean.Message
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import Lean.InternalExceptionId
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import Lean.Data.Options
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namespace Lean
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/- Exception type used in most Lean monads -/
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inductive Exception
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| error (ref : Syntax) (msg : MessageData)
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| internal (id : InternalExceptionId)
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def Exception.toMessageData : Exception → MessageData
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| Exception.error _ msg => msg
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| Exception.internal id => id.toString
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def Exception.getRef : Exception → Syntax
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| Exception.error ref _ => ref
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| Exception.internal _ => Syntax.missing
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instance : Inhabited Exception := ⟨Exception.error (arbitrary _) (arbitrary _)⟩
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class Ref (m : Type → Type) :=
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(getRef : m Syntax)
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(withRef {α} : Syntax → m α → m α)
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export Ref (getRef)
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instance (m n : Type → Type) [Ref m] [MonadFunctor m n] [MonadLift m n] : Ref n := {
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getRef := liftM (getRef : m _),
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withRef := fun ref x => monadMap (m := m) (Ref.withRef ref) x
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}
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def replaceRef (ref : Syntax) (oldRef : Syntax) : Syntax :=
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match ref.getPos with
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| some _ => ref
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| _ => oldRef
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@[inline] def withRef {m : Type → Type} [Monad m] [Ref m] {α} (ref : Syntax) (x : m α) : m α := do
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let oldRef ← getRef
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let ref := replaceRef ref oldRef
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Ref.withRef ref x
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/- Similar to `AddMessageContext`, but for error messages.
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The default instance just uses `AddMessageContext`.
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In error messages, we may want to provide additional information (e.g., macro expansion stack),
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and refine the `(ref : Syntax)`. -/
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class AddErrorMessageContext (m : Type → Type) :=
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(add : Syntax → MessageData → m (Syntax × MessageData))
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instance (m : Type → Type) [AddMessageContext m] [Monad m] : AddErrorMessageContext m := {
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add := fun ref msg => do
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msg ← addMessageContext msg
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pure (ref, msg)
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}
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section Methods
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variables {m : Type → Type} [Monad m] [MonadExceptOf Exception m] [Ref m] [AddErrorMessageContext m]
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def throwError {α} (msg : MessageData) : m α := do
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let ref ← getRef
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let (ref, msg) ← AddErrorMessageContext.add ref msg
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throw $ Exception.error ref msg
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def throwUnknownConstant {α} (constName : Name) : m α :=
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throwError msg!"unknown constant '{mkConst constName}'"
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def throwErrorAt {α} (ref : Syntax) (msg : MessageData) : m α := do
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withRef ref $ throwError msg
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def ofExcept {ε α} [ToString ε] (x : Except ε α) : m α :=
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match x with
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| Except.ok a => pure a
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| Except.error e => throwError $ toString e
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def throwKernelException {α} [MonadOptions m] (ex : KernelException) : m α := do
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throwError $ ex.toMessageData (← getOptions)
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end Methods
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class MonadRecDepth (m : Type → Type) :=
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(withRecDepth {α} : Nat → m α → m α)
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(getRecDepth : m Nat)
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(getMaxRecDepth : m Nat)
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instance {ρ m} [Monad m] [MonadRecDepth m] : MonadRecDepth (ReaderT ρ m) := {
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withRecDepth := fun d x ctx => MonadRecDepth.withRecDepth d (x ctx),
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getRecDepth := fun _ => MonadRecDepth.getRecDepth,
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getMaxRecDepth := fun _ => MonadRecDepth.getMaxRecDepth
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}
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instance {ω σ m} [Monad m] [MonadRecDepth m] : MonadRecDepth (StateRefT' ω σ m) :=
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inferInstanceAs (MonadRecDepth (ReaderT _ _))
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@[inline] def withIncRecDepth {α m} [Monad m] [MonadRecDepth m] [MonadExceptOf Exception m] [Ref m] [AddErrorMessageContext m]
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(x : m α) : m α := do
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let curr ← MonadRecDepth.getRecDepth
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let max ← MonadRecDepth.getMaxRecDepth
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if curr == max then throwError maxRecDepthErrorMessage
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MonadRecDepth.withRecDepth (curr+1) x
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syntax "throwError! " ((interpolatedStr term) <|> term) : term
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syntax "throwErrorAt! " term:max ((interpolatedStr term) <|> term) : term
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macro_rules
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| `(throwError! $msg) =>
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if msg.getKind == interpolatedStrKind then
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`(throwError (msg! $msg))
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else
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`(throwError $msg)
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macro_rules
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| `(throwErrorAt! $ref $msg) =>
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if msg.getKind == interpolatedStrKind then
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`(throwErrorAt $ref (msg! $msg))
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else
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`(throwErrorAt $ref $msg)
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end Lean
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