55 lines
1.9 KiB
Text
55 lines
1.9 KiB
Text
/-
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Copyright (c) 2019 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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prelude
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import Lean.Meta.GlobalInstances
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namespace Lean.Meta
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private def canUnfoldDefault (cfg : Config) (info : ConstantInfo) : CoreM Bool := do
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match cfg.transparency with
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| .all => return true
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| .default => return !(← isIrreducible info.name)
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| m =>
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if (← isReducible info.name) then
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return true
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else if m == .instances && isGlobalInstance (← getEnv) info.name then
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return true
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else
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return false
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def canUnfold (info : ConstantInfo) : MetaM Bool := do
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let ctx ← read
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if let some f := ctx.canUnfold? then
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f ctx.config info
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else
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canUnfoldDefault ctx.config info
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/--
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Look up a constant name, returning the `ConstantInfo`
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if it should be unfolded at the current reducibility settings,
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or `none` otherwise.
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This is part of the implementation of `whnf`.
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External users wanting to look up names should be using `Lean.getConstInfo`.
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-/
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def getUnfoldableConst? (constName : Name) : MetaM (Option ConstantInfo) := do
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match (← getEnv).find? constName with
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| some (info@(.thmInfo _)) => getTheoremInfo info
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| some (info@(.defnInfo _)) => if (← canUnfold info) then return info else return none
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| some info => return some info
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| none => throwUnknownConstant constName
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/--
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As with `getUnfoldableConst?` but return `none` instead of failing if the constant is not found.
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-/
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def getUnfoldableConstNoEx? (constName : Name) : MetaM (Option ConstantInfo) := do
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match (← getEnv).find? constName with
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| some (info@(.thmInfo _)) => getTheoremInfo info
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| some (info@(.defnInfo _)) => if (← canUnfold info) then return info else return none
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| some info => return some info
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| none => return none
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end Meta
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