c54287fb0d
This PR modifies LCNF.toMonoType to use a more refined type erasure scheme, which distinguishes between irrelevant/erased information (represented by lcErased) and erased type dependencies (represented by lcAny). This corresponds to the irrelevant/object distinction in the old code generator.
33 lines
1 KiB
Text
33 lines
1 KiB
Text
import Lean
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/-- `erased α` is the same as `α`, except that the elements
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of `erased α` are erased in the VM in the same way as types
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and proofs. This can be used to track data without storing it
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literally. -/
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def Erased (α : Sort u) : Sort max 1 u :=
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Σ's : α → Prop, ∃ a, (fun b => a = b) = s
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namespace Erased
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/-- Erase a value. -/
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@[inline]
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def mk {α} (a : α) : Erased α :=
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⟨fun b => a = b, a, rfl⟩
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open Lean.Compiler
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set_option pp.explicit true
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set_option pp.funBinderTypes true
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set_option pp.letVarTypes true
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set_option trace.Compiler.result true
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/--
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info: [Compiler.result] size: 1
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def Erased.mk._redArg : PSigma lcErased lcErased :=
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let _x.1 : PSigma lcErased lcErased := PSigma.mk lcErased ◾ ◾ ◾;
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return _x.1
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[Compiler.result] size: 1
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def Erased.mk (α : lcErased) (a : lcAny) : PSigma lcErased lcErased :=
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let _x.1 : PSigma lcErased lcErased := PSigma.mk lcErased ◾ ◾ ◾;
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return _x.1
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-/
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#guard_msgs in
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run_meta Lean.Compiler.compile #[``Erased.mk]
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