3651dc7618
The implementation is good enough for implementing extensible parsers, elaborators and tactics, but there are a few TODOs 1- We should have a better story for standalone applications. Most of them don't need `evalConst`, and the global table is just initialization overhead. 2- The global table introduces a dependency on the `Lean.Name` implementation. So, all standalone applications will depend on it. 3- We are not storing arity 0 constants in the table. This one should be easy to fix in the future.
40 lines
1.6 KiB
Text
40 lines
1.6 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 init.io
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import init.data.array
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import init.lean.name
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namespace Lean
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/- We mark this primitive as `unsafe` because it assumes the table is
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being accessed by a single thread. -/
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@[extern 2 "lean_modify_constant_table"]
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unsafe constant modifyConstTable (f : Array (Name × NonScalar) → Array (Name × NonScalar)) : IO Unit := default _
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/- We mark this primitive as `unsafe` because it assumes the table is
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being accessed by a single thread. -/
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@[extern 1 "lean_get_constant_table"]
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unsafe constant getConstTable : IO (Array (Name × NonScalar)) := default _
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/- We mark this primitive as `unsafe` because it assumes the table is
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being accessed by a single thread. We meet this requirement by invoking
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it after we have initialized all modules.
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See `src/init/init.cpp` -/
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@[export lean.sort_const_table_core]
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unsafe def sortConstTable : IO Unit :=
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modifyConstTable (λ cs, cs.qsort (λ e₁ e₂, Name.quickLt e₁.1 e₂.1))
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/- We make this primitive as `unsafe` because it uses `unsafeCast`, and
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the program may crash if the type provided by the user is incorrect.
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It also assumes there are no threads trying to update the table concurrently. -/
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unsafe def evalConst (α : Type) [Inhabited α] (c : Name) : IO α :=
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do cs ← getConstTable,
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match cs.binSearch (c, default _) (λ e₁ e₂, Name.quickLt e₁.1 e₂.1) with
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| some (_, v) := pure (unsafeCast v)
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| none := throw (IO.userError ("unknow constant '" ++ toString c ++ "'"))
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end Lean
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