c7b8c5c6a6
Further alignment of `Array` and `List` lemmas. Moved lemmas about `List.toArray` to a separate file, and aligned lemmas about membership.
23 lines
782 B
Text
23 lines
782 B
Text
/-
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Copyright (c) 2024 Lean FRO. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Authors: Henrik Böving
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-/
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prelude
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import Init.Data.List.Basic
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/--
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Auxiliary definition for `List.toArray`.
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`List.toArrayAux as r = r ++ as.toArray`
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-/
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@[inline_if_reduce]
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def List.toArrayAux : List α → Array α → Array α
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| nil, r => r
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| cons a as, r => toArrayAux as (r.push a)
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/-- Convert a `List α` into an `Array α`. This is O(n) in the length of the list. -/
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-- This function is exported to C, where it is called by `Array.mk`
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-- (the constructor) to implement this functionality.
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@[inline, match_pattern, pp_nodot, export lean_list_to_array]
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def List.toArrayImpl (as : List α) : Array α :=
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as.toArrayAux (Array.mkEmpty as.length)
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