29 lines
851 B
Text
29 lines
851 B
Text
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--| Remove first `n` elements of a list
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let Natural/greaterThanEqual =
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missing
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sha256:30ebfab0febd7aa0ccccfdf3dc36ee6d50f0117f35dd4a9b034750b7e885a1a4
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? ../Natural/greaterThanEqual.dhall
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let drop
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: ∀(n : Natural) → ∀(a : Type) → List a → List a
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= λ(n : Natural) →
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λ(a : Type) →
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λ(xs : List a) →
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List/fold
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{ index : Natural, value : a }
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(List/indexed a xs)
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(List a)
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( λ(x : { index : Natural, value : a }) →
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λ(xs : List a) →
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if Natural/greaterThanEqual x.index n
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then [ x.value ] # xs
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else xs
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)
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([] : List a)
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let example = assert : drop 2 Natural [ 2, 3, 5 ] ≡ [ 5 ]
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let example = assert : drop 5 Natural [ 2, 3, 5 ] ≡ ([] : List Natural)
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in drop
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