019f8fd211
git-subtree-dir: users/wpcarro git-subtree-mainline:464bbcb15cgit-subtree-split:24f5a642afChange-Id: I6105b3762b79126b3488359c95978cadb3efa789
59 lines
1 KiB
Elm
59 lines
1 KiB
Elm
module Misc exposing (..)
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import Array exposing (Array)
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comesAfter : a -> List a -> Maybe a
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comesAfter x xs =
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case xs of
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[] ->
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Nothing
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_ :: [] ->
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Nothing
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y :: z :: rest ->
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if y == x then
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Just z
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else
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comesAfter x (z :: rest)
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comesBefore : a -> List a -> Maybe a
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comesBefore x xs =
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case xs of
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[] ->
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Nothing
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_ :: [] ->
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Nothing
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y :: z :: rest ->
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if z == x then
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Just y
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else
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comesBefore x (z :: rest)
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find : (a -> Bool) -> List a -> Maybe a
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find pred xs =
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case xs |> List.filter pred of
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[] ->
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Nothing
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x :: _ ->
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Just x
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{-| Return the number of milliseconds that elapse during an interval in a
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`target` bpm.
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-}
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bpmToMilliseconds : Int -> Int
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bpmToMilliseconds target =
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let
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msPerMinute =
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1000 * 60
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in
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round (toFloat msPerMinute / toFloat target)
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