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sequence :: (Traversable t, Monad m) => t (m a) -> m (t a)basic-prelude BasicPrelude Evaluate each monadic action in the structure from left to right, and collect the results. For a version that ignores the results see sequence_.
Examples
Basic usage: The first two examples are instances where the input and and output of sequence are isomorphic.>>> sequence $ Right [1,2,3,4] [Right 1,Right 2,Right 3,Right 4]
>>> sequence $ [Right 1,Right 2,Right 3,Right 4] Right [1,2,3,4]
The following examples demonstrate short circuit behavior for sequence.>>> sequence $ Left [1,2,3,4] Left [1,2,3,4]
>>> sequence $ [Left 0, Right 1,Right 2,Right 3,Right 4] Left 0
sequenceA :: (Traversable t, Applicative f) => t (f a) -> f (t a)basic-prelude BasicPrelude Evaluate each action in the structure from left to right, and collect the results. For a version that ignores the results see sequenceA_.
Examples
Basic usage: For the first two examples we show sequenceA fully evaluating a a structure and collecting the results.>>> sequenceA [Just 1, Just 2, Just 3] Just [1,2,3]
>>> sequenceA [Right 1, Right 2, Right 3] Right [1,2,3]
The next two example show Nothing and Just will short circuit the resulting structure if present in the input. For more context, check the Traversable instances for Either and Maybe.>>> sequenceA [Just 1, Just 2, Just 3, Nothing] Nothing
>>> sequenceA [Right 1, Right 2, Right 3, Left 4] Left 4
sequenceA_ :: (Foldable t, Applicative f) => t (f a) -> f ()basic-prelude BasicPrelude Evaluate each action in the structure from left to right, and ignore the results. For a version that doesn't ignore the results see sequenceA. sequenceA_ is just like sequence_, but generalised to Applicative actions.
Examples
Basic usage:>>> sequenceA_ [print "Hello", print "world", print "!"] "Hello" "world" "!"
sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()basic-prelude BasicPrelude Evaluate each monadic action in the structure from left to right, and ignore the results. For a version that doesn't ignore the results see sequence. sequence_ is just like sequenceA_, but specialised to monadic actions.
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basic-prelude BasicPrelude The subsequences function returns the list of all subsequences of the argument.
Laziness
subsequences does not look ahead unless it must:>>> take 1 (subsequences undefined) [[]] >>> take 2 (subsequences ('a' : undefined)) ["","a"]Examples
>>> subsequences "abc" ["","a","b","ab","c","ac","bc","abc"]
This function is productive on infinite inputs:>>> take 8 $ subsequences ['a'..] ["","a","b","ab","c","ac","bc","abc"]
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basic-prelude CorePrelude General-purpose finite sequences.
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basic-prelude CorePrelude The value of seq a b is bottom if a is bottom, and otherwise equal to b. In other words, it evaluates the first argument a to weak head normal form (WHNF). seq is usually introduced to improve performance by avoiding unneeded laziness. A note on evaluation order: the expression seq a b does not guarantee that a will be evaluated before b. The only guarantee given by seq is that the both a and b will be evaluated before seq returns a value. In particular, this means that b may be evaluated before a. If you need to guarantee a specific order of evaluation, you must use the function pseq from the "parallel" package.
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brick Brick.Types No documentation available.
visibilityRequests :: Result n -> ![VisibilityRequest]brick Brick.Types The list of visibility requests made by widgets rendered while rendering this one (used by viewports)
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brick Brick.Types No documentation available.