inter

Some general transformation where the arguments that are not present are calculated from the one data argument a being just present. Can be used to contstruct function a -> d from some additional ideas.

inter c0 c1 is a list of all possible points of intersection between curves c0 and c1 : if (u,v,w,x) is returned by inter, then curve c0 may intersect with c1 between parameter values u and v, which corresponds to parameter values between w and x for c1. The implementation guarantees that all actual solutions are found, but possibly false solutions may also be returned.

Intersection of regular expressions

interact f takes the entire input from stdin and applies f to it. The resulting string is written to the stdout device. Note that this operation is lazy, which allows to produce output even before all input has been consumed. This operation may fail with the same errors as getContents and putStr.

Examples

>>> interact (\str -> str ++ str)
> hi :)
hi :)
> ^D
hi :)

>>> interact (const ":D")
:D

>>> interact (show . words)
> hello world!
> I hope you have a great day
> ^D
["hello","world!","I","hope","you","have","a","great","day"]

intercalate xs xss is equivalent to (concat (intersperse xs xss)). It inserts the list xs in between the lists in xss and concatenates the result.

Laziness

intercalate has the following properties:

>>> take 5 (intercalate undefined ("Lorem" : undefined))
"Lorem"

>>> take 6 (intercalate ", " ("Lorem" : undefined))
"Lorem*** Exception: Prelude.undefined

Examples

>>> intercalate ", " ["Lorem", "ipsum", "dolor"]
"Lorem, ipsum, dolor"

>>> intercalate [0, 1] [[2, 3], [4, 5, 6], []]
[2,3,0,1,4,5,6,0,1]

>>> intercalate [1, 2, 3] [[], []]
[1,2,3]

The intersect function takes the list intersection of two lists. It is a special case of intersectBy, which allows the programmer to supply their own equality test.

Examples

>>> [1,2,3,4] `intersect` [2,4,6,8]
[2,4]

If equal elements are present in both lists, an element from the first list will be used, and all duplicates from the second list quashed:

>>> import Data.Semigroup

>>> intersect [Arg () "dog"] [Arg () "cow", Arg () "cat"]
[Arg () "dog"]

However if the first list contains duplicates, so will the result.

>>> "coot" `intersect` "heron"
"oo"

>>> "heron" `intersect` "coot"
"o"

If the second list is infinite, intersect either hangs or returns its first argument in full. Otherwise if the first list is infinite, intersect might be productive:

>>> intersect [100..] [0..]
[100,101,102,103...

>>> intersect [0] [1..]
* Hangs forever *

>>> intersect [1..] [0]
* Hangs forever *

>>> intersect (cycle [1..3]) [2]
[2,2,2,2...

The intersectBy function is the non-overloaded version of intersect. It is productive for infinite arguments only if the first one is a subset of the second.

The intersperse function takes an element and a list and `intersperses' that element between the elements of the list.

Laziness

intersperse has the following properties

>>> take 1 (intersperse undefined ('a' : undefined))
"a"

>>> take 2 (intersperse ',' ('a' : undefined))
"a*** Exception: Prelude.undefined

Examples

>>> intersperse ',' "abcde"
"a,b,c,d,e"

>>> intersperse 1 [3, 4, 5]
[3,1,4,1,5]

Allow asynchronous exceptions to be raised even inside mask, making the operation interruptible (see the discussion of "Interruptible operations" in Exception). When called outside mask, or inside uninterruptibleMask, this function has no effect.

Insert an m between each pair of t m.

>>> intercalate1 ", " $ "hello" :| ["how", "are", "you"]
"hello, how, are, you"

>>> intercalate1 ", " $ "hello" :| []
"hello"

>>> intercalate1 mempty $ "I" :| ["Am", "Fine", "You?"]
"IAmFineYou?"

'intersperse x xs' alternates elements of the list with copies of x.

intersperse 0 (1 :| [2,3]) == 1 :| [0,2,0,3]

Interrupts the current wait of the I/O manager if it is currently blocked. This instructs it to re-read how much it should wait and to process any pending events.

i

The interact function takes a function of type ByteString -> ByteString as its argument. The entire input from the standard input device is passed to this function as its argument, and the resulting string is output on the standard output device.

O(n) The intercalate function takes a ByteString and a list of ByteStrings and concatenates the list after interspersing the first argument between each element of the list.

O(n) The intersperse function takes a Word8 and a ByteString and `intersperses' that byte between the elements of the ByteString. It is analogous to the intersperse function on Lists.

O(n) The intersperse function takes a Char and a ByteString and `intersperses' that Char between the elements of the ByteString. It is analogous to the intersperse function on Lists.

The intersperse function takes a Word8 and a ByteString and `intersperses' that byte between the elements of the ByteString. It is analogous to the intersperse function on Lists.

O(n) The intercalate function takes a ShortByteString and a list of ShortByteStrings and concatenates the list after interspersing the first argument between each element of the list.

O(n) The intercalate function takes a Text and a list of Texts and concatenates the list after interspersing the first argument between each element of the list. Example:

>>> T.intercalate "NI!" ["We", "seek", "the", "Holy", "Grail"]
"WeNI!seekNI!theNI!HolyNI!Grail"

O(n) The intersperse function takes a character and places it between the characters of a Text. Example:

>>> T.intersperse '.' "SHIELD"
"S.H.I.E.L.D"

Performs replacement on invalid scalar values.

The interact function takes a function of type Text -> Text as its argument. The entire input from the standard input device is passed to this function as its argument, and the resulting string is output on the standard output device.

intercalate str strs inserts the stream str in between the streams strs and concatenates the result. Properties

intercalate s = concat . intersperse s

O(n) Take a character and place it between each of the characters of a 'Stream Char'. Properties

unstream . intersperse c . stream = intersperse c