O(n) Adds a character to the front of a Stream Char.

O(n) Adds a character to the end of a stream.

O(n) Appends one Stream to the other.

O(1) Returns the first character of a Text, which must be non-empty. Subject to array fusion.

O(1) Returns the first character and remainder of a 'Stream Char', or Nothing if empty. Subject to array fusion.

O(n) Returns the last character of a 'Stream Char', which must be non-empty.

O(1) Returns all characters after the head of a Stream Char, which must be non-empty.

O(1) Returns all but the last character of a Stream Char, which must be non-empty.

O(1) Tests whether a Stream Char is empty or not.

O(n) Returns the number of characters in a text.

O(n) map f xs is the Stream Char obtained by applying f to each element of xs.

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

O(n) Convert a string to folded case. This function is mainly useful for performing caseless (or case insensitive) string comparisons.

A string x is a caseless match for a string y if and only if:

toCaseFold x == toCaseFold y

The result string may be longer than the input string, and may differ from applying toLower to the input string. For instance, the Armenian small ligature men now (U+FB13) is case folded to the bigram men now (U+0574 U+0576), while the micro sign (U+00B5) is case folded to the Greek small letter letter mu (U+03BC) instead of itself.

O(n) Convert a string to lower case, using simple case conversion. The result string may be longer than the input string. For instance, the Latin capital letter I with dot above (U+0130) maps to the sequence Latin small letter i (U+0069) followed by combining dot above (U+0307).

O(n) Convert a string to upper case, using simple case conversion. The result string may be longer than the input string. For instance, the German eszett (U+00DF) maps to the two-letter sequence SS.

foldl, applied to a binary operator, a starting value (typically the left-identity of the operator), and a Stream, reduces the Stream using the binary operator, from left to right.

A strict version of foldl.

foldl1 is a variant of foldl that has no starting value argument, and thus must be applied to non-empty Streams.

A strict version of foldl1.

foldr, applied to a binary operator, a starting value (typically the right-identity of the operator), and a stream, reduces the stream using the binary operator, from right to left.

foldr1 is a variant of foldr that has no starting value argument, and thus must be applied to non-empty streams. Subject to array fusion.

O(n) Concatenate a list of streams. Subject to array fusion.

Map a function over a stream that results in a stream and concatenate the results.

O(n) any p xs determines if any character in the stream xs satisifes the predicate p.

O(n) all p xs determines if all characters in the Text xs satisify the predicate p.

O(n) maximum returns the maximum value from a stream, which must be non-empty.

O(n) minimum returns the minimum value from a Text, which must be non-empty.

O(n) Like a combination of map and foldl. Applies a function to each element of a stream, passing an accumulating parameter from left to right, and returns a final stream.

Note: Unlike the version over lists, this function does not return a final value for the accumulator, because the nature of streams precludes it.

O(n), where n is the length of the result. The unfoldr function is analogous to the List unfoldr. unfoldr builds a stream from a seed value. The function takes the element and returns Nothing if it is done producing the stream or returns Just (a,b), in which case, a is the next Char in the string, and b is the seed value for further production.

O(n) Like unfoldr, unfoldrNI builds a stream from a seed value. However, the length of the result is limited by the first argument to unfoldrNI. This function is more efficient than unfoldr when the length of the result is known.

O(n) take n, applied to a stream, returns the prefix of the stream of length n, or the stream itself if n is greater than the length of the stream.

O(n) drop n, applied to a stream, returns the suffix of the stream of length n, or the empty stream if n is greater than the length of the stream.

takeWhile, applied to a predicate p and a stream, returns the longest prefix (possibly empty) of elements that satisfy p.

dropWhile p xs returns the suffix remaining after takeWhile p xs.

O(n) The isPrefixOf function takes two Streams and returns True iff the first is a prefix of the second.

O(n) elem is the stream membership predicate.

O(n) filter, applied to a predicate and a stream, returns a stream containing those characters that satisfy the predicate.

O(n) The find function takes a predicate and a stream, and returns the first element in matching the predicate, or Nothing if there is no such element.

O(n) Stream index (subscript) operator, starting from 0.

The findIndexI function takes a predicate and a stream and returns the index of the first element in the stream satisfying the predicate.

The findIndicesI function takes a predicate and a stream and returns all indices of the elements in the stream satisfying the predicate.

O(n) The elemIndexI function returns the index of the first element in the given stream which is equal to the query element, or Nothing if there is no such element.

O(n) The elemIndicesI function returns the index of every element in the given stream which is equal to the query element.

O(n) The count function returns the number of times the query element appears in the given stream.

zipWith generalises zip by zipping with the function given as the first argument, instead of a tupling function.