Module BatSubstring


module BatSubstring: sig .. end
Substring.t is the type of substrings of a basestring, an efficient representation of a piece of a string.

A substring (s,i,n) is valid if 0 <= i <= i+n <= size s, or equivalently, 0 <= i and 0 <= n and i+n <= size s.

A valid substring (s, i, n) represents the string si...i+n-1.

Invariant in the implementation: Any value of type Substring.t is valid.


type t 
Substring.t is the type of substrings of a basestring, an efficient representation of a piece of a string.

A substring (s,i,n) is valid if 0 <= i <= i+n <= size s, or equivalently, 0 <= i and 0 <= n and i+n <= size s.

A valid substring (s, i, n) represents the string si...i+n-1.

Invariant in the implementation: Any value of type Substring.t is valid.

val empty : unit -> t
val to_string : t -> string
string sus is the string si..i+n-1 represented by sus = (s, i, n).
val of_string : string -> t
val make : int -> char -> t
val create : int -> t
val of_input : BatIO.input -> t
val substring : string -> int -> int -> t
substring s o l returns a substring with base-string s, offset o and length l. Arguments are checked for validity

substring(s, i, n) creates the substring (s, i, n), consisting of the substring of s with length n starting at i. Raises Inavlid_argument if i<0 or n<0 or i+n > size s. Equivalent to extract(s, i, SOME n).

val extract : string -> int -> int option -> t
extract(s, i, NONE) creates the substring (s, i, size s-i) consisting of the tail of s starting at i. Raises Invalid_argument if i<0 or i > size s.

extract(s, i, SOME n) creates the substring (s, i, n), consisting of the substring of s with length n starting at i. Raises Invalid_argument if i<0 or n<0 or i+n > size s.

val all : string -> t
all s is the substring (s, 0, size s).
val base : t -> string * int * int
base sus is the concrete triple (s, i, n), where sus = (s, i, n).
val is_empty : t -> bool
isEmpty (s, i, n) true if the substring is empty (that is, n = 0).
val getc : t -> (char * t) option
getc sus returns SOME(c, rst) where c is the first character and rst the remainder of sus, if sus is non-empty; otherwise returns NONE.
val first : t -> char option
first sus returns SOME c where c is the first character in sus, if sus is non-empty; otherwise returns NONE.
val triml : int -> t -> t
triml k sus returns sus less its leftmost k characters; or the empty string at the end of sus if it has less than k characters. if k < 0, even in the partial application triml(k).
val trimr : int -> t -> t
trimr k sus returns sus less its rightmost k characters; or the empty string at the beginning of sus if it has less than k characters. Raises Invalid_argument if k < 0, even in the partial application triml(k).
val get : int -> t -> char
sub (sus, k) returns the k'th character of the substring; that is, s(i+k) where sus = (s, i, n). Raises Invalid_argument if k<0 or k>=n.
val size : t -> int
size (s, i, n) returns the size of the substring, that is, n.
val slice : t -> int -> int option -> t
slice (sus, i', NONE) returns the substring (s, i+i', n-i'), where sus = (s, i, n). Raises Invalid_argument if i' < 0 or i' > n.

slice (sus, i', SOME n') returns the substring (s, i+i', n'), where sus = (s, i, n). Raises Invalid_argument if i' < 0 or n' < 0 or i'+n' >= n.

val concat : t list -> string
concat suss returns a string consisting of the concatenation of the substrings. Equivalent to String.concat (List.map string suss).
val explode : t -> char list
explode sus returns the list of characters of sus, that is, s(i), s(i+1), ..., s(i+n-1) where sus = (s, i, n). Equivalent to String.explode(string ss).
val is_prefix : string -> t -> bool
isPrefix s1 s2 is true if s1 is a prefix of s2. That is, if there exists a string t such that string s1 ^ t = string s2.
val compare : t -> t -> int
compare (sus1, sus2) performs lexicographic comparison, using the standard ordering Char.compare on the characters. Returns LESS, EQUAL, or GREATER, according as sus1 is less than, equal to, or greater than sus2. Equivalent to, but more efficient than, String.compare(string sus1, string sus2).
val dropl : (char -> bool) -> t -> t
dropl p sus drops the longest prefix (left substring) of sus all of whose characters satisfy predicate p. If all characters do, it returns the empty substring (s, i+n, 0) where sus = (s, i, n).
val dropr : (char -> bool) -> t -> t
dropr p sus drops the longest suffix (right substring) of sus all of whose characters satisfy predicate p. If all characters do, it returns the empty substring (s, i, 0) where sus = (s, i, n).
val takel : (char -> bool) -> t -> t
takel p sus returns the longest prefix (left substring) of sus all of whose characters satisfy predicate p. That is, if the left-most character does not satisfy p, returns the empty (s, i, 0) where sus = (s, i, n).
val taker : (char -> bool) -> t -> t
taker p sus returns the longest suffix (right substring) of sus all of whose characters satisfy predicate p. That is, if the right-most character satisfies p, returns the empty (s, i+n, 0) where sus = (s, i, n).

Let p be a predicate and xxxxfyyyyfzzzz a string where all characters in xxxx and zzzz satisfy p, and f a is character not satisfying p. Then

sus = xxxxfyyyyfzzzz sus = xxxxzzzz ------------------------------------------------------ dropl p sus = fyyyyfzzzz dropr p sus = xxxxfyyyyf takel p sus = xxxx xxxxzzzz taker p sus = zzzz xxxxzzzz

It also holds that concattakel p sus, dropl p sus = string sus concatdropr p sus, taker p sus = string sus

val splitl : (char -> bool) -> t -> t * t
splitl p sus splits sus into a pair (sus1, sus2) of substrings where sus1 is the longest prefix (left substring) all of whose characters satisfy p, and sus2 is the rest. That is, sus2 begins with the leftmost character not satisfying p. Disregarding sideeffects, we have: splitl p sus = (takel p sus, dropl p sus).
val splitr : (char -> bool) -> t -> t * t
splitr p sus splits sus into a pair (sus1, sus2) of substrings where sus2 is the longest suffix (right substring) all of whose characters satisfy p, and sus1 is the rest. That is, sus1 ends with the rightmost character not satisfying p. Disregarding sideeffects, we have: splitr p sus = (dropr p sus, taker p sus)
val split_at : int -> t -> t * t
splitAt (sus, k) returns the pair (sus1, sus2) of substrings, where sus1 contains the first k characters of sus, and sus2 contains the rest. Raises Invalid_argument if k < 0 or k > size sus.
val span : t -> t -> t
span (sus1, sus2) returns a substring spanning from the start of sus1 to the end of sus2, provided this is well-defined: sus1 and sus2 must have the same underlying string, and the start of sus1 must not be to the right of the end of sus2; otherwise raises Span.

More precisely, if base(sus1) = (s,i,n) and base(sus2) = (s',i',n') and s = s' and i <= i'+n', then base(join(sus1, sus2)) = (s, i, i'+n'-i). This may be used to compute `span', `union', and `intersection'.

val translate : (char -> char) -> t -> string
translate f sus applies f to every character of sus, from left to right, and returns the concatenation of the results. Raises Size if the sum of their sizes is greater than String.maxSize. Equivalent to String.concat(List.map f (explode sus)).
val tokens : (char -> bool) -> t -> t list
tokens p sus returns the list of tokens in sus, from left to right, where a token is a non-empty maximal substring of sus not containing any delimiter, and a delimiter is a character satisfying p.
val fields : (char -> bool) -> t -> t list
fields p sus returns the list of fields in sus, from left to right, where a field is a (possibly empty) maximal substring of sus not containing any delimiter, and a delimiter is a character satisfying p.

Two tokens may be separated by more than one delimiter, whereas two fields are separated by exactly one delimiter. If the only delimiter is the character #"|", then "abc||def" contains two tokens: "abc" and "def" "abc||def" contains three fields: "abc" and "" and "def"

val fold_left : ('a -> char -> 'a) -> 'a -> t -> 'a
foldl f e sus folds f over sus from left to right. That is, evaluates f(si+n-1, f( ... f(si+1, f(si % e)) ...)) tail-recursively, where sus = (s, i, n). Equivalent to List.foldl f e (explode sus).
val fold_right : (char -> 'a -> 'a) -> t -> 'a -> 'a
foldr f e sus folds f over sus from right to left. That is, evaluates f(si, f(si+1, f(... f(si+n-1 % e) ...))) tail-recursively, where sus = (s, i, n). Equivalent to List.foldr f e (explode sus).
val iter : (char -> unit) -> t -> unit
iter f sus applies f to all characters of sus, from left to right. Equivalent to List.app f (explode sus).
val trim : t -> t
removes whitespace from left and right ends of input
val split_on_char : char -> t -> t list
split_on_char c ss returns substrings of input ss as divided by c
val split_on_pipe : t -> t list
val split_on_dot : t -> t list
val split_on_comma : t -> t list
val split_on_slash : t -> t list