Module BatString

module BatString: sig .. end

val is_empty : string -> bool

is_empty s returns true if s is the empty string, false otherwise.

Usually a tad faster than comparing s with "".

Example: if String.is_empty s then "(Empty)" else s

val init : int -> (int -> char) -> string

init l f returns the string of length l with the chars f 0 , f 1 , f 2 ... f (l-1).

Example: String.init 256 char_of_int

val enum : string -> char BatEnum.t

Conversions

Returns an enumeration of the characters of a string.

Example: String.enum se // (fun c -> not (is_bad_char c)) |> String.of_enum

val of_enum : char BatEnum.t -> string

Creates a string from a character enumeration.

Example: String.enum se // (fun c -> not (is_bad_char c)) |> String.of_enum

val backwards : string -> char BatEnum.t

Returns an enumeration of the characters of a string, from last to first.

Example: let rev s = String.backwards s |> String.of_enum

val of_backwards : char BatEnum.t -> string

Build a string from an enumeration, starting with last character, ending with first.

Example: let rev s = String.enum s |> String.of_backwards

val of_list : char list -> string

Converts a list of characters to a string.

Example: ['c'; 'h'; 'a'; 'r'; 's'] |> String.of_list

val to_list : string -> char list

Converts a string to the list of its characters.

Example: String.to_list "string" |> List.interleave ';' |> String.of_list = "s;t;r;i;n;g"

val of_int : int -> string

Returns the string representation of an int.

Example: String.of_int 56 = "56"

val of_float : float -> string

Returns the string representation of an float.

Example: String.of_float 1.246 = "1.246"

val of_char : char -> string

Returns a string containing one given character.

Example: String.of_char 's' = "s"

val to_int : string -> int

Returns the integer represented by the given string or raises Invalid_string if the string does not represent an integer. This follows OCaml's int literal rules, so "0x" prefixes hexadecimal integers, "0o" for octal and "0b" for binary. Underscores within the number are allowed for readability but ignored.

Example: String.to_int "8_480" = String.to_int "0x21_20"

val to_float : string -> float

Returns the float represented by the given string or raises Invalid_string if the string does not represent a float. Decimal points aren't required in the given string, as they are for float literals in OCaml, but otherwise the rules for float literals apply.

Example: String.of_float "12.34e-1" = String.of_float "1.234"

val map : (char -> char) -> string -> string

map f s returns a string where all characters c in s have been replaced by f c.

Example: String.map Char.uppercase "Five" = "FIVE" *

val fold_left : ('a -> char -> 'a) -> 'a -> string -> 'a

fold_left f a s is f (... (f (f a s.[0]) s.[1]) ...) s.[n-1]

Example: String.fold_left max "apples" = 's'

val fold_right : (char -> 'a -> 'a) -> string -> 'a -> 'a

fold_right f s b is f s.[0] (f s.[1] (... (f s.[n-1] b) ...))

Example: String.fold_right (fun a c -> if c = ' ' then a+1 else a) 0 s

val filter : (char -> bool) -> string -> string

filter f s returns a copy of string s in which only characters c such that f c = true remain.

Example: String.filter is_bad_char s

val filter_map : (char -> char option) -> string -> string

filter_map f s calls (f a0) (f a1).... (f an) where a0..an are the characters of s. It returns the string of characters ci such as f ai = Some ci (when f returns None, the corresponding element of s is discarded).

Example: String.filter_map (function 'a'-'z' as c -> Some c | _ -> None)

val iteri : (int -> char -> unit) -> string -> unit

String.iteri f s is equivalent to f 0 s.[0]; f 1 s.[1]; ...; f len s.[len] where len is length of string s.

Example: let pos = Array.make 256 0 in String.iteri (fun i c -> pos.(int_of_char c) <- i

val find : string -> string -> int

find s x returns the starting index of the first occurrence of string x within string s.

Note This implementation is optimized for short strings.
Raises Invalid_string if x is not a substring of s.

Example: String.find "foobarbaz" "bar" = 3

val find_from : string -> int -> string -> int

find_from s ofs x behaves as find s x but starts searching at offset ofs. find s x is equivalent to find_from s 0 x.

Example: String.find_from "foobarbaz" 4 "ba" = 6

val rfind : string -> string -> int

rfind s x returns the starting index of the last occurrence of string x within string s.

Note This implementation is optimized for short strings.
Raises Invalid_string if x is not a substring of s.

Example: String.rfind "foobarbaz" "ba" = 6

val rfind_from : string -> int -> string -> int

rfind_from s ofs x behaves as rfind s x but starts searching at offset ofs. rfind s x is equivalent to rfind_from s (String.length s - 1) x.

Example: String.rfind_from "foobarbaz" 6 "ba" = 6

val ends_with : string -> string -> bool

ends_with s x returns true if the string s is ending with x, false otherwise.

Example: String.ends_with "foobarbaz" "rbaz" = true

val starts_with : string -> string -> bool

starts_with s x returns true if s is starting with x, false otherwise.

Example: String.starts_with "foobarbaz" "fooz" = false

val exists : string -> string -> bool

exists str sub returns true if sub is a substring of str or false otherwise.

Example: String.exists "foobarbaz" "obar" = true

val lchop : string -> string

Returns the same string but without the first character. does nothing if the string is empty.

Example: String.lchop "Weeble" = "eeble"

val rchop : string -> string

Returns the same string but without the last character. does nothing if the string is empty.

Example: String.rchop "Weeble" = "Weebl"

val trim : string -> string

Returns the same string but without the leading and trailing whitespaces.

Example: String.trim " \t foo " = "foo"

val quote : string -> string

Add quotes around a string and escape any quote appearing in that string. This function is used typically when you need to generate source code from a string.

Examples: quote "foo" returns "\"foo\"" quote "\"foo\"" returns "\\\"foo\\\"" etc.

val left : string -> int -> string

left r len returns the string containing the len first characters of r

Example: String.left "Weeble" 4 = "Weeb"

val right : string -> int -> string

left r len returns the string containing the len last characters of r

Example: String.right "Weeble" 4 = "eble"

val head : string -> int -> string

as BatString.left

val tail : string -> int -> string

tail r pos returns the string containing all but the pos first characters of r

Example: String.tail "Weeble" 4 = "le"

val strip : ?chars:string -> string -> string

Returns the string without the chars if they are at the beginning or at the end of the string. By default chars are " \t\r\n".

Example: String.strip ~chars:" ,()" " boo() bar()" = "boo() bar"

val replace_chars : (char -> string) -> string -> string

replace_chars f s returns a string where all chars c of s have been replaced by the string returned by f c.

Example: String.replace_chars (function ' ' -> "(space)" | c -> c) "foo bar" = "foo(space)bar"

val replace : str:string -> sub:string -> by:string -> bool * string

replace ~str ~sub ~by returns a tuple constisting of a boolean and a string where the first occurrence of the string sub within str has been replaced by the string by. The boolean is true if a subtitution has taken place.

Example: String.replace "foobarbaz" "bar" "rab" = (true, "foorabbaz")

val repeat : string -> int -> string

repeat s n returns s ^ s ^ ... ^ s

Example: String.repeat "foo" 4 = "foofoofoofoo"

val split : string -> string -> string * string

split s sep splits the string s between the first occurrence of sep.
Raises Invalid_string if the separator is not found.

Example: String.split "abcabcabc" "bc" = ("a","abcabc")

val rsplit : string -> string -> string * string

rsplit s sep splits the string s between the last occurrence of sep.
Raises Invalid_string if the separator is not found.

Example: String.rsplit "abcabcabc" "bc" = ("abcabca","")

val nsplit : string -> string -> string list

nsplit s sep splits the string s into a list of strings which are separated by sep. nsplit "" _ returns the empty list.

Example: String.nsplit "abcabcabc" "bc" = ["a"; "a"; "a"; ""]

val join : string -> string list -> string

Same as concat

val slice : ?first:int -> ?last:int -> string -> string

slice ?first ?last s returns a "slice" of the string which corresponds to the characters s.[first], s.[first+1], ..., s[last-1]. Note that the character at index last is not included! If first is omitted it defaults to the start of the string, i.e. index 0, and if last is omitted is defaults to point just past the end of s, i.e. length s. Thus, slice s is equivalent to copy s.

Negative indexes are interpreted as counting from the end of the string. For example, slice ~last:(-2) s will return the string s, but without the last two characters.

This function never raises any exceptions. If the indexes are out of bounds they are automatically clipped.

Example: String.slice 1 (-3) " foo bar baz" = "foo bar "

val splice : string -> int -> int -> string -> string

String.splice s off len rep cuts out the section of s indicated by off and len and replaces it by rep

Negative indexes are interpreted as counting from the end of the string. If off+len is greater than length s, the end of the string is used, regardless of the value of len.

Example: String.splice "foo bar baz" 3 5 "XXX" = "fooXXXbaz"

val explode : string -> char list

explode s returns the list of characters in the string s.

Example: String.explode "foo" = ['f'; 'o'; 'o']

val implode : char list -> string

implode cs returns a string resulting from concatenating the characters in the list cs.

Example: String.implode ['b'; 'a'; 'r'] = "bar"

val compare : String.t -> String.t -> int

The comparison function for strings, with the same specification as Pervasives.compare. Along with the type t, this function compare allows the module String to be passed as argument to the functors Set.Make and Map.Make.

Example: String.compare "FOO" "bar" = -1 i.e. "FOO" < "bar"

val icompare : String.t -> String.t -> int

Compare two strings, case-insensitive.

Example: String.icompare "FOO" "bar" = 1 i.e. "foo" > "bar"

module IString: BatInterfaces.OrderedType  with type t = t

uses icompare as ordering function

val numeric_compare : String.t -> String.t -> int

Compare two strings, sorting "abc32def" before "abc210abc".

Algorithm: Ignore identical prefixes, if first character difference is numeric, parse the whole number as an int and compare.

Example: String.numeric_compare "xx32" "xx210" = -1

module NumString: BatInterfaces.OrderedType  with type t = t

uses numeric_compare as its ordering function

val print : 'a BatInnerIO.output -> string -> unit

Print a string.

Example: String.print stdout "foo\n"

val println : 'a BatInnerIO.output -> string -> unit

Print a string, end the line.

Example: String.println stdout "foo"

val print_quoted : 'a BatInnerIO.output -> string -> unit

Print a string, with quotes.

print_quoted stdout "foo" prints "foo" (with the quotes)

print_quoted stdout "\"bar\"" prints "\"bar\"" (with the quotes)

val t_printer : String.t BatValue_printer.t