.TH "String" 3o 2012-06-26 OCamldoc "OCaml library"
.SH NAME
String \- String operations.
.SH Module
Module   String
.SH Documentation
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Module
.BI "String"
 : 
.B sig  end

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String operations\&.
Given a string 
.B s
of length 
.B l
, we call character number in 
.B s
the index of a character in 
.B s
\&.  Indexes start at 
.B 0
, and we will
call a character number valid in 
.B s
if it falls within the range
.B [0\&.\&.\&.l\-1]
\&. A position is the point between two characters or at
the beginning or end of the string\&.  We call a position valid
in 
.B s
if it falls within the range 
.B [0\&.\&.\&.l]
\&. Note that character
number 
.B n
is between positions 
.B n
and 
.B n+1
\&.
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Two parameters 
.B start
and 
.B len
are said to designate a valid
substring of 
.B s
if 
.B len >= 0
and 
.B start
and 
.B start+len
are
valid positions in 
.B s
\&.
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.I val length 
: 
.B string -> int
.sp
Return the length (number of characters) of the given string\&.
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.sp

.I val get 
: 
.B string -> int -> char
.sp

.B String\&.get s n
returns character number 
.B n
in string 
.B s
\&.
You can also write 
.B s\&.[n]
instead of 
.B String\&.get s n
\&.
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Raise 
.B Invalid_argument
if 
.B n
not a valid character number in 
.B s
\&.
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.I val set 
: 
.B string -> int -> char -> unit
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.B String\&.set s n c
modifies string 
.B s
in place,
replacing the character number 
.B n
by 
.B c
\&.
You can also write 
.B s\&.[n] <\- c
instead of 
.B String\&.set s n c
\&.
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Raise 
.B Invalid_argument
if 
.B n
is not a valid character number in 
.B s
\&.
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.I val create 
: 
.B int -> string
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.B String\&.create n
returns a fresh string of length 
.B n
\&.
The string initially contains arbitrary characters\&.
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Raise 
.B Invalid_argument
if 
.B n < 0
or 
.B n > 
.B Sys\&.max_string_length
\&.
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.sp

.I val make 
: 
.B int -> char -> string
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.B String\&.make n c
returns a fresh string of length 
.B n
,
filled with the character 
.B c
\&.
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Raise 
.B Invalid_argument
if 
.B n < 0
or 
.B n > 
.B Sys\&.max_string_length
\&.
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.sp

.I val copy 
: 
.B string -> string
.sp
Return a copy of the given string\&.
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.sp

.I val sub 
: 
.B string -> int -> int -> string
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.B String\&.sub s start len
returns a fresh string of length 
.B len
,
containing the substring of 
.B s
that starts at position 
.B start
and
has length 
.B len
\&.
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Raise 
.B Invalid_argument
if 
.B start
and 
.B len
do not
designate a valid substring of 
.B s
\&.
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.sp

.I val fill 
: 
.B string -> int -> int -> char -> unit
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.B String\&.fill s start len c
modifies string 
.B s
in place,
replacing 
.B len
characters by 
.B c
, starting at 
.B start
\&.
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Raise 
.B Invalid_argument
if 
.B start
and 
.B len
do not
designate a valid substring of 
.B s
\&.
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.sp

.I val blit 
: 
.B string -> int -> string -> int -> int -> unit
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.B String\&.blit src srcoff dst dstoff len
copies 
.B len
characters
from string 
.B src
, starting at character number 
.B srcoff
, to
string 
.B dst
, starting at character number 
.B dstoff
\&. It works
correctly even if 
.B src
and 
.B dst
are the same string,
and the source and destination intervals overlap\&.
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Raise 
.B Invalid_argument
if 
.B srcoff
and 
.B len
do not
designate a valid substring of 
.B src
, or if 
.B dstoff
and 
.B len
do not designate a valid substring of 
.B dst
\&.
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.sp

.I val concat 
: 
.B string -> string list -> string
.sp

.B String\&.concat sep sl
concatenates the list of strings 
.B sl
,
inserting the separator string 
.B sep
between each\&.
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.sp

.I val iter 
: 
.B (char -> unit) -> string -> unit
.sp

.B String\&.iter f s
applies function 
.B f
in turn to all
the characters of 
.B s
\&.  It is equivalent to
.B f s\&.[0]; f s\&.[1]; \&.\&.\&.; f s\&.[String\&.length s \- 1]; ()
\&.
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.sp

.I val escaped 
: 
.B string -> string
.sp
Return a copy of the argument, with special characters
represented by escape sequences, following the lexical
conventions of Objective Caml\&.  If there is no special
character in the argument, return the original string itself,
not a copy\&.
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.sp

.I val index 
: 
.B string -> char -> int
.sp

.B String\&.index s c
returns the character number of the first
occurrence of character 
.B c
in string 
.B s
\&.
.sp
Raise 
.B Not_found
if 
.B c
does not occur in 
.B s
\&.
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.sp

.I val rindex 
: 
.B string -> char -> int
.sp

.B String\&.rindex s c
returns the character number of the last
occurrence of character 
.B c
in string 
.B s
\&.
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Raise 
.B Not_found
if 
.B c
does not occur in 
.B s
\&.
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.sp

.I val index_from 
: 
.B string -> int -> char -> int
.sp

.B String\&.index_from s i c
returns the character number of the
first occurrence of character 
.B c
in string 
.B s
after position 
.B i
\&.
.B String\&.index s c
is equivalent to 
.B String\&.index_from s 0 c
\&.
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Raise 
.B Invalid_argument
if 
.B i
is not a valid position in 
.B s
\&.
Raise 
.B Not_found
if 
.B c
does not occur in 
.B s
after position 
.B i
\&.
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.sp

.I val rindex_from 
: 
.B string -> int -> char -> int
.sp

.B String\&.rindex_from s i c
returns the character number of the
last occurrence of character 
.B c
in string 
.B s
before position 
.B i+1
\&.
.B String\&.rindex s c
is equivalent to
.B String\&.rindex_from s (String\&.length s \- 1) c
\&.
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Raise 
.B Invalid_argument
if 
.B i+1
is not a valid position in 
.B s
\&.
Raise 
.B Not_found
if 
.B c
does not occur in 
.B s
before position 
.B i+1
\&.
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.sp

.I val contains 
: 
.B string -> char -> bool
.sp

.B String\&.contains s c
tests if character 
.B c
appears in the string 
.B s
\&.
.sp

.sp

.I val contains_from 
: 
.B string -> int -> char -> bool
.sp

.B String\&.contains_from s start c
tests if character 
.B c
appears in 
.B s
after position 
.B start
\&.
.B String\&.contains s c
is equivalent to
.B String\&.contains_from s 0 c
\&.
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Raise 
.B Invalid_argument
if 
.B start
is not a valid position in 
.B s
\&.
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.sp

.I val rcontains_from 
: 
.B string -> int -> char -> bool
.sp

.B String\&.rcontains_from s stop c
tests if character 
.B c
appears in 
.B s
before position 
.B stop+1
\&.
.sp
Raise 
.B Invalid_argument
if 
.B stop < 0
or 
.B stop+1
is not a valid
position in 
.B s
\&.
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.sp

.I val uppercase 
: 
.B string -> string
.sp
Return a copy of the argument, with all lowercase letters
translated to uppercase, including accented letters of the ISO
Latin\-1 (8859\-1) character set\&.
.sp

.sp

.I val lowercase 
: 
.B string -> string
.sp
Return a copy of the argument, with all uppercase letters
translated to lowercase, including accented letters of the ISO
Latin\-1 (8859\-1) character set\&.
.sp

.sp

.I val capitalize 
: 
.B string -> string
.sp
Return a copy of the argument, with the first character set to uppercase\&.
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.sp

.I val uncapitalize 
: 
.B string -> string
.sp
Return a copy of the argument, with the first character set to lowercase\&.
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.sp
.I type t 
= 
.B string

.sp
An alias for the type of strings\&.
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.sp

.I val compare 
: 
.B t -> t -> int
.sp
The comparison function for strings, with the same specification as
.B Pervasives\&.compare
\&.  Along with the type 
.B t
, this function 
.B compare
allows the module 
.B String
to be passed as argument to the functors
.B Set\&.Make
and 
.B Map\&.Make
\&.
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