package pgx
Library
Module
Module type
Parameter
Class
Class type
include module type of String
String.get s n
returns the character at index n
in string s
. You can also write s.[n]
instead of String.get s n
.
Raise Invalid_argument
if n
not a valid index in s
.
String.set s n c
modifies byte sequence s
in place, replacing the byte at index n
with c
. You can also write s.[n] <- c
instead of String.set s n c
.
Raise Invalid_argument
if n
is not a valid index in s
.
String.create n
returns a fresh byte sequence of length n
. The sequence is uninitialized and contains arbitrary bytes.
Raise Invalid_argument
if n < 0
or n >
Sys.max_string_length
.
String.make n c
returns a fresh string of length n
, filled with the character c
.
Raise Invalid_argument
if n < 0
or n >
Sys.max_string_length
.
String.sub s start len
returns a fresh string of length len
, containing the substring of s
that starts at position start
and has length len
.
Raise Invalid_argument
if start
and len
do not designate a valid substring of s
.
String.fill s start len c
modifies byte sequence s
in place, replacing len
bytes with c
, starting at start
.
Raise Invalid_argument
if start
and len
do not designate a valid range of s
.
Same as Bytes.blit_string
.
String.concat sep sl
concatenates the list of strings sl
, inserting the separator string sep
between each.
Raise Invalid_argument
if the result is longer than Sys.max_string_length
bytes.
String.iter f s
applies function f
in turn to all the characters of s
. It is equivalent to f s.[0]; f s.[1]; ...; f s.[String.length s - 1]; ()
.
Same as String.iter
, but the function is applied to the index of the element as first argument (counting from 0), and the character itself as second argument.
String.map f s
applies function f
in turn to all the characters of s
(in increasing index order) and stores the results in a new string that is returned.
String.mapi f s
calls f
with each character of s
and its index (in increasing index order) and stores the results in a new string that is returned.
Return a copy of the argument, without leading and trailing whitespace. The characters regarded as whitespace are: ' '
, '\012'
, '\n'
, '\r'
, and '\t'
. If there is neither leading nor trailing whitespace character in the argument, return the original string itself, not a copy.
Return a copy of the argument, with special characters represented by escape sequences, following the lexical conventions of OCaml. All characters outside the ASCII printable range (32..126) are escaped, as well as backslash and double-quote.
If there is no special character in the argument that needs escaping, return the original string itself, not a copy.
Raise Invalid_argument
if the result is longer than Sys.max_string_length
bytes.
The function Scanf.unescaped
is a left inverse of escaped
, i.e. Scanf.unescaped (escaped s) = s
for any string s
(unless escape s
fails).
String.index s c
returns the index of the first occurrence of character c
in string s
.
Raise Not_found
if c
does not occur in s
.
String.index_opt s c
returns the index of the first occurrence of character c
in string s
, or None
if c
does not occur in s
.
String.rindex s c
returns the index of the last occurrence of character c
in string s
.
Raise Not_found
if c
does not occur in s
.
String.rindex_opt s c
returns the index of the last occurrence of character c
in string s
, or None
if c
does not occur in s
.
String.index_from s i c
returns the index of the first occurrence of character c
in string s
after position i
. String.index s c
is equivalent to String.index_from s 0 c
.
Raise Invalid_argument
if i
is not a valid position in s
. Raise Not_found
if c
does not occur in s
after position i
.
String.index_from_opt s i c
returns the index of the first occurrence of character c
in string s
after position i
or None
if c
does not occur in s
after position i
.
String.index_opt s c
is equivalent to String.index_from_opt s 0 c
. Raise Invalid_argument
if i
is not a valid position in s
.
String.rindex_from s i c
returns the index of the last occurrence of character c
in string s
before position i+1
. String.rindex s c
is equivalent to String.rindex_from s (String.length s - 1) c
.
Raise Invalid_argument
if i+1
is not a valid position in s
. Raise Not_found
if c
does not occur in s
before position i+1
.
String.rindex_from_opt s i c
returns the index of the last occurrence of character c
in string s
before position i+1
or None
if c
does not occur in s
before position i+1
.
String.rindex_opt s c
is equivalent to String.rindex_from_opt s (String.length s - 1) c
.
Raise Invalid_argument
if i+1
is not a valid position in s
.
String.contains s c
tests if character c
appears in the string s
.
String.contains_from s start c
tests if character c
appears in s
after position start
. String.contains s c
is equivalent to String.contains_from s 0 c
.
Raise Invalid_argument
if start
is not a valid position in s
.
String.rcontains_from s stop c
tests if character c
appears in s
before position stop+1
.
Raise Invalid_argument
if stop < 0
or stop+1
is not a valid position in s
.
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.
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.
Return a copy of the argument, with the first character set to uppercase, using the ISO Latin-1 (8859-1) character set..
Return a copy of the argument, with the first character set to lowercase, using the ISO Latin-1 (8859-1) character set..
Return a copy of the argument, with all lowercase letters translated to uppercase, using the US-ASCII character set.
Return a copy of the argument, with all uppercase letters translated to lowercase, using the US-ASCII character set.
Return a copy of the argument, with the first character set to uppercase, using the US-ASCII character set.
Return a copy of the argument, with the first character set to lowercase, using the US-ASCII character set.
The comparison function for strings, with the same specification as Stdlib.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
.
String.split_on_char sep s
returns the list of all (possibly empty) substrings of s
that are delimited by the sep
character.
The function's output is specified by the following invariants:
- The list is not empty.
- Concatenating its elements using
sep
as a separator returns a string equal to the input (String.concat (String.make 1 sep) (String.split_on_char sep s) = s
). - No string in the result contains the
sep
character.
Iterators
Iterate on the string, in increasing index order. Modifications of the string during iteration will be reflected in the iterator.
Iterate on the string, in increasing order, yielding indices along chars