From 84adefa331c4159d432d22840663c38f155cd4c1 Mon Sep 17 00:00:00 2001 From: Erlang/OTP Date: Fri, 20 Nov 2009 14:54:40 +0000 Subject: The R13B03 release. --- lib/stdlib/doc/src/string.xml | 415 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 415 insertions(+) create mode 100644 lib/stdlib/doc/src/string.xml (limited to 'lib/stdlib/doc/src/string.xml') diff --git a/lib/stdlib/doc/src/string.xml b/lib/stdlib/doc/src/string.xml new file mode 100644 index 0000000000..7ee38e496d --- /dev/null +++ b/lib/stdlib/doc/src/string.xml @@ -0,0 +1,415 @@ + + + + +
+ + 19962009 + Ericsson AB. All Rights Reserved. + + + The contents of this file are subject to the Erlang Public License, + Version 1.1, (the "License"); you may not use this file except in + compliance with the License. You should have received a copy of the + Erlang Public License along with this software. If not, it can be + retrieved online at http://www.erlang.org/. + + Software distributed under the License is distributed on an "AS IS" + basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + the License for the specific language governing rights and limitations + under the License. + + + + string + Robert Virding + Bjarne Dacker + 1 + Bjarne Däcker + + 96-09-28 + A + string.sgml +
+ string + String Processing Functions + +

This module contains functions for string processing.

+ + + + len(String) -> Length + Return the length of a string + + String = string() + Length = integer() + + +

Returns the number of characters in the string.

+ + + + equal(String1, String2) -> bool() + Test string equality + + String1 = String2 = string() + + +

Tests whether two strings are equal. Returns true if + they are, otherwise false.

+ + + + concat(String1, String2) -> String3 + Concatenate two strings + + String1 = String2 = String3 = string() + + +

Concatenates two strings to form a new string. Returns the + new string.

+ + + + chr(String, Character) -> Index + rchr(String, Character) -> Index + Return the index of the first/last occurrence ofCharacterin String + + String = string() + Character = char() + Index = integer() + + +

Returns the index of the first/last occurrence of + Character in String. 0 is returned if Character does not + occur.

+ + + + str(String, SubString) -> Index + rstr(String, SubString) -> Index + Find the index of a substring + + String = SubString = string() + Index = integer() + + +

Returns the position where the first/last occurrence of + SubString begins in String. 0 is returned if SubString + does not exist in String. + For example:

+ +> string:str(" Hello Hello World World ", "Hello World"). +8 + + + + span(String, Chars) -> Length + cspan(String, Chars) -> Length + Span characters at start of string + + String = Chars = string() + Length = integer() + + +

Returns the length of the maximum initial segment of + String, which consists entirely of characters from (not + from) Chars.

+

For example:

+ +> string:span("\\t abcdef", " \\t"). +5 +> string:cspan("\\t abcdef", " \\t"). +0 + + + + substr(String, Start) -> SubString + substr(String, Start, Length) -> Substring + Return a substring of String + + String = SubString = string() + Start = Length = integer() + + +

Returns a substring of String, starting at the + position Start, and ending at the end of the string or + at length Length.

+

For example:

+ +> substr("Hello World", 4, 5). +"lo Wo" + + + + tokens(String, SeparatorList) -> Tokens + Split string into tokens + + String = SeparatorList = string() + Tokens = [string()] + + +

Returns a list of tokens in String, separated by the + characters in SeparatorList.

+

For example:

+ +> tokens("abc defxxghix jkl", "x "). +["abc", "def", "ghi", "jkl"] + + + + join(StringList, Separator) -> String + Join a list of strings with separator + + StringList = [string()] + Separator = string() + + +

Returns a string with the elements of StringList + separated by the string in Seperator.

+

For example:

+ +> join(["one", "two", "three"], ", "). +"one, two, three" + + + + chars(Character, Number) -> String + chars(Character, Number, Tail) -> String + Returns a string consisting of numbers of characters + + Character = char() + Number = integer() + String = string() + + +

Returns a string consisting of Number of characters + Character. Optionally, the string can end with the + string Tail.

+ + + + copies(String, Number) -> Copies + Copy a string + + String = Copies = string() + Number = integer() + + +

Returns a string containing String repeated + Number times.

+ + + + words(String) -> Count + words(String, Character) -> Count + Count blank separated words + + String = string() + Character = char() + Count = integer() + + +

Returns the number of words in String, separated by + blanks or Character.

+

For example:

+ +> words(" Hello old boy!", $o). +4 + + + + sub_word(String, Number) -> Word + sub_word(String, Number, Character) -> Word + Extract subword + + String = Word = string() + Character = char() + Number = integer() + + +

Returns the word in position Number of String. + Words are separated by blanks or Characters.

+

For example:

+ +> string:sub_word(" Hello old boy !",3,$o). +"ld b" + + + + strip(String) -> Stripped + strip(String, Direction) -> Stripped + strip(String, Direction, Character) -> Stripped + Strip leading or trailing characters + + String = Stripped = string() + Direction = left | right | both + Character = char() + + +

Returns a string, where leading and/or trailing blanks or a + number of Character have been removed. + Direction can be left, right, or + both and indicates from which direction blanks are to be + removed. The function strip/1 is equivalent to + strip(String, both).

+

For example:

+ +> string:strip("...Hello.....", both, $.). +"Hello" + + + + left(String, Number) -> Left + left(String, Number, Character) -> Left + Adjust left end of string + + String = Left = string() + Character = char + Number = integer() + + +

Returns the String with the length adjusted in + accordance with Number. The left margin is + fixed. If the length(String) < Number, + String is padded with blanks or Characters.

+

For example:

+ +> string:left("Hello",10,$.). +"Hello....." + + + + right(String, Number) -> Right + right(String, Number, Character) -> Right + Adjust right end of string + + String = Right = string() + Character = char + Number = integer() + + +

Returns the String with the length adjusted in + accordance with Number. The right margin is + fixed. If the length of (String) < Number, + String is padded with blanks or Characters.

+

For example:

+ +> string:right("Hello", 10, $.). +".....Hello" + + + + centre(String, Number) -> Centered + centre(String, Number, Character) -> Centered + Center a string + + String = Centered = string() + Character = char + Number = integer() + + +

Returns a string, where String is centred in the + string and surrounded by blanks or characters. The resulting + string will have the length Number.

+ + + + sub_string(String, Start) -> SubString + sub_string(String, Start, Stop) -> SubString + Extract a substring + + String = SubString = string() + Start = Stop = integer() + + +

Returns a substring of String, starting at the + position Start to the end of the string, or to and + including the Stop position.

+

For example:

+ +sub_string("Hello World", 4, 8). +"lo Wo" + + + + to_float(String) -> {Float,Rest} | {error,Reason} + Returns a float whose text representation is the integers (ASCII values) in String. + + String = string() + Float = float() + Rest = string() + Reason = no_float | not_a_list + + +

Argument String is expected to start with a valid text + represented float (the digits being ASCII values). Remaining characters + in the string after the float are returned in Rest.

+

Example:

+ + > {F1,Fs} = string:to_float("1.0-1.0e-1"), + > {F2,[]} = string:to_float(Fs), + > F1+F2. + 0.9 + > string:to_float("3/2=1.5"). + {error,no_float} + > string:to_float("-1.5eX"). + {-1.5,"eX"} + + + + to_integer(String) -> {Int,Rest} | {error,Reason} + Returns an integer whose text representation is the integers (ASCII values) in String. + + String = string() + Int = integer() + Rest = string() + Reason = no_integer | not_a_list + + +

Argument String is expected to start with a valid text + represented integer (the digits being ASCII values). Remaining characters + in the string after the integer are returned in Rest.

+

Example:

+ + > {I1,Is} = string:to_integer("33+22"), + > {I2,[]} = string:to_integer(Is), + > I1-I2. + 11 + > string:to_integer("0.5"). + {0,".5"} + > string:to_integer("x=2"). + {error,no_integer} + + + + to_lower(String) -> Result + to_lower(Char) -> CharResult + to_upper(String) -> Result + to_upper(Char) -> CharResult + Convert case of string (ISO/IEC 8859-1) + + String = Result = string() + Char = CharResult = integer() + + +

The given string or character is case-converted. Note that + the supported character set is ISO/IEC 8859-1 (a.k.a. Latin 1), + all values outside this set is unchanged

+ + + + +
+ Notes +

Some of the general string functions may seem to overlap each + other. The reason for this is that this string package is the + combination of two earlier packages and all the functions of + both packages have been retained. +

+ +

Any undocumented functions in string should not be used.

+ +
+ + -- cgit v1.2.3