Removes leading whitespace from the receiver. Returns the altered receiver, or nil
if no change was made. See also String#rstrip!
and String#strip!
.
Refer to String#strip
for the definition of whitespace.
" hello ".lstrip! #=> "hello " "hello ".lstrip! #=> nil "hello".lstrip! #=> nil
Removes trailing whitespace from the receiver. Returns the altered receiver, or nil
if no change was made. See also String#lstrip!
and String#strip!
.
Refer to String#strip
for the definition of whitespace.
" hello ".rstrip! #=> " hello" " hello".rstrip! #=> nil "hello".rstrip! #=> nil
Each other_str
parameter defines a set of characters to count. The intersection of these sets defines the characters to count in str
. Any other_str
that starts with a caret ^
is negated. The sequence c1-c2
means all characters between c1 and c2. The backslash character \
can be used to escape ^
or -
and is otherwise ignored unless it appears at the end of a sequence or the end of a other_str
.
a = "hello world" a.count "lo" #=> 5 a.count "lo", "o" #=> 2 a.count "hello", "^l" #=> 4 a.count "ej-m" #=> 4 "hello^world".count "\\^aeiou" #=> 4 "hello-world".count "a\\-eo" #=> 4 c = "hello world\\r\\n" c.count "\\" #=> 2 c.count "\\A" #=> 0 c.count "X-\\w" #=> 3
Searches sep or pattern (regexp) in the string and returns the part before it, the match, and the part after it. If it is not found, returns two empty strings and str.
"hello".partition("l") #=> ["he", "l", "lo"] "hello".partition("x") #=> ["hello", "", ""] "hello".partition(/.l/) #=> ["h", "el", "lo"]
Searches sep or pattern (regexp) in the string from the end of the string, and returns the part before it, the match, and the part after it. If it is not found, returns two empty strings and str.
"hello".rpartition("l") #=> ["hel", "l", "o"] "hello".rpartition("x") #=> ["", "", "hello"] "hello".rpartition(/.l/) #=> ["he", "ll", "o"]
Returns the Encoding
object that represents the encoding of obj.
The first form returns a copy of str
transcoded to encoding encoding
. The second form returns a copy of str
transcoded from src_encoding to dst_encoding. The last form returns a copy of str
transcoded to Encoding.default_internal
.
By default, the first and second form raise Encoding::UndefinedConversionError
for characters that are undefined in the destination encoding, and Encoding::InvalidByteSequenceError
for invalid byte sequences in the source encoding. The last form by default does not raise exceptions but uses replacement strings.
The options
Hash
gives details for conversion and can have the following keys:
If the value is :replace
, encode
replaces invalid byte sequences in str
with the replacement character. The default is to raise the Encoding::InvalidByteSequenceError
exception
If the value is :replace
, encode
replaces characters which are undefined in the destination encoding with the replacement character. The default is to raise the Encoding::UndefinedConversionError
.
Sets the replacement string to the given value. The default replacement string is “uFFFD” for Unicode encoding forms, and “?” otherwise.
Sets the replacement string by the given object for undefined character. The object should be a Hash
, a Proc
, a Method
, or an object which has [] method. Its key is an undefined character encoded in the source encoding of current transcoder. Its value can be any encoding until it can be converted into the destination encoding of the transcoder.
The value must be :text
or :attr
. If the value is :text
encode
replaces undefined characters with their (upper-case hexadecimal) numeric character references. ‘&’, ‘<’, and ‘>’ are converted to “&”, “<”, and “>”, respectively. If the value is :attr
, encode
also quotes the replacement result (using ‘“’), and replaces ‘”’ with “"”.
Replaces LF (“n”) with CR (“r”) if value is true.
Replaces LF (“n”) with CRLF (“rn”) if value is true.
Replaces CRLF (“rn”) and CR (“r”) with LF (“n”) if value is true.
The first form transcodes the contents of str from str.encoding to encoding
. The second form transcodes the contents of str from src_encoding to dst_encoding. The options Hash
gives details for conversion. See String#encode
for details. Returns the string even if no changes were made.
provides a unified clone
operation, for REXML::XPathParser
to use across multiple Object
types
Returns an array with both numeric
and float
represented as Float
objects.
This is achieved by converting numeric
to a Float
.
1.2.coerce(3) #=> [3.0, 1.2] 2.5.coerce(1.1) #=> [1.1, 2.5]
Returns a string containing a representation of self
. As well as a fixed or exponential form of the float
, the call may return NaN
, Infinity
, and -Infinity
.
Returns a simpler approximation of the value (flt-|eps| <= result <= flt+|eps|). If the optional argument eps
is not given, it will be chosen automatically.
0.3.rationalize #=> (3/10) 1.333.rationalize #=> (1333/1000) 1.333.rationalize(0.01) #=> (4/3)
See also Float#to_r
.
Transfer control to another fiber, resuming it from where it last stopped or starting it if it was not resumed before. The calling fiber will be suspended much like in a call to Fiber.yield
. You need to require 'fiber'
before using this method.
The fiber which receives the transfer call is treats it much like a resume call. Arguments passed to transfer are treated like those passed to resume.
You cannot resume a fiber that transferred control to another one. This will cause a double resume error. You need to transfer control back to this fiber before it can yield and resume.
Example:
fiber1 = Fiber.new do puts "In Fiber 1" Fiber.yield end fiber2 = Fiber.new do puts "In Fiber 2" fiber1.transfer puts "Never see this message" end fiber3 = Fiber.new do puts "In Fiber 3" end fiber2.resume fiber3.resume
produces
In fiber 2 In fiber 1 In fiber 3
Returns fiber information string.
Return a string describing this Dir
object.
Returns true
if the named file is a directory, false
otherwise.
Deprecated method. Don’t use.
Returns a File::Stat
object for the named file (see File::Stat
).
File.stat("testfile").mtime #=> Tue Apr 08 12:58:04 CDT 2003
Same as File::stat
, but does not follow the last symbolic link. Instead, reports on the link itself.
File.symlink("testfile", "link2test") #=> 0 File.stat("testfile").size #=> 66 File.lstat("link2test").size #=> 8 File.stat("link2test").size #=> 66
Same as IO#stat
, but does not follow the last symbolic link. Instead, reports on the link itself.
File.symlink("testfile", "link2test") #=> 0 File.stat("testfile").size #=> 66 f = File.new("link2test") f.lstat.size #=> 8 f.stat.size #=> 66
Return true
if the named file exists.
file_name can be an IO
object.
“file exists” means that stat() or fstat() system call is successful.
Deprecated method. Don’t use.
Returns a string which represents the encoding for programmers.
Encoding::UTF_8.inspect #=> "#<Encoding:UTF-8>" Encoding::ISO_2022_JP.inspect #=> "#<Encoding:ISO-2022-JP (dummy)>"
Returns the list of loaded encodings.
Encoding.list #=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>, #<Encoding:ISO-2022-JP (dummy)>] Encoding.find("US-ASCII") #=> #<Encoding:US-ASCII> Encoding.list #=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>, #<Encoding:US-ASCII>, #<Encoding:ISO-2022-JP (dummy)>]