Returns a 3-element array of substrings of self.
Matches a pattern against self, scanning backwards from the end. The pattern is:
string_or_regexp itself, if it is a Regexp.
Regexp.quote(string_or_regexp), if string_or_regexp is a string.
If the pattern is matched, returns pre-match, last-match, post-match:
'hello'.rpartition('l') # => ["hel", "l", "o"] 'hello'.rpartition('ll') # => ["he", "ll", "o"] 'hello'.rpartition('h') # => ["", "h", "ello"] 'hello'.rpartition('o') # => ["hell", "o", ""] 'hello'.rpartition(/l+/) # => ["hel", "l", "o"] 'hello'.rpartition('') # => ["hello", "", ""] 'тест'.rpartition('т') # => ["тес", "т", ""] 'こんにちは'.rpartition('に') # => ["こん", "に", "ちは"]
If the pattern is not matched, returns two empty strings and a copy of self:
'hello'.rpartition('x') # => ["", "", "hello"]
Related: String#partition, String#split.
With a block given, returns an array of two arrays:
The first having those elements for which the block returns a truthy value.
The other having all other elements.
Examples:
p = (1..4).partition {|i| i.even? } p # => [[2, 4], [1, 3]] p = ('a'..'d').partition {|c| c < 'c' } p # => [["a", "b"], ["c", "d"]] h = {foo: 0, bar: 1, baz: 2, bat: 3} p = h.partition {|key, value| key.start_with?('b') } p # => [[[:bar, 1], [:baz, 2], [:bat, 3]], [[:foo, 0]]] p = h.partition {|key, value| value < 2 } p # => [[[:foo, 0], [:bar, 1]], [[:baz, 2], [:bat, 3]]]
With no block given, returns an Enumerator.
Related: Enumerable#group_by.
Return the value that should be dumped for the version option.
Returns garbage collector generation for the given object.
class B include ObjectSpace def foo trace_object_allocations do obj = Object.new p "Generation is #{allocation_generation(obj)}" end end end B.new.foo #=> "Generation is 3"
See ::trace_object_allocations for more information and examples.
Returns an integer whose bits show the options set in self.
The option bits are:
Regexp::IGNORECASE # => 1 Regexp::EXTENDED # => 2 Regexp::MULTILINE # => 4
Examples:
/foo/.options # => 0 /foo/i.options # => 1 /foo/x.options # => 2 /foo/m.options # => 4 /foo/mix.options # => 7
Note that additional bits may be set in the returned integer; these are maintained internally in self, are ignored if passed to Regexp.new, and may be ignored by the caller:
Returns the set of bits corresponding to the options used when creating this regexp (see Regexp::new for details). Note that additional bits may be set in the returned options: these are used internally by the regular expression code. These extra bits are ignored if the options are passed to Regexp::new:
r = /\xa1\xa2/e # => /\xa1\xa2/ r.source # => "\\xa1\\xa2" r.options # => 16 Regexp.new(r.source, r.options) # => /\xa1\xa2/
Returns a default parser
Returns an array of the string keyword names:
FileUtils.options.take(3) # => ["noop", "verbose", "force"]
The version of the Marshal format for your Ruby.
Iterates over permutations of the elements of self; the order of permutations is indeterminate.
With a block and an in-range positive integer argument count (0 < count <= self.size) given, calls the block with each permutation of self of size count; returns self:
a = [0, 1, 2] perms = [] a.permutation(1) {|perm| perms.push(perm) } perms # => [[0], [1], [2]] perms = [] a.permutation(2) {|perm| perms.push(perm) } perms # => [[0, 1], [0, 2], [1, 0], [1, 2], [2, 0], [2, 1]] perms = [] a.permutation(3) {|perm| perms.push(perm) } perms # => [[0, 1, 2], [0, 2, 1], [1, 0, 2], [1, 2, 0], [2, 0, 1], [2, 1, 0]]
When count is zero, calls the block once with a new empty array:
perms = [] a.permutation(0) {|perm| perms.push(perm) } perms # => [[]]
When count is out of range (negative or larger than self.size), does not call the block:
a.permutation(-1) {|permutation| fail 'Cannot happen' } a.permutation(4) {|permutation| fail 'Cannot happen' }
With no block given, returns a new Enumerator.
Related: Methods for Iterating.
Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
With message nil, returns self:
x0 = StandardError.new('Boom') # => #<StandardError: Boom> x1 = x0.exception # => #<StandardError: Boom> x0.__id__ == x1.__id__ # => true
With string-convertible object message (even the same as the original message), returns a new exception object whose class is the same as self, and whose message is the given message:
x1 = x0.exception('Boom') # => #<StandardError: Boom> x0..equal?(x1) # => false
Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
With message nil, returns self:
x0 = StandardError.new('Boom') # => #<StandardError: Boom> x1 = x0.exception # => #<StandardError: Boom> x0.__id__ == x1.__id__ # => true
With string-convertible object message (even the same as the original message), returns a new exception object whose class is the same as self, and whose message is the given message:
x1 = x0.exception('Boom') # => #<StandardError: Boom> x0..equal?(x1) # => false
Parse an HTTP query string into a hash of key=>value pairs.
params = CGI.parse("query_string") # {"name1" => ["value1", "value2", ...], # "name2" => ["value1", "value2", ...], ... }
Note: This method recognizes many forms in string, but it is not a validator. For formats, see “Specialized Format Strings” in Formats for Dates and Times
If string does not specify a valid date, the result is unpredictable; consider using Date._strptime instead.
Returns a hash of values parsed from string:
Date._parse('2001-02-03') # => {:year=>2001, :mon=>2, :mday=>3}
If comp is true and the given year is in the range (0..99), the current century is supplied; otherwise, the year is taken as given:
Date._parse('01-02-03', true) # => {:year=>2001, :mon=>2, :mday=>3} Date._parse('01-02-03', false) # => {:year=>1, :mon=>2, :mday=>3}
See argument limit.
Related: Date.parse(returns a Date object).
Note: This method recognizes many forms in string, but it is not a validator. For formats, see “Specialized Format Strings” in Formats for Dates and Times If string does not specify a valid date, the result is unpredictable; consider using Date._strptime instead.
Returns a new Date object with values parsed from string:
Date.parse('2001-02-03') # => #<Date: 2001-02-03> Date.parse('20010203') # => #<Date: 2001-02-03> Date.parse('3rd Feb 2001') # => #<Date: 2001-02-03>
If comp is true and the given year is in the range (0..99), the current century is supplied; otherwise, the year is taken as given:
Date.parse('01-02-03', true) # => #<Date: 2001-02-03> Date.parse('01-02-03', false) # => #<Date: 0001-02-03>
See:
Argument start.
Argument limit.
Related: Date._parse (returns a hash).
Parses the given representation of date and time, and creates a DateTime object.
This method does not function as a validator. If the input string does not match valid formats strictly, you may get a cryptic result. Should consider to use DateTime.strptime instead of this method as possible.
If the optional second argument is true and the detected year is in the range “00” to “99”, makes it full.
DateTime.parse('2001-02-03T04:05:06+07:00') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...> DateTime.parse('20010203T040506+0700') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...> DateTime.parse('3rd Feb 2001 04:05:06 PM') #=> #<DateTime: 2001-02-03T16:05:06+00:00 ...>
Raise an ArgumentError when the string length is longer than limit. You can stop this check by passing limit: nil, but note that it may take a long time to parse.
Takes a string representation of a Time and attempts to parse it using a heuristic.
This method **does not** function as a validator. If the input string does not match valid formats strictly, you may get a cryptic result. Should consider to use Time.strptime instead of this method as possible.
require 'time' Time.parse("2010-10-31") #=> 2010-10-31 00:00:00 -0500
Any missing pieces of the date are inferred based on the current date.
require 'time' # assuming the current date is "2011-10-31" Time.parse("12:00") #=> 2011-10-31 12:00:00 -0500
We can change the date used to infer our missing elements by passing a second object that responds to mon, day and year, such as Date, Time or DateTime. We can also use our own object.
require 'time' class MyDate attr_reader :mon, :day, :year def initialize(mon, day, year) @mon, @day, @year = mon, day, year end end d = Date.parse("2010-10-28") t = Time.parse("2010-10-29") dt = DateTime.parse("2010-10-30") md = MyDate.new(10,31,2010) Time.parse("12:00", d) #=> 2010-10-28 12:00:00 -0500 Time.parse("12:00", t) #=> 2010-10-29 12:00:00 -0500 Time.parse("12:00", dt) #=> 2010-10-30 12:00:00 -0500 Time.parse("12:00", md) #=> 2010-10-31 12:00:00 -0500
If a block is given, the year described in date is converted by the block. This is specifically designed for handling two digit years. For example, if you wanted to treat all two digit years prior to 70 as the year 2000+ you could write this:
require 'time' Time.parse("01-10-31") {|year| year + (year < 70 ? 2000 : 1900)} #=> 2001-10-31 00:00:00 -0500 Time.parse("70-10-31") {|year| year + (year < 70 ? 2000 : 1900)} #=> 1970-10-31 00:00:00 -0500
If the upper components of the given time are broken or missing, they are supplied with those of now. For the lower components, the minimum values (1 or 0) are assumed if broken or missing. For example:
require 'time' # Suppose it is "Thu Nov 29 14:33:20 2001" now and # your time zone is EST which is GMT-5. now = Time.parse("Thu Nov 29 14:33:20 2001") Time.parse("16:30", now) #=> 2001-11-29 16:30:00 -0500 Time.parse("7/23", now) #=> 2001-07-23 00:00:00 -0500 Time.parse("Aug 31", now) #=> 2001-08-31 00:00:00 -0500 Time.parse("Aug 2000", now) #=> 2000-08-01 00:00:00 -0500
Since there are numerous conflicts among locally defined time zone abbreviations all over the world, this method is not intended to understand all of them. For example, the abbreviation “CST” is used variously as:
-06:00 in America/Chicago, -05:00 in America/Havana, +08:00 in Asia/Harbin, +09:30 in Australia/Darwin, +10:30 in Australia/Adelaide, etc.
Based on this fact, this method only understands the time zone abbreviations described in RFC 822 and the system time zone, in the order named. (i.e. a definition in RFC 822 overrides the system time zone definition.) The system time zone is taken from Time.local(year, 1, 1).zone and Time.local(year, 7, 1).zone. If the extracted time zone abbreviation does not match any of them, it is ignored and the given time is regarded as a local time.
ArgumentError is raised if Date._parse cannot extract information from date or if the Time class cannot represent specified date.
This method can be used as a fail-safe for other parsing methods as:
Time.rfc2822(date) rescue Time.parse(date) Time.httpdate(date) rescue Time.parse(date) Time.xmlschema(date) rescue Time.parse(date)
A failure of Time.parse should be checked, though.
You must require ‘time’ to use this method.
Parses the given Ruby program read from src. src must be a String or an IO or a object with a gets method.
Returns revision information for the erb.rb module.
Returns the parameter information of this proc. If the lambda keyword is provided and not nil, treats the proc as a lambda if true and as a non-lambda if false.
prc = proc{|x, y=42, *other|} prc.parameters #=> [[:opt, :x], [:opt, :y], [:rest, :other]] prc = lambda{|x, y=42, *other|} prc.parameters #=> [[:req, :x], [:opt, :y], [:rest, :other]] prc = proc{|x, y=42, *other|} prc.parameters(lambda: true) #=> [[:req, :x], [:opt, :y], [:rest, :other]] prc = lambda{|x, y=42, *other|} prc.parameters(lambda: false) #=> [[:opt, :x], [:opt, :y], [:rest, :other]]
Returns the parameter information of this method.
def foo(bar); end method(:foo).parameters #=> [[:req, :bar]] def foo(bar, baz, bat, &blk); end method(:foo).parameters #=> [[:req, :bar], [:req, :baz], [:req, :bat], [:block, :blk]] def foo(bar, *args); end method(:foo).parameters #=> [[:req, :bar], [:rest, :args]] def foo(bar, baz, *args, &blk); end method(:foo).parameters #=> [[:req, :bar], [:req, :baz], [:rest, :args], [:block, :blk]]
Returns the parameter information of this method.
def foo(bar); end method(:foo).parameters #=> [[:req, :bar]] def foo(bar, baz, bat, &blk); end method(:foo).parameters #=> [[:req, :bar], [:req, :baz], [:req, :bat], [:block, :blk]] def foo(bar, *args); end method(:foo).parameters #=> [[:req, :bar], [:rest, :args]] def foo(bar, baz, *args, &blk); end method(:foo).parameters #=> [[:req, :bar], [:req, :baz], [:rest, :args], [:block, :blk]]
Returns the parameter definitions of the method or block that the current hook belongs to. The format is the same as for Method#parameters.
Returns the Ruby objects created by parsing the given source.
Argument source contains the String to be parsed.
Argument opts, if given, contains a Hash of options for the parsing. See Parsing Options.
When source is a JSON array, returns a Ruby Array:
source = '["foo", 1.0, true, false, null]' ruby = JSON.parse(source) ruby # => ["foo", 1.0, true, false, nil] ruby.class # => Array
When source is a JSON object, returns a Ruby Hash:
source = '{"a": "foo", "b": 1.0, "c": true, "d": false, "e": null}' ruby = JSON.parse(source) ruby # => {"a"=>"foo", "b"=>1.0, "c"=>true, "d"=>false, "e"=>nil} ruby.class # => Hash
For examples of parsing for all JSON data types, see Parsing JSON.
Parses nested JSON objects:
source = <<~JSON { "name": "Dave", "age" :40, "hats": [ "Cattleman's", "Panama", "Tophat" ] } JSON ruby = JSON.parse(source) ruby # => {"name"=>"Dave", "age"=>40, "hats"=>["Cattleman's", "Panama", "Tophat"]}
Raises an exception if source is not valid JSON:
# Raises JSON::ParserError (783: unexpected token at ''): JSON.parse('')