When invoked with a block, yield all permutations of elements of self; returns self. The order of permutations is indeterminate.
When a block and an in-range positive Integer argument n (0 < n <= self.size) are given, calls the block with all n-tuple permutations of self.
Example:
a = [0, 1, 2] a.permutation(2) {|permutation| p permutation }
Output:
[0, 1] [0, 2] [1, 0] [1, 2] [2, 0] [2, 1]
Another example:
a = [0, 1, 2] a.permutation(3) {|permutation| p permutation }
Output:
[0, 1, 2] [0, 2, 1] [1, 0, 2] [1, 2, 0] [2, 0, 1] [2, 1, 0]
When n is zero, calls the block once with a new empty Array:
a = [0, 1, 2] a.permutation(0) {|permutation| p permutation }
Output:
[]
When n is out of range (negative or larger than self.size), does not call the block:
a = [0, 1, 2] a.permutation(-1) {|permutation| fail 'Cannot happen' } a.permutation(4) {|permutation| fail 'Cannot happen' }
When a block given but no argument, behaves the same as a.permutation(a.size):
a = [0, 1, 2] a.permutation {|permutation| p permutation }
Output:
[0, 1, 2] [0, 2, 1] [1, 0, 2] [1, 2, 0] [2, 0, 1] [2, 1, 0]
Returns a new Enumerator if no block given:
a = [0, 1, 2] a.permutation # => #<Enumerator: [0, 1, 2]:permutation> a.permutation(2) # => #<Enumerator: [0, 1, 2]:permutation(2)>
With no argument, or if the argument is the same as the receiver, return the receiver. Otherwise, create a new exception object of the same class as the receiver, but with a message equal to string.to_str.
With no argument, or if the argument is the same as the receiver, return the receiver. Otherwise, create a new exception object of the same class as the receiver, but with a message equal to string.to_str.
Parse an HTTP query string into a hash of key=>value pairs.
params = CGI.parse("query_string") # {"name1" => ["value1", "value2", ...], # "name2" => ["value1", "value2", ...], ... }
Parses the given representation of date and time, and returns a hash of parsed elements.
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 ‘Date._strptime` or `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”, considers the year a 2-digit form and makes it full.
Date._parse('2001-02-03') #=> {:year=>2001, :mon=>2, :mday=>3}
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.
Parses the given representation of date and time, and creates a date 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 ‘Date.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”, considers the year a 2-digit form and makes it full.
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 ...>
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.
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.
Start parsing and returns the value of the root action.
Returns the type library version.
tlib = WIN32OLE_TYPELIB.new('Microsoft Excel 9.0 Object Library') puts tlib.version #-> "1.3"
Parses string or io using the specified options.
Argument string should be a String object; it will be put into a new StringIO object positioned at the beginning.
Argument io should be an IO object that is:
Open for reading; on return, the IO object will be closed.
Positioned at the beginning. To position at the end, for appending, use method CSV.generate. For any other positioning, pass a preset StringIO object instead.
Argument options: see Options for Parsing
headers Without {option headers} case.
These examples assume prior execution of:
string = "foo,0\nbar,1\nbaz,2\n" path = 't.csv' File.write(path, string)
With no block given, returns an Array of Arrays formed from the source.
Parse a String:
a_of_a = CSV.parse(string) a_of_a # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]
Parse an open File:
a_of_a = File.open(path) do |file| CSV.parse(file) end a_of_a # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]
With a block given, calls the block with each parsed row:
Parse a String:
CSV.parse(string) {|row| p row }
Output:
["foo", "0"] ["bar", "1"] ["baz", "2"]
Parse an open File:
File.open(path) do |file| CSV.parse(file) {|row| p row } end
Output:
["foo", "0"] ["bar", "1"] ["baz", "2"]
headers With {option headers} case.
These examples assume prior execution of:
string = "Name,Count\nfoo,0\nbar,1\nbaz,2\n" path = 't.csv' File.write(path, string)
With no block given, returns a CSV::Table object formed from the source.
Parse a String:
csv_table = CSV.parse(string, headers: ['Name', 'Count']) csv_table # => #<CSV::Table mode:col_or_row row_count:5>
Parse an open File:
csv_table = File.open(path) do |file| CSV.parse(file, headers: ['Name', 'Count']) end csv_table # => #<CSV::Table mode:col_or_row row_count:4>
With a block given, calls the block with each parsed row, which has been formed into a CSV::Row object:
Parse a String:
CSV.parse(string, headers: ['Name', 'Count']) {|row| p row }
Output:
# <CSV::Row "Name":"foo" "Count":"0"> # <CSV::Row "Name":"bar" "Count":"1"> # <CSV::Row "Name":"baz" "Count":"2">
Parse an open File:
File.open(path) do |file| CSV.parse(file, headers: ['Name', 'Count']) {|row| p row } end
Output:
# <CSV::Row "Name":"foo" "Count":"0"> # <CSV::Row "Name":"bar" "Count":"1"> # <CSV::Row "Name":"baz" "Count":"2">
Raises an exception if the argument is not a String object or IO object:
# Raises NoMethodError (undefined method `close' for :foo:Symbol) CSV.parse(:foo)
Returns an Array containing field converters; see Field Converters:
csv = CSV.new('') csv.converters # => [] csv.convert(:integer) csv.converters # => [:integer] csv.convert(proc {|x| x.to_s }) csv.converters
Returns revision information for the erb.rb module.
Returns true if this is a permutation matrix Raises an error if matrix is not square.
Returns the parameter information of this proc.
prc = lambda{|x, y=42, *other|} prc.parameters #=> [[:req, :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]]
Return the parameters definition of the method or block that the current hook belongs to. 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 = <<-EOT { "name": "Dave", "age" :40, "hats": [ "Cattleman's", "Panama", "Tophat" ] } EOT 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('')
Calls
parse(source, opts)
with source and possibly modified opts.
Differences from JSON.parse:
Option max_nesting, if not provided, defaults to false, which disables checking for nesting depth.
Option allow_nan, if not provided, defaults to true.
Parse a YAML string in yaml. Returns the Psych::Nodes::Document. filename is used in the exception message if a Psych::SyntaxError is raised.
Raises a Psych::SyntaxError when a YAML syntax error is detected.
Example:
Psych.parse("---\n - a\n - b") # => #<Psych::Nodes::Document:0x00> begin Psych.parse("--- `", filename: "file.txt") rescue Psych::SyntaxError => ex ex.file # => 'file.txt' ex.message # => "(file.txt): found character that cannot start any token" end
See Psych::Nodes for more information about YAML AST.
URI::parse(uri_str)
Creates one of the URI’s subclasses instance from the string.
URI::InvalidURIError
Raised if URI given is not a correct one.
require 'uri' uri = URI.parse("http://www.ruby-lang.org/") # => #<URI::HTTP http://www.ruby-lang.org/> uri.scheme # => "http" uri.host # => "www.ruby-lang.org"
It’s recommended to first ::escape the provided uri_str if there are any invalid URI characters.
The standard configuration object for gems.