Returns the new Hash formed by merging each of other_hashes into a copy of self.
Each argument in other_hashes must be a Hash.
With arguments and no block:
Returns the new Hash object formed by merging each successive Hash in other_hashes into self.
Each new-key entry is added at the end.
Each duplicate-key entry’s value overwrites the previous value.
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h.merge(h1, h2) # => {:foo=>0, :bar=>4, :baz=>2, :bat=>6, :bam=>5}
With arguments and a block:
Returns a new Hash object that is the merge of self and each given hash.
The given hashes are merged left to right.
Each new-key entry is added at the end.
For each duplicate key:
Calls the block with the key and the old and new values.
The block’s return value becomes the new value for the entry.
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h3 = h.merge(h1, h2) { |key, old_value, new_value| old_value + new_value } h3 # => {:foo=>0, :bar=>5, :baz=>2, :bat=>9, :bam=>5}
With no arguments:
Returns a copy of self.
The block, if given, is ignored.
Example:
h = {foo: 0, bar: 1, baz: 2} h.merge # => {:foo=>0, :bar=>1, :baz=>2} h1 = h.merge { |key, old_value, new_value| raise 'Cannot happen' } h1 # => {:foo=>0, :bar=>1, :baz=>2}
Returns a new Array object that is a 1-dimensional flattening of self.
By default, nested Arrays are not flattened:
h = {foo: 0, bar: [:bat, 3], baz: 2} h.flatten # => [:foo, 0, :bar, [:bat, 3], :baz, 2]
Takes the depth of recursive flattening from Integer argument level:
h = {foo: 0, bar: [:bat, [:baz, [:bat, ]]]} h.flatten(1) # => [:foo, 0, :bar, [:bat, [:baz, [:bat]]]] h.flatten(2) # => [:foo, 0, :bar, :bat, [:baz, [:bat]]] h.flatten(3) # => [:foo, 0, :bar, :bat, :baz, [:bat]] h.flatten(4) # => [:foo, 0, :bar, :bat, :baz, :bat]
When level is negative, flattens all nested Arrays:
h = {foo: 0, bar: [:bat, [:baz, [:bat, ]]]} h.flatten(-1) # => [:foo, 0, :bar, :bat, :baz, :bat] h.flatten(-2) # => [:foo, 0, :bar, :bat, :baz, :bat]
When level is zero, returns the equivalent of to_a :
h = {foo: 0, bar: [:bat, 3], baz: 2} h.flatten(0) # => [[:foo, 0], [:bar, [:bat, 3]], [:baz, 2]] h.flatten(0) == h.to_a # => true
Returns a copy of self with all nil-valued entries removed:
h = {foo: 0, bar: nil, baz: 2, bat: nil} h1 = h.compact h1 # => {:foo=>0, :baz=>2}
Returns self with all its nil-valued entries removed (in place):
h = {foo: 0, bar: nil, baz: 2, bat: nil} h.compact! # => {:foo=>0, :baz=>2}
Returns nil if no entries were removed.
Returns true if key is a key in self, otherwise false.
Adds to ENV each key/value pair in the given hash; returns ENV:
ENV.replace('foo' => '0', 'bar' => '1') ENV.merge!('baz' => '2', 'bat' => '3') # => {"bar"=>"1", "bat"=>"3", "baz"=>"2", "foo"=>"0"}
Deletes the ENV entry for a hash value that is nil:
ENV.merge!('baz' => nil, 'bat' => nil) # => {"bar"=>"1", "foo"=>"0"}
For an already-existing name, if no block given, overwrites the ENV value:
ENV.merge!('foo' => '4') # => {"bar"=>"1", "foo"=>"4"}
For an already-existing name, if block given, yields the name, its ENV value, and its hash value; the block’s return value becomes the new name:
ENV.merge!('foo' => '5') { |name, env_val, hash_val | env_val + hash_val } # => {"bar"=>"1", "foo"=>"45"}
Raises an exception if a name or value is invalid (see Invalid Names and Values);
ENV.replace('foo' => '0', 'bar' => '1') ENV.merge!('foo' => '6', :bar => '7', 'baz' => '9') # Raises TypeError (no implicit conversion of Symbol into String) ENV # => {"bar"=>"1", "foo"=>"6"} ENV.merge!('foo' => '7', 'bar' => 8, 'baz' => '9') # Raises TypeError (no implicit conversion of Integer into String) ENV # => {"bar"=>"1", "foo"=>"7"}
Raises an exception if the block returns an invalid name: (see Invalid Names and Values):
ENV.merge!('bat' => '8', 'foo' => '9') { |name, env_val, hash_val | 10 } # Raises TypeError (no implicit conversion of Integer into String) ENV # => {"bar"=>"1", "bat"=>"8", "foo"=>"7"}
Note that for the exceptions above, hash pairs preceding an invalid name or value are processed normally; those following are ignored.
Adds to ENV each key/value pair in the given hash; returns ENV:
ENV.replace('foo' => '0', 'bar' => '1') ENV.merge!('baz' => '2', 'bat' => '3') # => {"bar"=>"1", "bat"=>"3", "baz"=>"2", "foo"=>"0"}
Deletes the ENV entry for a hash value that is nil:
ENV.merge!('baz' => nil, 'bat' => nil) # => {"bar"=>"1", "foo"=>"0"}
For an already-existing name, if no block given, overwrites the ENV value:
ENV.merge!('foo' => '4') # => {"bar"=>"1", "foo"=>"4"}
For an already-existing name, if block given, yields the name, its ENV value, and its hash value; the block’s return value becomes the new name:
ENV.merge!('foo' => '5') { |name, env_val, hash_val | env_val + hash_val } # => {"bar"=>"1", "foo"=>"45"}
Raises an exception if a name or value is invalid (see Invalid Names and Values);
ENV.replace('foo' => '0', 'bar' => '1') ENV.merge!('foo' => '6', :bar => '7', 'baz' => '9') # Raises TypeError (no implicit conversion of Symbol into String) ENV # => {"bar"=>"1", "foo"=>"6"} ENV.merge!('foo' => '7', 'bar' => 8, 'baz' => '9') # Raises TypeError (no implicit conversion of Integer into String) ENV # => {"bar"=>"1", "foo"=>"7"}
Raises an exception if the block returns an invalid name: (see Invalid Names and Values):
ENV.merge!('bat' => '8', 'foo' => '9') { |name, env_val, hash_val | 10 } # Raises TypeError (no implicit conversion of Integer into String) ENV # => {"bar"=>"1", "bat"=>"8", "foo"=>"7"}
Note that for the exceptions above, hash pairs preceding an invalid name or value are processed normally; those following are ignored.
Returns the count of environment variables:
ENV.replace('foo' => '0', 'bar' => '1') ENV.length # => 2 ENV.size # => 2
Returns true if there is an environment variable with the given name:
ENV.replace('foo' => '0', 'bar' => '1') ENV.include?('foo') # => true
Returns false if name is a valid String and there is no such environment variable:
ENV.include?('baz') # => false
Returns false if name is the empty String or is a String containing character '=':
ENV.include?('') # => false ENV.include?('=') # => false
Raises an exception if name is a String containing the NUL character "\0":
ENV.include?("\0") # Raises ArgumentError (bad environment variable name: contains null byte)
Raises an exception if name has an encoding that is not ASCII-compatible:
ENV.include?("\xa1\xa1".force_encoding(Encoding::UTF_16LE)) # Raises ArgumentError (bad environment variable name: ASCII incompatible encoding: UTF-16LE)
Raises an exception if name is not a String:
ENV.include?(Object.new) # TypeError (no implicit conversion of Object into String)
Reads at most maxlen bytes from the ARGF stream.
If the optional outbuf argument is present, it must reference a String, which will receive the data. The outbuf will contain only the received data after the method call even if it is not empty at the beginning.
It raises EOFError on end of ARGF stream. Since ARGF stream is a concatenation of multiple files, internally EOF is occur for each file. ARGF.readpartial returns empty strings for EOFs except the last one and raises EOFError for the last one.
Sets optional filename and line number that will be used in ERB code evaluation and error reporting. See also filename= and lineno=
erb = ERB.new('<%= some_x %>') erb.render # undefined local variable or method `some_x' # from (erb):1 erb.location = ['file.erb', 3] # All subsequent error reporting would use new location erb.render # undefined local variable or method `some_x' # from file.erb:4
Returns true if the ipaddr is a private address. IPv4 addresses in 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 as defined in RFC 1918 and IPv6 Unique Local Addresses in fc00::/7 as defined in RFC 4193 are considered private. Private IPv4 addresses in the IPv4-mapped IPv6 address range are also considered private.
Returns true if the log level allows entries with severity Logger::FATAL to be written, false otherwise. See Log Level.
Sets the log level to Logger::FATAL. See Log Level.
Equivalent to calling add with severity Logger::FATAL.
Initializes a new instance and evaluates the optional block in context of the instance. Arguments args are passed to new, see there for description of parameters.
This method is deprecated, its behavior corresponds to the older new method.
Parses command line arguments argv in order when environment variable POSIXLY_CORRECT is set, and in permutation mode otherwise. When optional into keyword argument is provided, the parsed option values are stored there via []= method (so it can be Hash, or OpenStruct, or other similar object).
Same as parse, but removes switches destructively. Non-option arguments remain in argv.
Return candidates for word.
Parses environment variable env or its uppercase with splitting like a shell.
env defaults to the basename of the program.
Returns an array of member names of the data class:
Measure = Data.define(:amount, :unit) Measure.members # => [:amount, :unit]
Returns the member names from self as an array:
Measure = Data.define(:amount, :unit) distance = Measure[10, 'km'] distance.members #=> [:amount, :unit]
Returns a shallow copy of self — the instance variables of self are copied, but not the objects they reference.
If the method is supplied any keyword arguments, the copy will be created with the respective field values updated to use the supplied keyword argument values. Note that it is an error to supply a keyword that the Data class does not have as a member.
Point = Data.define(:x, :y) origin = Point.new(x: 0, y: 0) up = origin.with(x: 1) right = origin.with(y: 1) up_and_right = up.with(y: 1) p origin # #<data Point x=0, y=0> p up # #<data Point x=1, y=0> p right # #<data Point x=0, y=1> p up_and_right # #<data Point x=1, y=1> out = origin.with(z: 1) # ArgumentError: unknown keyword: :z some_point = origin.with(1, 2) # ArgumentError: expected keyword arguments, got positional arguments
Returns size of the match array:
m = /(.)(.)(\d+)(\d)/.match("THX1138.") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8"> m.size # => 5
Returns the matched substring corresponding to the given argument.
When non-negative argument n is given, returns the matched substring for the nth match:
m = /(.)(.)(\d+)(\d)(\w)?/.match("THX1138.") # => #<MatchData "HX1138" 1:"H" 2:"X" 3:"113" 4:"8" 5:nil> m.match(0) # => "HX1138" m.match(4) # => "8" m.match(5) # => nil
When string or symbol argument name is given, returns the matched substring for the given name:
m = /(?<foo>.)(.)(?<bar>.+)/.match("hoge") # => #<MatchData "hoge" foo:"h" bar:"ge"> m.match('foo') # => "h" m.match(:bar) # => "ge"