Search for the specifications that match the given dependency. The specifications in the returned array will be considered in reverse order, so the latest version ought to be last. @note This method should be ‘pure’, i.e. the return value should depend
only on the `dependency` parameter.
@param [Object] dependency @return [Array<Object>] the specifications that satisfy the given
`dependency`.
@return [Object] most up-to-date dependency in the possibility set
Filter’s a state’s possibilities to remove any that would (eventually) create a requirement in the conflict we’ve just rewound from @param [UnwindDetails] unwind_details details of the conflict just unwound from @return [void]
Adds this spec’s require paths to LOAD_PATH, in the proper location.
Returns self
.
Returns a new Array containing zero or more trailing elements of self
; does not modify self
.
With a block given, calls the block with each successive element of self
; stops if the block returns false
or nil
; returns a new Array
omitting those elements for which the block returned a truthy value:
a = [0, 1, 2, 3, 4, 5] a.drop_while {|element| element < 3 } # => [3, 4, 5]
With no block given, returns a new Enumerator:
[0, 1].drop_while # => # => #<Enumerator: [0, 1]:drop_while>
Returns the singleton class of obj. This method creates a new singleton class if obj does not have one.
If obj is nil
, true
, or false
, it returns NilClass
, TrueClass
, or FalseClass
, respectively. If obj is an Integer
, a Float
or a Symbol
, it raises a TypeError
.
Object.new.singleton_class #=> #<Class:#<Object:0xb7ce1e24>> String.singleton_class #=> #<Class:String> nil.singleton_class #=> NilClass
Returns an array of the names of singleton methods for obj. If the optional all parameter is true, the list will include methods in modules included in obj. Only public and protected singleton methods are returned.
module Other def three() end end class Single def Single.four() end end a = Single.new def a.one() end class << a include Other def two() end end Single.singleton_methods #=> [:four] a.singleton_methods(false) #=> [:two, :one] a.singleton_methods #=> [:two, :one, :three]
Returns an array of instance variable names for the receiver. Note that simply defining an accessor does not create the corresponding instance variable.
class Fred attr_accessor :a1 def initialize @iv = 3 end end Fred.new.instance_variables #=> [:@iv]
Similar to method, searches singleton method only.
class Demo def initialize(n) @iv = n end def hello() "Hello, @iv = #{@iv}" end end k = Demo.new(99) def k.hi "Hi, @iv = #{@iv}" end m = k.singleton_method(:hi) m.call #=> "Hi, @iv = 99" m = k.singleton_method(:hello) #=> NameError
Invokes the method identified by symbol, passing it any arguments specified. Unlike send, public_send
calls public methods only. When the method is identified by a string, the string is converted to a symbol.
1.public_send(:puts, "hello") # causes NoMethodError
Returns true
if obj responds to the given method. Private and protected methods are included in the search only if the optional second parameter evaluates to true
.
If the method is not implemented, as Process.fork
on Windows, File.lchmod
on GNU/Linux, etc., false is returned.
If the method is not defined, respond_to_missing?
method is called and the result is returned.
When the method name parameter is given as a string, the string is converted to a symbol.
Returns a hash, that will be turned into a JSON
object and represent this object.
Returns true if str
starts with one of the prefixes
given. Each of the prefixes
should be a String
or a Regexp
.
"hello".start_with?("hell") #=> true "hello".start_with?(/H/i) #=> true # returns true if one of the prefixes matches. "hello".start_with?("heaven", "hell") #=> true "hello".start_with?("heaven", "paradise") #=> false
Passes each character in str to the given block, or returns an enumerator if no block is given.
"hello".each_char {|c| print c, ' ' }
produces:
h e l l o
Returns true for a string which has only ASCII characters.
"abc".force_encoding("UTF-8").ascii_only? #=> true "abc\u{6666}".force_encoding("UTF-8").ascii_only? #=> false
Returns the path parameter passed to dir’s constructor.
d = Dir.new("..") d.path #=> ".."
Converts a pathname to an absolute pathname. Relative paths are referenced from the current working directory of the process unless dir_string is given, in which case it will be used as the starting point. If the given pathname starts with a “~
” it is NOT expanded, it is treated as a normal directory name.
File.absolute_path("~oracle/bin") #=> "<relative_path>/~oracle/bin"
Returns true
if file_name
is an absolute path, and false
otherwise.
File.absolute_path?("c:/foo") #=> false (on Linux), true (on Windows)