ruby/kernel.rb

313 строки
8.8 KiB
Ruby

module Kernel
#
# call-seq:
# obj.class -> class
#
# Returns the class of <i>obj</i>. This method must always be called
# with an explicit receiver, as #class is also a reserved word in
# Ruby.
#
# 1.class #=> Integer
# self.class #=> Object
#--
# Equivalent to \c Object\#class in Ruby.
#
# Returns the class of \c obj, skipping singleton classes or module inclusions.
#++
#
def class
Primitive.attr! :leaf
Primitive.cexpr! 'rb_obj_class(self)'
end
#
# call-seq:
# obj.clone(freeze: nil) -> an_object
#
# Produces a shallow copy of <i>obj</i>---the instance variables of
# <i>obj</i> are copied, but not the objects they reference.
# #clone copies the frozen value state of <i>obj</i>, unless the
# +:freeze+ keyword argument is given with a false or true value.
# See also the discussion under Object#dup.
#
# class Klass
# attr_accessor :str
# end
# s1 = Klass.new #=> #<Klass:0x401b3a38>
# s1.str = "Hello" #=> "Hello"
# s2 = s1.clone #=> #<Klass:0x401b3998 @str="Hello">
# s2.str[1,4] = "i" #=> "i"
# s1.inspect #=> "#<Klass:0x401b3a38 @str=\"Hi\">"
# s2.inspect #=> "#<Klass:0x401b3998 @str=\"Hi\">"
#
# This method may have class-specific behavior. If so, that
# behavior will be documented under the #+initialize_copy+ method of
# the class.
#
def clone(freeze: nil)
Primitive.rb_obj_clone2(freeze)
end
#
# call-seq:
# obj.frozen? -> true or false
#
# Returns the freeze status of <i>obj</i>.
#
# a = [ "a", "b", "c" ]
# a.freeze #=> ["a", "b", "c"]
# a.frozen? #=> true
#--
# Determines if the object is frozen. Equivalent to \c Object\#frozen? in Ruby.
# \param[in] obj the object to be determines
# \retval Qtrue if frozen
# \retval Qfalse if not frozen
#++
#
def frozen?
Primitive.attr! :leaf
Primitive.cexpr! 'rb_obj_frozen_p(self)'
end
#
# call-seq:
# obj.tap {|x| block } -> obj
#
# Yields self to the block, and then returns self.
# The primary purpose of this method is to "tap into" a method chain,
# in order to perform operations on intermediate results within the chain.
#
# (1..10) .tap {|x| puts "original: #{x}" }
# .to_a .tap {|x| puts "array: #{x}" }
# .select {|x| x.even? } .tap {|x| puts "evens: #{x}" }
# .map {|x| x*x } .tap {|x| puts "squares: #{x}" }
#
#--
# \private
#++
#
def tap
yield(self)
self
end
#
# call-seq:
# obj.then {|x| block } -> an_object
#
# Yields self to the block and returns the result of the block.
#
# 3.next.then {|x| x**x }.to_s #=> "256"
#
# Good usage for +then+ is value piping in method chains:
#
# require 'open-uri'
# require 'json'
#
# construct_url(arguments).
# then {|url| URI(url).read }.
# then {|response| JSON.parse(response) }
#
# When called without block, the method returns +Enumerator+,
# which can be used, for example, for conditional
# circuit-breaking:
#
# # meets condition, no-op
# 1.then.detect(&:odd?) # => 1
# # does not meet condition, drop value
# 2.then.detect(&:odd?) # => nil
#
def then
unless block_given?
return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, rb_obj_size)'
end
yield(self)
end
#
# call-seq:
# obj.yield_self {|x| block } -> an_object
#
# Yields self to the block and returns the result of the block.
#
# "my string".yield_self {|s| s.upcase } #=> "MY STRING"
#
# Good usage for +then+ is value piping in method chains:
#
# require 'open-uri'
# require 'json'
#
# construct_url(arguments).
# then {|url| URI(url).read }.
# then {|response| JSON.parse(response) }
#
def yield_self
unless block_given?
return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, rb_obj_size)'
end
yield(self)
end
module_function
# call-seq:
# loop { block }
# loop -> an_enumerator
#
# Repeatedly executes the block.
#
# If no block is given, an enumerator is returned instead.
#
# loop do
# print "Input: "
# line = gets
# break if !line or line =~ /^q/i
# # ...
# end
#
# StopIteration raised in the block breaks the loop. In this case,
# loop returns the "result" value stored in the exception.
#
# enum = Enumerator.new { |y|
# y << "one"
# y << "two"
# :ok
# }
#
# result = loop {
# puts enum.next
# } #=> :ok
def loop
unless block_given?
return enum_for(:loop) { Float::INFINITY }
end
begin
while true
yield
end
rescue StopIteration => e
e.result
end
end
#
# call-seq:
# Float(arg, exception: true) -> float or nil
#
# Returns <i>arg</i> converted to a float. Numeric types are
# converted directly, and with exception to String and
# <code>nil</code> the rest are converted using
# <i>arg</i><code>.to_f</code>. Converting a String with invalid
# characters will result in a ArgumentError. Converting
# <code>nil</code> generates a TypeError. Exceptions can be
# suppressed by passing <code>exception: false</code>.
#
# Float(1) #=> 1.0
# Float("123.456") #=> 123.456
# Float("123.0_badstring") #=> ArgumentError: invalid value for Float(): "123.0_badstring"
# Float(nil) #=> TypeError: can't convert nil into Float
# Float("123.0_badstring", exception: false) #=> nil
#
def Float(arg, exception: true)
if Primitive.mandatory_only?
Primitive.rb_f_float1(arg)
else
Primitive.rb_f_float(arg, exception)
end
end
# call-seq:
# Integer(object, base = 0, exception: true) -> integer or nil
#
# Returns an integer converted from +object+.
#
# Tries to convert +object+ to an integer
# using +to_int+ first and +to_i+ second;
# see below for exceptions.
#
# With a non-zero +base+, +object+ must be a string or convertible
# to a string.
#
# ==== numeric objects
#
# With integer argument +object+ given, returns +object+:
#
# Integer(1) # => 1
# Integer(-1) # => -1
#
# With floating-point argument +object+ given,
# returns +object+ truncated to an integer:
#
# Integer(1.9) # => 1 # Rounds toward zero.
# Integer(-1.9) # => -1 # Rounds toward zero.
#
# ==== string objects
#
# With string argument +object+ and zero +base+ given,
# returns +object+ converted to an integer in base 10:
#
# Integer('100') # => 100
# Integer('-100') # => -100
#
# With +base+ zero, string +object+ may contain leading characters
# to specify the actual base (radix indicator):
#
# Integer('0100') # => 64 # Leading '0' specifies base 8.
# Integer('0b100') # => 4 # Leading '0b', specifies base 2.
# Integer('0x100') # => 256 # Leading '0x' specifies base 16.
#
# With a positive +base+ (in range 2..36) given, returns +object+
# converted to an integer in the given base:
#
# Integer('100', 2) # => 4
# Integer('100', 8) # => 64
# Integer('-100', 16) # => -256
#
# With a negative +base+ (in range -36..-2) given, returns +object+
# converted to an integer in the radix indicator if exists or
# +-base+:
#
# Integer('0x100', -2) # => 256
# Integer('100', -2) # => 4
# Integer('0b100', -8) # => 4
# Integer('100', -8) # => 64
# Integer('0o100', -10) # => 64
# Integer('100', -10) # => 100
#
# +base+ -1 is equal the -10 case.
#
# When converting strings, surrounding whitespace and embedded underscores
# are allowed and ignored:
#
# Integer(' 100 ') # => 100
# Integer('-1_0_0', 16) # => -256
#
# ==== other classes
#
# Examples with +object+ of various other classes:
#
# Integer(Rational(9, 10)) # => 0 # Rounds toward zero.
# Integer(Complex(2, 0)) # => 2 # Imaginary part must be zero.
# Integer(Time.now) # => 1650974042
#
# ==== keywords
#
# With optional keyword argument +exception+ given as +true+ (the default):
#
# - Raises TypeError if +object+ does not respond to +to_int+ or +to_i+.
# - Raises TypeError if +object+ is +nil+.
# - Raise ArgumentError if +object+ is an invalid string.
#
# With +exception+ given as +false+, an exception of any kind is suppressed
# and +nil+ is returned.
def Integer(arg, base = 0, exception: true)
if Primitive.mandatory_only?
Primitive.rb_f_integer1(arg)
else
Primitive.rb_f_integer(arg, base, exception);
end
end
end