@return [String] the name of the source of explicit dependencies, i.e.
those passed to {Resolver#resolve} directly.
@return [String] the name of the source of ‘locked’ dependencies, i.e.
those passed to {Resolver#resolve} directly as the `base`
Load extra data embed into binary format String object.
Returns an array containing the elements in self
corresponding to the given selector
(s).
The selectors may be either integer indices or ranges.
See also Array#select
.
a = %w{ a b c d e f } a.values_at(1, 3, 5) # => ["b", "d", "f"] a.values_at(1, 3, 5, 7) # => ["b", "d", "f", nil] a.values_at(-1, -2, -2, -7) # => ["f", "e", "e", nil] a.values_at(4..6, 3...6) # => ["e", "f", nil, "d", "e", "f"]
Deletes the element at the specified index
, returning that element, or nil
if the index
is out of range.
See also Array#slice!
a = ["ant", "bat", "cat", "dog"] a.delete_at(2) #=> "cat" a #=> ["ant", "bat", "dog"] a.delete_at(99) #=> nil
Returns the number of bits of the value of int.
“the number of bits” means that the bit position of the highest bit which is different to the sign bit. (The bit position of the bit 2**n is n+1.) If there is no such bit (zero or minus one), zero is returned.
I.e. This method returns ceil(log2(int < 0 ? -int : int+1)).
(-2**10000-1).bit_length #=> 10001 (-2**10000).bit_length #=> 10000 (-2**10000+1).bit_length #=> 10000 (-2**1000-1).bit_length #=> 1001 (-2**1000).bit_length #=> 1000 (-2**1000+1).bit_length #=> 1000 (2**1000-1).bit_length #=> 1000 (2**1000).bit_length #=> 1001 (2**1000+1).bit_length #=> 1001 (2**10000-1).bit_length #=> 10000 (2**10000).bit_length #=> 10001 (2**10000+1).bit_length #=> 10001
This method can be used to detect overflow in Array#pack
as follows.
if n.bit_length < 32 [n].pack("l") # no overflow else raise "overflow" end
Returns true if str
starts with one of the prefixes
given.
"hello".start_with?("hell") #=> true # returns true if one of the prefixes matches. "hello".start_with?("heaven", "hell") #=> true "hello".start_with?("heaven", "paradise") #=> false
Returns true if str
ends with one of the suffixes
given.
"hello".end_with?("ello") #=> true # returns true if one of the +suffixes+ matches. "hello".end_with?("heaven", "ello") #=> true "hello".end_with?("heaven", "paradise") #=> false
Returns the next representable floating-point number.
Float::MAX.next_float and Float::INFINITY.next_float is Float::INFINITY
.
Float::NAN.next_float is Float::NAN
.
For example:
p 0.01.next_float #=> 0.010000000000000002 p 1.0.next_float #=> 1.0000000000000002 p 100.0.next_float #=> 100.00000000000001 p 0.01.next_float - 0.01 #=> 1.734723475976807e-18 p 1.0.next_float - 1.0 #=> 2.220446049250313e-16 p 100.0.next_float - 100.0 #=> 1.4210854715202004e-14 f = 0.01; 20.times { printf "%-20a %s\n", f, f.to_s; f = f.next_float } #=> 0x1.47ae147ae147bp-7 0.01 # 0x1.47ae147ae147cp-7 0.010000000000000002 # 0x1.47ae147ae147dp-7 0.010000000000000004 # 0x1.47ae147ae147ep-7 0.010000000000000005 # 0x1.47ae147ae147fp-7 0.010000000000000007 # 0x1.47ae147ae148p-7 0.010000000000000009 # 0x1.47ae147ae1481p-7 0.01000000000000001 # 0x1.47ae147ae1482p-7 0.010000000000000012 # 0x1.47ae147ae1483p-7 0.010000000000000014 # 0x1.47ae147ae1484p-7 0.010000000000000016 # 0x1.47ae147ae1485p-7 0.010000000000000018 # 0x1.47ae147ae1486p-7 0.01000000000000002 # 0x1.47ae147ae1487p-7 0.010000000000000021 # 0x1.47ae147ae1488p-7 0.010000000000000023 # 0x1.47ae147ae1489p-7 0.010000000000000024 # 0x1.47ae147ae148ap-7 0.010000000000000026 # 0x1.47ae147ae148bp-7 0.010000000000000028 # 0x1.47ae147ae148cp-7 0.01000000000000003 # 0x1.47ae147ae148dp-7 0.010000000000000031 # 0x1.47ae147ae148ep-7 0.010000000000000033 f = 0.0 100.times { f += 0.1 } p f #=> 9.99999999999998 # should be 10.0 in the ideal world. p 10-f #=> 1.9539925233402755e-14 # the floating-point error. p(10.0.next_float-10) #=> 1.7763568394002505e-15 # 1 ulp (units in the last place). p((10-f)/(10.0.next_float-10)) #=> 11.0 # the error is 11 ulp. p((10-f)/(10*Float::EPSILON)) #=> 8.8 # approximation of the above. p "%a" % f #=> "0x1.3fffffffffff5p+3" # the last hex digit is 5. 16 - 5 = 11 ulp.
Returns the previous representable floating-point number.
(-Float::MAX).prev_float and (-Float::INFINITY).prev_float is -Float::INFINITY.
Float::NAN.prev_float is Float::NAN
.
For example:
p 0.01.prev_float #=> 0.009999999999999998 p 1.0.prev_float #=> 0.9999999999999999 p 100.0.prev_float #=> 99.99999999999999 p 0.01 - 0.01.prev_float #=> 1.734723475976807e-18 p 1.0 - 1.0.prev_float #=> 1.1102230246251565e-16 p 100.0 - 100.0.prev_float #=> 1.4210854715202004e-14 f = 0.01; 20.times { printf "%-20a %s\n", f, f.to_s; f = f.prev_float } #=> 0x1.47ae147ae147bp-7 0.01 # 0x1.47ae147ae147ap-7 0.009999999999999998 # 0x1.47ae147ae1479p-7 0.009999999999999997 # 0x1.47ae147ae1478p-7 0.009999999999999995 # 0x1.47ae147ae1477p-7 0.009999999999999993 # 0x1.47ae147ae1476p-7 0.009999999999999992 # 0x1.47ae147ae1475p-7 0.00999999999999999 # 0x1.47ae147ae1474p-7 0.009999999999999988 # 0x1.47ae147ae1473p-7 0.009999999999999986 # 0x1.47ae147ae1472p-7 0.009999999999999985 # 0x1.47ae147ae1471p-7 0.009999999999999983 # 0x1.47ae147ae147p-7 0.009999999999999981 # 0x1.47ae147ae146fp-7 0.00999999999999998 # 0x1.47ae147ae146ep-7 0.009999999999999978 # 0x1.47ae147ae146dp-7 0.009999999999999976 # 0x1.47ae147ae146cp-7 0.009999999999999974 # 0x1.47ae147ae146bp-7 0.009999999999999972 # 0x1.47ae147ae146ap-7 0.00999999999999997 # 0x1.47ae147ae1469p-7 0.009999999999999969 # 0x1.47ae147ae1468p-7 0.009999999999999967
Returns default external encoding.
The default external encoding is used by default for strings created from the following locations:
File
data read from disk
While strings created from these locations will have this encoding, the encoding may not be valid. Be sure to check String#valid_encoding?
.
File
data written to disk will be transcoded to the default external encoding when written.
The default external encoding is initialized by the locale or -E option.
Sets default external encoding. You should not set Encoding::default_external
in ruby code as strings created before changing the value may have a different encoding from strings created after the value was changed., instead you should use ruby -E
to invoke ruby with the correct default_external.
See Encoding::default_external
for information on how the default external encoding is used.
Returns default internal encoding. Strings will be transcoded to the default internal encoding in the following places if the default internal encoding is not nil:
File
data read from disk
Strings returned from Readline
Strings returned from SDBM
Values from ENV
Values in ARGV including $PROGRAM_NAME
Additionally String#encode
and String#encode!
use the default internal encoding if no encoding is given.
The locale encoding (__ENCODING__), not default_internal
, is used as the encoding of created strings.
Encoding::default_internal
is initialized by the source file’s internal_encoding or -E option.
Sets default internal encoding or removes default internal encoding when passed nil. You should not set Encoding::default_internal
in ruby code as strings created before changing the value may have a different encoding from strings created after the change. Instead you should use ruby -E
to invoke ruby with the correct default_internal.
See Encoding::default_internal
for information on how the default internal encoding is used.
Iterates the given block for each element with an index, which starts from offset
. If no block is given, returns a new Enumerator
that includes the index, starting from offset
offset
the starting index to use
Iterates the given block for each element with an arbitrary object, obj
, and returns obj
If no block is given, returns a new Enumerator
.
to_three = Enumerator.new do |y| 3.times do |x| y << x end end to_three_with_string = to_three.with_object("foo") to_three_with_string.each do |x,string| puts "#{string}: #{x}" end # => foo:0 # => foo:1 # => foo:2
Returns any backtrace associated with the exception. This method is similar to Exception#backtrace
, but the backtrace is an array of
Thread::Backtrace::Location.
Now, this method is not affected by Exception#set_backtrace()
.
Deserializes JSON
string by constructing new Exception
object with message m
and backtrace b
serialized with to_json