Simple deprecation method that deprecates name
by wrapping it up in a dummy method. It warns on each call to the dummy method telling the user of repl
(unless repl
is :none) and the year/month that it is planned to go away.
Check if gem name
version version
is installed.
A Zlib::Inflate#inflate
wrapper
Dispatch enter and leave events for ConstantOperatorWriteNode
nodes and continue walking the tree.
Dispatch enter and leave events for ConstantPathWriteNode
nodes and continue walking the tree.
Dispatch enter and leave events for InstanceVariableTargetNode
nodes and continue walking the tree.
Returns a new Array whose elements are the elements of self
at the given Integer
or Range
indexes
.
For each positive index
, returns the element at offset index
:
a = [:foo, 'bar', 2] a.values_at(0, 2) # => [:foo, 2] a.values_at(0..1) # => [:foo, "bar"]
The given indexes
may be in any order, and may repeat:
a = [:foo, 'bar', 2] a.values_at(2, 0, 1, 0, 2) # => [2, :foo, "bar", :foo, 2] a.values_at(1, 0..2) # => ["bar", :foo, "bar", 2]
Assigns nil
for an index
that is too large:
a = [:foo, 'bar', 2] a.values_at(0, 3, 1, 3) # => [:foo, nil, "bar", nil]
Returns a new empty Array if no arguments given.
For each negative index
, counts backward from the end of the array:
a = [:foo, 'bar', 2] a.values_at(-1, -3) # => [2, :foo]
Assigns nil
for an index
that is too small:
a = [:foo, 'bar', 2] a.values_at(0, -5, 1, -6, 2) # => [:foo, nil, "bar", nil, 2]
The given indexes
may have a mixture of signs:
a = [:foo, 'bar', 2] a.values_at(0, -2, 1, -1) # => [:foo, "bar", "bar", 2]
Deletes an element from self
, per the given Integer
index
.
When index
is non-negative, deletes the element at offset index
:
a = [:foo, 'bar', 2] a.delete_at(1) # => "bar" a # => [:foo, 2]
If index is too large, returns nil
.
When index
is negative, counts backward from the end of the array:
a = [:foo, 'bar', 2] a.delete_at(-2) # => "bar" a # => [:foo, 2]
If index
is too small (far from zero), returns nil.
Returns a new Array containing zero or more leading 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 containing those elements for which the block returned a truthy value:
a = [0, 1, 2, 3, 4, 5] a.take_while {|element| element < 3 } # => [0, 1, 2] a.take_while {|element| true } # => [0, 1, 2, 3, 4, 5] a # => [0, 1, 2, 3, 4, 5]
With no block given, returns a new Enumerator:
[0, 1].take_while # => #<Enumerator: [0, 1]:take_while>
Returns whether self
starts with any of the given string_or_regexp
.
Matches patterns against the beginning of self
. For each given string_or_regexp
, the pattern is:
string_or_regexp
itself, if it is a Regexp
.
Regexp.quote(string_or_regexp)
, if string_or_regexp
is a string.
Returns true
if any pattern matches the beginning, false
otherwise:
'hello'.start_with?('hell') # => true 'hello'.start_with?(/H/i) # => true 'hello'.start_with?('heaven', 'hell') # => true 'hello'.start_with?('heaven', 'paradise') # => false 'тест'.start_with?('т') # => true 'こんにちは'.start_with?('こ') # => true
Related: String#end_with?
.
Returns the next-larger representable Float.
These examples show the internally stored values (64-bit hexadecimal) for each Float f
and for the corresponding f.next_float
:
f = 0.0 # 0x0000000000000000 f.next_float # 0x0000000000000001 f = 0.01 # 0x3f847ae147ae147b f.next_float # 0x3f847ae147ae147c
In the remaining examples here, the output is shown in the usual way (result to_s
):
0.01.next_float # => 0.010000000000000002 1.0.next_float # => 1.0000000000000002 100.0.next_float # => 100.00000000000001 f = 0.01 (0..3).each_with_index {|i| printf "%2d %-20a %s\n", i, f, f.to_s; f = f.next_float }
Output:
0 0x1.47ae147ae147bp-7 0.01 1 0x1.47ae147ae147cp-7 0.010000000000000002 2 0x1.47ae147ae147dp-7 0.010000000000000004 3 0x1.47ae147ae147ep-7 0.010000000000000005 f = 0.0; 100.times { f += 0.1 } f # => 9.99999999999998 # should be 10.0 in the ideal world. 10-f # => 1.9539925233402755e-14 # the floating point error. 10.0.next_float-10 # => 1.7763568394002505e-15 # 1 ulp (unit in the last place). (10-f)/(10.0.next_float-10) # => 11.0 # the error is 11 ulp. (10-f)/(10*Float::EPSILON) # => 8.8 # approximation of the above. "%a" % 10 # => "0x1.4p+3" "%a" % f # => "0x1.3fffffffffff5p+3" # the last hex digit is 5. 16 - 5 = 11 ulp.
Related: Float#prev_float
Returns the next-smaller representable Float.
These examples show the internally stored values (64-bit hexadecimal) for each Float f
and for the corresponding f.pev_float
:
f = 5e-324 # 0x0000000000000001 f.prev_float # 0x0000000000000000 f = 0.01 # 0x3f847ae147ae147b f.prev_float # 0x3f847ae147ae147a
In the remaining examples here, the output is shown in the usual way (result to_s
):
0.01.prev_float # => 0.009999999999999998 1.0.prev_float # => 0.9999999999999999 100.0.prev_float # => 99.99999999999999 f = 0.01 (0..3).each_with_index {|i| printf "%2d %-20a %s\n", i, f, f.to_s; f = f.prev_float }
Output:
0 0x1.47ae147ae147bp-7 0.01 1 0x1.47ae147ae147ap-7 0.009999999999999998 2 0x1.47ae147ae1479p-7 0.009999999999999997 3 0x1.47ae147ae1478p-7 0.009999999999999995
Related: Float#next_float
.
Like backtrace
, but returns each line of the execution stack as a Thread::Backtrace::Location
. Accepts the same arguments as backtrace
.
f = Fiber.new { Fiber.yield } f.resume loc = f.backtrace_locations.first loc.label #=> "yield" loc.path #=> "test.rb" loc.lineno #=> 1
Returns the dirpath
string that was used to create self
(or nil
if created by method Dir.for_fd
):
Dir.new('example').path # => "example"
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. The given pathname may start with a “~
”, which expands to the process owner’s home directory (the environment variable HOME
must be set correctly). “~
user” expands to the named user’s home directory.
File.expand_path("~oracle/bin") #=> "/home/oracle/bin"
A simple example of using dir_string
is as follows.
File.expand_path("ruby", "/usr/bin") #=> "/usr/bin/ruby"
A more complex example which also resolves parent directory is as follows. Suppose we are in bin/mygem and want the absolute path of lib/mygem.rb.
File.expand_path("../../lib/mygem.rb", __FILE__) #=> ".../path/to/project/lib/mygem.rb"
So first it resolves the parent of __FILE__, that is bin/, then go to the parent, the root of the project and appends lib/mygem.rb
.
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"