Add a certificate to trusted certificate list.
@param [Object] possibility a single possibility @param [Array] requirements an array of requirements @return [Boolean] whether the possibility satisfies all of the
given requirements
@param [String] requirement_name the spec name to search for @return [Object] the locked spec named ‘requirement_name`, if one
is found on {#base}
Checks a proposed requirement with any existing locked requirement before generating an array of possibilities for it. @param [Object] requirement the proposed requirement @param [Object] activated @return [Array] possibilities
Return the class refined by the receiver.
Returns a copy of self
with leading substring prefix
removed:
'hello'.delete_prefix('hel') # => "lo" 'hello'.delete_prefix('llo') # => "hello" 'тест'.delete_prefix('те') # => "ст" 'こんにちは'.delete_prefix('こん') # => "にちは"
Related: String#delete_prefix!
, String#delete_suffix
.
Like String#delete_prefix
, except that self
is modified in place. Returns self
if the prefix is removed, nil
otherwise.
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
.
Returns the Fiber
scheduler, that was last set for the current thread with Fiber.set_scheduler
if and only if the current fiber is non-blocking.
If file_name is readable by others, returns an integer representing the file permission bits of file_name. Returns nil
otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2)
.
file_name can be an IO
object.
File.world_readable?("/etc/passwd") #=> 420 m = File.world_readable?("/etc/passwd") sprintf("%o", m) #=> "644"
Returns true
if the named file is writable by the real user and group id of this process. See access(3).
Note that some OS-level security features may cause this to return true even though the file is not writable by the real user/group.
Returns true
if the named file is executable by the real user and group id of this process. See access(3).
Windows does not support execute permissions separately from read permissions. On Windows, a file is only considered executable if it ends in .bat, .cmd, .com, or .exe.
Note that some OS-level security features may cause this to return true even though the file is not executable by the real user/group.
When this module is included in another, Ruby calls append_features
in this module, passing it the receiving module in mod. Ruby’s default implementation is to add the constants, methods, and module variables of this module to mod if this module has not already been added to mod or one of its ancestors. See also Module#include
.
Returns an array of all modules used in the current scope. The ordering of modules in the resulting array is not defined.
module A refine Object do end end module B refine Object do end end using A using B p Module.used_modules
produces:
[B, A]
Returns the list of modules included or prepended in mod or one of mod’s ancestors.
module Sub end module Mixin prepend Sub end module Outer include Mixin end Mixin.included_modules #=> [Sub] Outer.included_modules #=> [Sub, Mixin]
Creates instance variables and corresponding methods that return the value of each instance variable. Equivalent to calling “attr
:name” on each name in turn. String
arguments are converted to symbols. Returns an array of defined method names as symbols.
Evaluates the given block in the context of the class/module. The method defined in the block will belong to the receiver. Any arguments passed to the method will be passed to the block. This can be used if the block needs to access instance variables.
class Thing end Thing.class_exec{ def hello() "Hello there!" end } puts Thing.new.hello()
produces:
Hello there!
Evaluates the string or block in the context of mod, except that when a block is given, constant/class variable lookup is not affected. This can be used to add methods to a class. module_eval
returns the result of evaluating its argument. The optional filename and lineno parameters set the text for error messages.
class Thing end a = %q{def hello() "Hello there!" end} Thing.module_eval(a) puts Thing.new.hello() Thing.module_eval("invalid code", "dummy", 123)
produces:
Hello there! dummy:123:in `module_eval': undefined local variable or method `code' for Thing:Class
Execute the provided block, but preserve the precision limit
BigDecimal.limit(100) puts BigDecimal.limit BigDecimal.save_limit do BigDecimal.limit(200) puts BigDecimal.limit end puts BigDecimal.limit