Returns the inner product of this vector with the other.
Vector[4,7].inner_product Vector[10,1] => 47
Creates an OptionParser::Switch
from the parameters. The parsed argument value is passed to the given block, where it can be processed.
See at the beginning of OptionParser
for some full examples.
opts
can include the following elements:
One of the following:
:NONE, :REQUIRED, :OPTIONAL
Acceptable option argument format, must be pre-defined with OptionParser.accept
or OptionParser#accept
, or Regexp
. This can appear once or assigned as String if not present, otherwise causes an ArgumentError
. Examples:
Float, Time, Array
Hash
or Array.
[:text, :binary, :auto] %w[iso-2022-jp shift_jis euc-jp utf8 binary] { "jis" => "iso-2022-jp", "sjis" => "shift_jis" }
Specifies a long style switch which takes a mandatory, optional or no argument. It’s a string of the following form:
"--switch=MANDATORY" or "--switch MANDATORY" "--switch[=OPTIONAL]" "--switch"
Specifies short style switch which takes a mandatory, optional or no argument. It’s a string of the following form:
"-xMANDATORY" "-x[OPTIONAL]" "-x"
There is also a special form which matches character range (not full set of regular expression):
"-[a-z]MANDATORY" "-[a-z][OPTIONAL]" "-[a-z]"
Instead of specifying mandatory or optional arguments directly in the switch parameter, this separate parameter can be used.
"=MANDATORY" "=[OPTIONAL]"
Description string for the option.
"Run verbosely"
Handler for the parsed argument value. Either give a block or pass a Proc
or Method
as an argument.
Creates an OptionParser::Switch
from the parameters. The parsed argument value is passed to the given block, where it can be processed.
See at the beginning of OptionParser
for some full examples.
opts
can include the following elements:
One of the following:
:NONE, :REQUIRED, :OPTIONAL
Acceptable option argument format, must be pre-defined with OptionParser.accept
or OptionParser#accept
, or Regexp
. This can appear once or assigned as String if not present, otherwise causes an ArgumentError
. Examples:
Float, Time, Array
Hash
or Array.
[:text, :binary, :auto] %w[iso-2022-jp shift_jis euc-jp utf8 binary] { "jis" => "iso-2022-jp", "sjis" => "shift_jis" }
Specifies a long style switch which takes a mandatory, optional or no argument. It’s a string of the following form:
"--switch=MANDATORY" or "--switch MANDATORY" "--switch[=OPTIONAL]" "--switch"
Specifies short style switch which takes a mandatory, optional or no argument. It’s a string of the following form:
"-xMANDATORY" "-x[OPTIONAL]" "-x"
There is also a special form which matches character range (not full set of regular expression):
"-[a-z]MANDATORY" "-[a-z][OPTIONAL]" "-[a-z]"
Instead of specifying mandatory or optional arguments directly in the switch parameter, this separate parameter can be used.
"=MANDATORY" "=[OPTIONAL]"
Description string for the option.
"Run verbosely"
Handler for the parsed argument value. Either give a block or pass a Proc
or Method
as an argument.
Returns the portion of the original string before the current match. Equivalent to the special variable $`
.
m = /(.)(.)(\d+)(\d)/.match("THX1138.") m.pre_match #=> "T"
Returns the portion of the original string after the current match. Equivalent to the special variable $'
.
m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie") m.post_match #=> ": The Movie"
Raises PStore::Error
if the calling code is not in a PStore#transaction
.
As int
is already an Integer
, all these methods simply return the receiver.
Dup internal hash.
Clone internal hash.
Convenience method for Shell::CommandProcessor.alias_command
. Defines an instance method which will execute a command under an alternative name.
Shell.def_system_command('date') Shell.alias_command('date_in_utc', 'date', '-u') Shell.new.date_in_utc # => Sat Jan 25 16:59:57 UTC 2014
Convenience method for Shell::CommandProcessor.unalias_command
Specifies the threads that this object will wait for, but does not actually wait.
Specifies the threads that this object will wait for, but does not actually wait.
Changes asynchronous interrupt timing.
interrupt means asynchronous event and corresponding procedure by Thread#raise
, Thread#kill
, signal trap (not supported yet) and main thread termination (if main thread terminates, then all other thread will be killed).
The given hash
has pairs like ExceptionClass => :TimingSymbol
. Where the ExceptionClass is the interrupt handled by the given block. The TimingSymbol can be one of the following symbols:
:immediate
Invoke interrupts immediately.
:on_blocking
Invoke interrupts while BlockingOperation.
:never
Never invoke all interrupts.
BlockingOperation means that the operation will block the calling thread, such as read and write. On CRuby implementation, BlockingOperation is any operation executed without GVL.
Masked asynchronous interrupts are delayed until they are enabled. This method is similar to sigprocmask(3).
Asynchronous interrupts are difficult to use.
If you need to communicate between threads, please consider to use another way such as Queue
.
Or use them with deep understanding about this method.
In this example, we can guard from Thread#raise
exceptions.
Using the :never
TimingSymbol the RuntimeError
exception will always be ignored in the first block of the main thread. In the second ::handle_interrupt
block we can purposefully handle RuntimeError
exceptions.
th = Thread.new do Thread.handle_interrupt(RuntimeError => :never) { begin # You can write resource allocation code safely. Thread.handle_interrupt(RuntimeError => :immediate) { # ... } ensure # You can write resource deallocation code safely. end } end Thread.pass # ... th.raise "stop"
While we are ignoring the RuntimeError
exception, it’s safe to write our resource allocation code. Then, the ensure block is where we can safely deallocate your resources.
Timeout::Error
In the next example, we will guard from the Timeout::Error
exception. This will help prevent from leaking resources when Timeout::Error
exceptions occur during normal ensure clause. For this example we use the help of the standard library Timeout
, from lib/timeout.rb
require 'timeout' Thread.handle_interrupt(Timeout::Error => :never) { timeout(10){ # Timeout::Error doesn't occur here Thread.handle_interrupt(Timeout::Error => :on_blocking) { # possible to be killed by Timeout::Error # while blocking operation } # Timeout::Error doesn't occur here } }
In the first part of the timeout
block, we can rely on Timeout::Error
being ignored. Then in the Timeout::Error => :on_blocking
block, any operation that will block the calling thread is susceptible to a Timeout::Error
exception being raised.
It’s possible to stack multiple levels of ::handle_interrupt
blocks in order to control more than one ExceptionClass and TimingSymbol at a time.
Thread.handle_interrupt(FooError => :never) { Thread.handle_interrupt(BarError => :never) { # FooError and BarError are prohibited. } }
All exceptions inherited from the ExceptionClass parameter will be considered.
Thread.handle_interrupt(Exception => :never) { # all exceptions inherited from Exception are prohibited. }
Returns the original name of the method.
Returns the original name of the method.
Return class or module of the method being called.
class C; def foo; end; end trace = TracePoint.new(:call) do |tp| p tp.defined_class #=> C end.enable do C.new.foo end
If method is defined by a module, then that module is returned.
module M; def foo; end; end class C; include M; end; trace = TracePoint.new(:call) do |tp| p tp.defined_class #=> M end.enable do C.new.foo end
Note: defined_class
returns singleton class.
6th block parameter of Kernel#set_trace_func
passes original class of attached by singleton class.
This is a difference between Kernel#set_trace_func and TracePoint.
class C; def self.foo; end; end trace = TracePoint.new(:call) do |tp| p tp.defined_class #=> #<Class:C> end.enable do C.foo end
Returns a pretty printed object as a string.
In order to use this method you must first require the PP
module:
require 'pp'
See the PP
module for more information.
Returns an array containing all elements of enum
for which the given block
returns a true value.
If no block is given, an Enumerator
is returned instead.
(1..10).find_all { |i| i % 3 == 0 } #=> [3, 6, 9] [1,2,3,4,5].select { |num| num.even? } #=> [2, 4]
See also Enumerable#reject
.