A String object holds and manipulates an arbitrary sequence of bytes, typically representing characters. String objects may be created using String::new or as literals. Because of aliasing issues, users of strings should be aware of the methods that modify the contents of a String object. Typically, methods with names ending in “!'' modify their receiver, while those without a “!'' return a new St
returns a proxy URI. The proxy URI is obtained from environment variables such as http_proxy, ftp_proxy, no_proxy, etc. If there is no proper proxy, nil is returned. Note that capitalized variables (HTTP_PROXY, FTP_PROXY, NO_PROXY, etc.) are examined too. But http_proxy and HTTP_PROXY is treated specially under CGI environment. It's because HTTP_PROXY may be set by Proxy: header. So HTTP_PROXY is
This class provides a way to synchronize communication between threads. Example: require 'thread' queue = Queue.new producer = Thread.new do 5.times do |i| sleep rand(i) # simulate expense queue << i puts "#{i} produced" end end consumer = Thread.new do 5.times do |i| value = queue.pop sleep rand(i/2) # simulate expense puts "consumed #{value}" end end consumer.join
VALUE rb_mutex_lock(VALUE self) { rb_thread_t *th = GET_THREAD(); rb_mutex_t *mutex; GetMutexPtr(self, mutex); /* When running trap handler */ if (!mutex->allow_trap && th->interrupt_mask & TRAP_INTERRUPT_MASK) { rb_raise(rb_eThreadError, "can't be called from trap context"); } if (rb_mutex_trylock(self) == Qfalse) { if (mutex->th == GET_THREAD()) { rb_raise(rb_eThreadError, "deadlock; recursive l
Threads are the Ruby implementation for a concurrent programming model. Programs that require multiple threads of execution are a perfect candidate for Ruby's Thread class. For example, we can create a new thread separate from the main thread's execution using ::new. thr = Thread.new { puts "Whats the big deal" } Then we are able to pause the execution of the main thread and allow our new thread t
Descendants of class Exception are used to communicate between Kernel#raise and rescue statements in begin ... end blocks. Exception objects carry information about the exception – its type (the exception's class name), an optional descriptive string, and optional traceback information. Exception subclasses may add additional information like NameError#name. Programs may make subclasses of Excepti
A Module is a collection of methods and constants. The methods in a module may be instance methods or module methods. Instance methods appear as methods in a class when the module is included, module methods do not. Conversely, module methods may be called without creating an encapsulating object, while instance methods may not. (See Module#module_function) In the descriptions that follow, the par
A Hash is a dictionary-like collection of unique keys and their values. Also called associative arrays, they are similar to Arrays, but where an Array uses integers as its index, a Hash allows you to use any object type. Hashes enumerate their values in the order that the corresponding keys were inserted. A Hash can be easily created by using its implicit form: grades = { "Jane Doe" => 10, "Jim Do
Holds Integer values that can be represented in a native machine word (minus 1 bit). If any operation on a Fixnum exceeds this range, the value is automatically converted to a Bignum. Fixnum objects have immediate value. This means that when they are assigned or passed as parameters, the actual object is passed, rather than a reference to that object. Assignment does not alias Fixnum objects. Ther
Bignum objects hold integers outside the range of Fixnum. Bignum objects are created automatically when integer calculations would otherwise overflow a Fixnum. When a calculation involving Bignum objects returns a result that will fit in a Fixnum, the result is automatically converted. For the purposes of the bitwise operations and [], a Bignum is treated as if it were an infinite-length bitstring
Float objects represent inexact real numbers using the native architecture's double-precision floating point representation. Floating point has a different arithmetic and is an inexact number. So you should know its esoteric system. see following: docs.sun.com/source/806-3568/ncg_goldberg.html wiki.github.com/rdp/ruby_tutorials_core/ruby-talk-faq#wiki-floats_imprecise en.wikipedia.org/wiki/Floatin
The Math module contains module functions for basic trigonometric and transcendental functions. See class Float for a list of constants that define Ruby's floating point accuracy. Domains and codomains are given only for real (not complex) numbers. Constants E Definition of the mathematical constant E (e) as a Float number. PI Definition of the mathematical constant PI as a Float number.
ARGF is a stream designed for use in scripts that process files given as command-line arguments or passed in via STDIN. The arguments passed to your script are stored in the ARGV Array, one argument per element. ARGF assumes that any arguments that aren't filenames have been removed from ARGV. For example: $ ruby argf.rb --verbose file1 file2 ARGV #=> ["--verbose", "file1", "file2"] option = ARGV.
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