File-based session storage class.
Implements session storage as a flat file of ‘key=value’ values. This storage type only works directly with String values; the user is responsible for converting other types to Strings when storing and from Strings when retrieving.
Dummy session storage class.
Implements session storage place holder. No actual storage will be done.
PStore-based session storage class.
This builds upon the top-level PStore
class provided by the library file pstore.rb. Session
data is marshalled and stored in a file. File
locking and transaction services are provided.
The Transitive
formatter writes an XML
document that parses to an identical document as the source document. This means that no extra whitespace nodes are inserted, and whitespace within text nodes is preserved. Within these constraints, the document is pretty-printed, with whitespace inserted into the metadata to introduce formatting.
Note that this is only useful if the original XML
is not already formatted. Since this formatter does not alter whitespace nodes, the results of formatting already formatted XML
will be odd.
Used Internally. Wraps a Dependency object to also track which spec contained the Dependency.
A VendorSpecification
represents a gem that has been unpacked into a project and is being loaded through a gem dependencies file through the path:
option.
Delegates
all {Gem::Resolver::Molinillo::ResolutionState} methods to a ‘#state` property.
Indicates a problem with the DNS
request.
IO
wrapper that allows writing a limited amount of data
Provides information about specifcations and dependencies to the resolver, allowing the {Resolver} class to remain generic while still providing power and flexibility.
This module contains the methods that users of Gem::Resolver::Molinillo
must to implement, using knowledge of their own model classes.
Continuation
objects are generated by Kernel#callcc
, after having +require+d continuation. They hold a return address and execution context, allowing a nonlocal return to the end of the callcc
block from anywhere within a program. Continuations are somewhat analogous to a structured version of C’s setjmp/longjmp
(although they contain more state, so you might consider them closer to threads).
For instance:
require "continuation" arr = [ "Freddie", "Herbie", "Ron", "Max", "Ringo" ] callcc{|cc| $cc = cc} puts(message = arr.shift) $cc.call unless message =~ /Max/
produces:
Freddie Herbie Ron Max
Also you can call callcc in other methods:
require "continuation" def g arr = [ "Freddie", "Herbie", "Ron", "Max", "Ringo" ] cc = callcc { |cc| cc } puts arr.shift return cc, arr.size end def f c, size = g c.call(c) if size > 1 end f
This (somewhat contrived) example allows the inner loop to abandon processing early:
require "continuation" callcc {|cont| for i in 0..4 print "\n#{i}: " for j in i*5...(i+1)*5 cont.call() if j == 17 printf "%3d", j end end } puts
produces:
0: 0 1 2 3 4 1: 5 6 7 8 9 2: 10 11 12 13 14 3: 15 16
ConditionVariable
objects augment class Mutex
. Using condition variables, it is possible to suspend while in the middle of a critical section until a resource becomes available.
Example:
mutex = Mutex.new resource = ConditionVariable.new a = Thread.new { mutex.synchronize { # Thread 'a' now needs the resource resource.wait(mutex) # 'a' can now have the resource } } b = Thread.new { mutex.synchronize { # Thread 'b' has finished using the resource resource.signal } }
Raised to stop the iteration, in particular by Enumerator#next
. It is rescued by Kernel#loop
.
loop do puts "Hello" raise StopIteration puts "World" end puts "Done!"
produces:
Hello Done!
An OpenStruct
is a data structure, similar to a Hash
, that allows the definition of arbitrary attributes with their accompanying values. This is accomplished by using Ruby’s metaprogramming to define methods on the class itself.
require "ostruct" person = OpenStruct.new person.name = "John Smith" person.age = 70 person.name # => "John Smith" person.age # => 70 person.address # => nil
An OpenStruct
employs a Hash
internally to store the attributes and values and can even be initialized with one:
australia = OpenStruct.new(:country => "Australia", :capital => "Canberra") # => #<OpenStruct country="Australia", capital="Canberra">
Hash
keys with spaces or characters that could normally not be used for method calls (e.g. ()[]*
) will not be immediately available on the OpenStruct
object as a method for retrieval or assignment, but can still be reached through the Object#send
method.
measurements = OpenStruct.new("length (in inches)" => 24) measurements.send("length (in inches)") # => 24 message = OpenStruct.new(:queued? => true) message.queued? # => true message.send("queued?=", false) message.queued? # => false
Removing the presence of an attribute requires the execution of the delete_field
method as setting the property value to nil
will not remove the attribute.
first_pet = OpenStruct.new(:name => "Rowdy", :owner => "John Smith") second_pet = OpenStruct.new(:name => "Rowdy") first_pet.owner = nil first_pet # => #<OpenStruct name="Rowdy", owner=nil> first_pet == second_pet # => false first_pet.delete_field(:owner) first_pet # => #<OpenStruct name="Rowdy"> first_pet == second_pet # => true
An OpenStruct
utilizes Ruby’s method lookup structure to find and define the necessary methods for properties. This is accomplished through the methods method_missing and define_singleton_method.
This should be a consideration if there is a concern about the performance of the objects that are created, as there is much more overhead in the setting of these properties compared to using a Hash
or a Struct
.
Kanji Converter for Ruby.
A specific resolution from a given {Resolver}
Delegates
all {Gem::Resolver::Molinillo::SpecificationProvider} methods to a ‘#specification_provider` property.