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Welcome to the Wiki! Here's what we got:

• What It Is
• Stream From Array
• Generate an Infinite Stream
• Methods

What It Is

Inspired by Java 8's Stream API, ruby-stream-api aims to provide a wide range of useful Streams for Ruby.

A Stream is a wrapper over a collection of elements offering a number of useful operations to modify and/or get information about the collection. The operations are chainable and can be categorized as follows:

• Source operations -- these are the operations which are generating the Stream.
• Intermediate operations (skip, filter, map etc) -- operations which are altering the Stream and still leave it open for further modifications.
• Terminal operations (count, collect etc) -- operations which are executed after all the modifications have been done and are returning a finite result.

Stream From Array

stream = Stream::FromArray.new([1, 2, 3, 4])
# or, if you want to hide the class
stream = Stream.from_array([1, 2, 3, 4])

Generate an Infinite Stream

stream = Stream.generate(150) { &seed }

The generate method takes a limit (max number of elements) and a &seed Block function which returns a new element at each seed.call. A limit is necessary as, without it, this Stream would be infinite. If no limit is specified, the default is 100 elements.

This mechanism is useful, for instance, when you have to consume an incomming stream of objects from some IO objects.

Methods

1. Intermediate and chainable:

   • filter(&condition) - filter out elements which do not satisfy the condition
   • map(&function) - map the stream's element using the given function
   • distinct - remove all duplicates from the stream
   • skip(n) - skip the first n elements of the stream

2. Terminal:

   • collect - collect the stream's elements into an array
   • count - return the number of elements in the stream
   • all_match(&test) - return true if all elements pass the test (true if the stream is empty)
   • any_match(&test) - returns true if any element passes the test (false if the stream is empty)