milaz / pipes-core Goto Github PK

This library offers an abstraction similar in scope to iteratees/enumerators/enumeratees, but with different characteristics and naming conventions.

Difference with traditional iteratees:

• Simpler semantics: There is only one data type (Pipe), two primitives (await and yield), and only one way to compose Pipes (>+>). In fact, (>+>) is just convenient syntax for the composition operator in Category. Most pipes can be implemented just using the Monad instance and composition.

• Different naming conventions: Enumeratees are called Pipes, Enumerators are Producers, and Iteratees are Consumers. Producers and Consumers are just type synonyms for Pipes with either the input or output end closed.

• Pipes form a Category: that means that composition is associative, and that there is an identity Pipe.

• "Vertical" concatenation works on every Pipe: (>>), concatenates Pipes. Since everything is a Pipe, you can use it to concatenate Producers, Consumers, and even intermediate Pipe stages. Vertical concatenation can be combined with composition to create elaborate combinators, without the need of executing pipes in "passes" or resuming partially executed pipes.

This library is based on the pipes package by Gabriel Gonzales.