Data.Machine.Source

A Source never reads from its inputs.

A SourceT never reads from its inputs, but may have monadic side-effects.

Generate a Source from any Foldable container.

This can be constructed from a plan with source :: Foldable f => f b -> Source b source = construct (traverse_ yield xs)

Examples:

>>> run $ source [1,2][1,2]

Repeat the same value, over and over.

This can be constructed from a plan with repeated :: o -> Source o repeated = repeatedly . yield

Examples:

>>> run $ taking 5 <~ repeated 1[1,1,1,1,1]

Loop through a Foldable container over and over.

This can be constructed from a plan with cycled :: Foldable f => f b -> Source b cycled = repeatedly (traverse_ yield xs)

Examples:

>>> run $ taking 5 <~ cycled [1,2][1,2,1,2,1]

You can transform a Source with a Process.

Alternately you can view this as capping the Source end of a Process, yielding a new Source.

cap l r = l <~ r

You can transform any MachineT into a SourceT, blocking its input.

This is used by capT, and capWye, and allows an efficient way to plug together machines of different input languages.

iterated f x returns an infinite source of repeated applications of f to x

replicated n x is a source of x emitted n time(s)

Enumerate from a value to a final value, inclusive, via succ

Examples:

>>> run $ enumerateFromTo 1 3[1,2,3]

unfold k seed The function takes the element and returns Nothing if it is done producing values or returns Just (a,r), in which case, a is yielded and r is used as the next element in a recursive call.

Effectful unfold variant.