Cont

• Computation type: Computations which can be interrupted and resumed.
• Binding strategy: Binding a function to a monadic value creates a new continuation which uses the function as the continuation of the monadic computation.
• Useful for: Complex control structures, error handling, and creating co-routines.
• Zero and plus: None.
• Example type: Cont r a

The Continuation monad represents computations in continuation-passing style (CPS). In continuation-passing style function result is not returned, but instead is passed to another function, received as a parameter (continuation). Computations are built up from sequences of nested continuations, terminated by a final continuation (often id) which produces the final result. Since continuations are functions which represent the future of a computation, manipulation of the continuation functions can achieve complex manipulations of the future of the computation, such as interrupting a computation in the middle, aborting a portion of a computation, restarting a computation, and interleaving execution of computations. The Continuation monad adapts CPS to the structure of a monad. Before using the Continuation monad, be sure that you have a firm understanding of continuation-passing style and that continuations represent the best solution to your particular design problem. Many algorithms which require continuations in other languages do not require them in Haskell, due to Haskell's lazy semantics. Abuse of the Continuation monad can produce code that is impossible to understand and maintain.

Continuation monad. Cont r a is a CPS ("continuation-passing style") computation that produces an intermediate result of type a within a CPS computation whose final result type is r. The return function simply creates a continuation which passes the value on. The >>= operator adds the bound function into the continuation chain.

Continuation monads. Delimited continuation operators are taken from Kenichi Asai and Oleg Kiselyov's tutorial at CW 2011, "Introduction to programming with shift and reset" (http://okmij.org/ftp/continuations/#tutorial).

The continuation monad, which is non-strict. Cont r a is a CPS ("continuation-passing style") computation that produces an intermediate result of type a within a CPS computation whose final result type is r. The return function simply creates a continuation which passes the value on. The >>= operator adds the bound function into the continuation chain.

• Computation type: Computations which can be interrupted and resumed.
• Binding strategy: Binding a function to a monadic value creates a new continuation which uses the function as the continuation of the monadic computation.
• Useful for: Complex control structures, error handling, and creating co-routines.
• Zero and plus: None.
• Example type: Cont r a

The Continuation monad represents computations in continuation-passing style (CPS). In continuation-passing style function result is not returned, but instead is passed to another function, received as a parameter (continuation). Computations are built up from sequences of nested continuations, terminated by a final continuation (often id) which produces the final result. Since continuations are functions which represent the future of a computation, manipulation of the continuation functions can achieve complex manipulations of the future of the computation, such as interrupting a computation in the middle, aborting a portion of a computation, restarting a computation, and interleaving execution of computations. The Continuation monad adapts CPS to the structure of a monad. Before using the Continuation monad, be sure that you have a firm understanding of continuation-passing style and that continuations represent the best solution to your particular design problem. Many algorithms which require continuations in other languages do not require them in Haskell, due to Haskell's lazy semantics. Abuse of the Continuation monad can produce code that is impossible to understand and maintain.

Continuation style utilities.

T

API for Church-encoded vectors. Implementation of function from Data.Vector.Fixed module uses these function internally in order to provide shortcut fusion.

A continuation accepting an a and producing a b.

Continuous assignment, which occurs in a concurrent context.

A delimited continuation that can be used in a do block.

CPS encoded heterogeneous vectors.

OK, consumed, continue with state s