package cfstream

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in-package search v0.2.0

cfstream
- CFStream
  - Stream
    
    Infix
    
    Or_error
    
    Result
  - Streamable
    
    S
    
    S2

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Higher-order functions for streams of results

The functions in this module can be used to iterate on a stream of results with a function that only considers the non-error case. The iterated function thus doesn't need to do the pattern match on each Result value.

For each kind of iteration, two versions are proposed. One for total functions (that is, functions that cannot fail), the other for partial functions (they are assumed to return a Result in this case).

type ('a, 'e) t = ('a, 'e) Core_kernel.Result.t Stream.t

val all : 
  ('a, 'e) t ->
  f:('a Stream.t -> ('b, 'e) Core_kernel.Result.t) ->
  ('b, 'e) Core_kernel.Result.t

val all' : ('a, 'e) t -> f:('a Stream.t -> 'b) -> ('b, 'e) Core_kernel.Result.t

val to_exn : ('a, 'e) t -> error_to_exn:('e -> exn) -> 'a Stream.t

val map : ('a, 'e) t -> f:('a -> ('b, 'e) Core_kernel.Result.t) -> ('b, 'e) t

map' rs ~f maps Ok results with a partial function f

val map' : ('a, 'e) t -> f:('a -> 'b) -> ('b, 'e) t

map rs ~f maps Ok results with a total function f

val map2_exn : 
  ('a, 'e) t ->
  ('b, 'e) t ->
  f:('a -> 'b -> ('c, 'e) Core_kernel.Result.t) ->
  ('c, 'e) t

Generalization of map with two streams of results. If the two streams fail simultaneously, one of the two errors is propagated.

val map2_exn' : ('a, 'e) t -> ('b, 'e) t -> f:('a -> 'b -> 'c) -> ('c, 'e) t

Analoguous of map2_exn for total functions

val fold : 
  ('a, 'e) t ->
  init:'b ->
  f:('b -> 'a -> ('b, 'e) Core_kernel.Result.t) ->
  ('b, 'e) Core_kernel.Result.t

fold rs ~init ~f computes a value by iterating f on each Ok element of rs starting from init. The computation stops with an Error case as soon as one is met on the stream, or when f returns one.

val fold' : 
  ('a, 'e) t ->
  init:'b ->
  f:('b -> 'a -> 'b) ->
  ('b, 'e) Core_kernel.Result.t

Same as fold, but for total functions.