Evaluates the underlying computation and returns the result.
Evaluates the underlying computation and returns the result.
NOTE: this can throw exceptions.
Creates a new Coeval that will expose any triggered error from the source.
Dematerializes the source's result from a Try
.
Returns a new Coeval
in which f
is scheduled to be run on completion.
Returns a new Coeval
in which f
is scheduled to be run on completion.
This would typically be used to release any resources acquired by this
Coeval
.
Returns a failed projection of this coeval.
Returns a failed projection of this coeval.
The failed projection is a Coeval
holding a value of type Throwable
,
emitting the error yielded by the source, in case the source fails,
otherwise if the source succeeds the result will fail with a
NoSuchElementException
.
Creates a new Coeval
by applying a function to the successful result
of the source, and returns a new instance equivalent
to the result of the function.
Given a source Coeval that emits another Coeval, this function flattens the result, returning a Coeval equivalent to the emitted Coeval by the source.
Triggers the evaluation of the source, executing the given function for the generated element.
Triggers the evaluation of the source, executing the given function for the generated element.
The application of this function has strict behavior, as the coeval is immediately executed.
Returns a new task that upon evaluation will execute
the given function for the generated element,
transforming the source into a Coeval[Unit]
.
Returns a new task that upon evaluation will execute
the given function for the generated element,
transforming the source into a Coeval[Unit]
.
Similar in spirit with normal foreach, but lazy, as obviously nothing gets executed at this point.
Returns a new Coeval that applies the mapping function to the element emitted by the source.
Creates a new Coeval that will expose any triggered error from the source.
Memoizes (caches) the result of the source and reuses it on
subsequent invocations of value
.
Memoizes (caches) the result of the source and reuses it on
subsequent invocations of value
.
The resulting coeval will be idempotent, meaning that evaluating the resulting coeval multiple times will have the same effect as evaluating it once.
memoizeOnSuccess for a version that only caches successful results
Memoizes (cache) the successful result of the source
and reuses it on subsequent invocations of value
.
Memoizes (cache) the successful result of the source
and reuses it on subsequent invocations of value
.
Thrown exceptions are not cached.
The resulting coeval will be idempotent, but only if the result is successful.
memoize for a version that caches both successful results and failures
Creates a new coeval that in case of error will fallback to the given backup coeval.
Creates a new coeval that will handle any matching throwable that this coeval might emit.
Creates a new coeval that will handle any matching throwable that this coeval might emit.
See onErrorRecover for the version that takes a partial function.
Creates a new coeval that will handle any matching throwable that this coeval might emit by executing another coeval.
Creates a new coeval that will handle any matching throwable that this coeval might emit by executing another coeval.
See onErrorRecoverWith for the version that takes a partial function.
Creates a new coeval that on error will try to map the error to another value using the provided partial function.
Creates a new coeval that on error will try to map the error to another value using the provided partial function.
See onErrorHandle for the version that takes a total function.
Creates a new coeval that will try recovering from an error by matching it with another coeval using the given partial function.
Creates a new coeval that will try recovering from an error by matching it with another coeval using the given partial function.
See onErrorHandleWith for the version that takes a total function.
Creates a new coeval that in case of error will retry executing the source again and again, until it succeeds.
Creates a new coeval that in case of error will retry executing the source again and again, until it succeeds.
In case of continuous failure the total number of executions
will be maxRetries + 1
.
Creates a new coeval that in case of error will retry executing the source again and again, until it succeeds.
Creates a new coeval that in case of error will retry executing the source again and again, until it succeeds.
In case of continuous failure the total number of executions
will be maxRetries + 1
.
Given a predicate function, keep retrying the coeval until the function returns true.
Evaluates the underlying computation and returns the result or any
triggered errors as a Scala Either
, where Right(_)
is for successful
values and Left(_)
is for thrown errors.
Evaluates the underlying computation and returns the result or any triggered errors as a Coeval.Attempt.
Evaluates the underlying computation and returns the
result or any triggered errors as a scala.util.Try
.
Creates a new Coeval
by applying the 'fa' function to the successful result of
this future, or the 'fe' function to the potential errors that might happen.
Creates a new Coeval
by applying the 'fa' function to the successful result of
this future, or the 'fe' function to the potential errors that might happen.
This function is similar with map, except that it can also transform errors and not just successful results.
function that transforms a successful result of the receiver
function that transforms an error of the receiver
Creates a new Coeval
by applying the 'fa' function to the successful result of
this future, or the 'fe' function to the potential errors that might happen.
Creates a new Coeval
by applying the 'fa' function to the successful result of
this future, or the 'fe' function to the potential errors that might happen.
This function is similar with flatMap, except that it can also transform errors and not just successful results.
function that transforms a successful result of the receiver
function that transforms an error of the receiver
Evaluates the underlying computation and returns the result.
Evaluates the underlying computation and returns the result.
NOTE: this can throw exceptions.
Alias for apply.
Zips the values of this
and that
coeval, and creates a new coeval
that will emit the tuple of their results.
Zips the values of this
and that
and applies the given
mapping function on their results.
Dematerializes the source's result from a Coeval.Attempt.
Dematerializes the source's result from a Coeval.Attempt.
Deprecated, please use Coeval#dematerialize or just flatMap.
The reason for the deprecation is the naming alignment
with the Cats ecosystem, where Attempt
is being used
as an alias for Either[Throwable, A]
.
(Since version 2.3.0) Use Coeval#dematerialize or Coeval#flatMap
Creates a new Coeval that will expose any triggered error from the source.
Creates a new Coeval that will expose any triggered error from the source.
Deprecated, please use Coeval#attempt or Coeval#materialize.
The reason for the deprecation is the naming alignment
with the Cats ecosystem, where Attempt
is being used
as an alias for Either[Throwable, A]
.
(Since version 2.3.0) Use Coeval#attempt or Coeval#materialize
Coeval
represents lazy computations that can execute synchronously.Word definition and origin:
Coeval
is the dual of an expression that evaluates to anA
.There are three evaluation strategies:
The
Once
andAlways
are both lazy strategies whileNow
andError
are eager.Once
andAlways
are distinguished from each other only by memoization: once evaluatedOnce
will save the value to be returned immediately if it is needed again.Always
will run its computation every time.Both
Now
andError
are represented by the Attempt trait, a sub-type of Coeval that can be used as a replacement for Scala's ownTry
type.Coeval
supports stack-safe lazy computation via the .map and .flatMap methods, which use an internal trampoline to avoid stack overflows. Computation done within .map and .flatMap is always done lazily, even when applied to aNow
instance.