Result
Related Docs:
object Result
| package validation
[use case]
[use case] Combines two Results in a builder, eventually accumulating invalids.
Combines two Results in a builder, eventually accumulating invalids.
This is the Applicative Builder of the valid result.
the other valid type
the other Result this one should be combined with
a builder to eventually apply two Results
[use case]
[use case] Applies a function in the Result context to the valid value,
accumulating invalids.
Applies a function in the Result context to the valid value,
accumulating invalids.
This is the Applicative Functor of the valid Result.
the resulting valid type
the function in the Result context
the valid result if this and f are valid
or invalid if one of each is invalid
or both invalid values accumulated
Sets the valid value to x and discards the previous value
if this is a valid Result.
Sets the valid value to x and discards the previous value
if this is a valid Result.
the resulting valid type
the new valid value
the result with the valid value set to x
0.2.0
Transforms the value of this Result.
Transforms the value of this Result.
the resulting invalid type
the resulting valid type
the function to transform an invalid value
the function to transform a valid value
the result with either the valid or invalid value transformed
[use case]
[use case] Tests for membership on the valid Result
Tests for membership on the valid Result
true if this Result has x as valid value
true if this Result is valid and satisfies the predicate p
[use case] Filters the valid value of this Result.
[use case] Continues validation with the provided function
if this is a valid Result.
Continues validation with the provided function
if this is a valid Result.
flatMap does not accumulate errors.
If you want to do so, use and instead.
This is the Monadic Bind through the valid value.
the resulting valid type
the function to continue with
the result of applying f over the valid value in the Result context
Folds this Result into a value by applying the first function if this
is a Invalid or the second function if this is a Valid.
Folds this Result into a value by applying the first function if this
is a Invalid or the second function if this is a Valid.
This is the Catamorphism.
the resulting type
the function to apply in the invalid case
the function to apply in the valid case
the result of one of the two functions
A left fold over the valid value.
A left fold over the valid value.
the resulting type
the initial accumulator
reducer function of the accumulator and the valid value
b if this is Invalid, otherwise the result of applying f
A right fold over the valid value.
A right fold over the valid value.
the resulting type
the initial accumulator
reducer function of the valid value and the accumulator
b if this is Invalid, otherwise the result of applying f
true if this Result is invalid or the valid value satisfies the predicate p
[use case]
[use case]
Curried fold that starts with the invalid part.
Maps over the invalid value of this Result.
Maps over the invalid value of this Result.
This is the Functor over the invalid side.
the resulting invalid type
the function to apply if this Result is invalid
the result of the function application in the Result context
true if this is an invalid Result
true if this is a valid Result
Maps over the valid value of this Result.
Maps over the valid value of this Result.
This is the Functor over the valid side.
the resulting valid type
the function to apply if this Result is valid
the result of the function application in the Result context
[use case]
[use case]
[use case] Transforms an invalid Result into a valid one.
Transforms an invalid Result into a valid one.
the function to transform an invalid value into a valid one
a result that is always valid
[use case] Transforms an invalid Result into a valid one.
Transforms an invalid Result into a valid one.
the function to transform all invalid values into a valid one
a result that is always valid
[use case] Continues validation with the provided function
if this is an invalid Result.
Continues validation with the provided function
if this is an invalid Result.
This is the Monadic Bind through the invalid value.
the resulting invalid type
the function to continue with
the result of applying f over the invalid value in the Result context
[use case]
[use case]
Curried fold that starts with the valid part.
[use case]
Discards the valid value if this is a valid Result.
Discards the valid value if this is a valid Result.
the result with the valid value set to Unit
0.2.0
[use case] Combines two Result by zipping their valid values together,
accumulating errors.
Methods to access or extract a value from this Result.
Methods to transform the value of this Result.
Methods to test the value of this Result for some properties.
Methods to translate this Result into a different structure.
Methods to combine multiple Results.
Represents a value of one of two states:
Valid(a)Invalid(e)It is similar to Either or a more generic Try.
Motivation
Scalas
Eitheris unbiased, meaning it treats its two sides equally and requires one to explicitly state on which side one wants to work on. More often that not, one side is representing the error or invalid part and one side representing the success or valid part.Resultsets the invalid side on the left and the valid side on the right and assumes, that one wants to primarily work on the right/valid side. This is similar toTry, which fixes the invalid type toThrowable.Example:
Both,
EitherandTry, cannot accumulate errors, but are typically aborting with the first failure, making them disadvantageous for parsing and validating data on system boundaries. For example, parsing a JSON data structure can lead to multiple issues and it is good measure to report as many errors as you can back to the user. WithEitherorTry, only one error at the time gets reported, leading to the user to submit a fixed version only to encounter, that they have to fixed yet another error.Resultcan accumulate errors and thus allows to report as many of them as possible. There are multiple ways to combine two or moreResults, for a detailed description, see their respective documentation.Example:
the
Invalidtypethe
Validtype0.1.0