Method AllSomeOrNone

Namespace

SodaFlow.Functional

Assembly

SodaFlow.Functional.dll

AllSomeOrNone<T>(IEnumerable<Maybe<T>>?)

Turns a sequence of values that can be missing into a sequence that can be missing, which has a value only when each entry was.

[Pure]
public static Maybe<IEnumerable<T>> AllSomeOrNone<T>(this IEnumerable<Maybe<T>>? o)

Parameters

o IEnumerable<Maybe<T>>

The sequence to collect. A null sequence counts as empty.

Returns

Maybe<IEnumerable<T>>

All the values if each entry had one, and no value if any entry did not. An empty sequence gives an empty sequence rather than no value.

Type Parameters

T

The type of the values in the sequence.

Remarks

Unlike WhereSome<T>(IEnumerable<Maybe<T>>?), this enumerates the source immediately. No code can know if the result has a value without a read to the end of it.

AllSomeOrNone<T, TResult>(IEnumerable<T>?, Func<T, Maybe<TResult>>)

Applies a function which can give no value to each element of a sequence, and collects the results only when each one has a value.

[Pure]
public static Maybe<IEnumerable<TResult>> AllSomeOrNone<T, TResult>(this IEnumerable<T>? o, Func<T, Maybe<TResult>> f)

Parameters

o IEnumerable<T>

The sequence to map. A null sequence counts as empty.

f Func<T, Maybe<TResult>>

Applied to each element in turn.

Returns

Maybe<IEnumerable<TResult>>

All the results if f produced a value for each element, and no value if it did not give one for any. An empty sequence gives an empty sequence rather than no value.

Type Parameters

T

The type of the values in the sequence.

TResult

The type of the values the function produces.

Remarks

This is the all-or-nothing counterpart to Choose<T, TResult>(IEnumerable<T>?, Func<T, Maybe<TResult>>) , which keeps whatever it can get and discards the others. Use this one where one element that fails makes the full result meaningless. An example is a parse of a file of numbers, and not a selection of the numbers in a file of mixed lines. Like the other overload this enumerates the source immediately. f runs on each element, and a value of none from one element does not stop it. Thus, it must not be dependent on a stop before the end.