EnumerationQuest

Avoids multiple enumeration.

Introduction

EnumerationQuest library allows the evaluation of multiple properties of an IEnumerable in a single enumeration.

It's as simple as that:

    var (min, max) = enumerable.GetMin().AndMax();

Tell me more

EnumerationQuest provides the same methods as LINQ to Objects to evaluate properties of IEnumerable.
But unlike LINQ, EnumerationQuest allows the evaluation of several properties at once; that's it, in a single enumeration.

To achieve this, EnumerationQuest uses fluent pattern to construct an EnumerationRequests object.

• The first method is called on the IEnumerable source object with the Get prefix.
• The following ones are called on EnumerationRequests object with the And prefix.
• The enumeration and the evaluations are performed at the deconstruction of the EnumerationRequests object.

Et voilà:

    var (min, avg, max, count, evenValues) = e.GetMin()
                                              .AndAverage()
                                              .AndMax()
                                              .AndCount()
                                              .And(o => o.Select(i => i % 2 == 0).ToList());

Available methods

• Aggregate: applies an accumulator function over a sequence.
• All: determines whether all elements of a sequence satisfy a condition.
• Any: determines whether any element of a sequence exists or satisfies a condition.
• Average: computes the average of a sequence of numeric values.
• Contains: determines whether a sequence contains a specified element.
• Count: returns the number of elements in a sequence; or the number of elements that satisfy a condition.
• DelimitedString (aka String.Join): concatenates the elements of a sequence, inserting the specified separator between each element.
• ElementAt: returns the element at a specified index in a sequence.
• ElementsAt: returns the elements at the specified indices in a sequence.
• ElementAtOrDefault: returns the element at a specified index in a sequence or a default value if the index is out of range.
• First: returns the first element of a sequence; or the first element that satisfies a condition.
• FirstOrDefault: returns the first element of a sequence; or the first element that satisfies a condition; or a default value if such an element does not exist .
• Get/And: transform the sequence into an IObservable and allow to use react extensions methods.
• HasDuplicates: determines whether a sequence contains a duplicate element.
• IndexOf (from List<T> and Array): returns the zero-based index of the first occurrence of a value in a sequence.
• IndicesOf: returns the zero-based indices of all occurrences of a value in a sequence.
• Last: returns the last element of a sequence; or the last element that satisfies a condition.
• LastOrDefault: returns the last element of a sequence; or the last element that satisfies a condition; or a default value if such an element does not exist .
• LongCount: returns a long that represent the number of elements in a sequence; or the number of elements that satisfy a condition.
• Max: returns the maximum value in a sequence of value; or a sequence of transformed values.
• MaxBy: returns the maximum value in a sequence according to a specified key.
• MaximumsBy: returns the maximums values in a sequence according to a specified key.
• Min: returns the minimum value in a sequence of value; or a sequence of transformed values.
• MinBy: returns the minimum value in a sequence according to a specified key.
• MinimumsBy: returns the minimums value in a sequence according to a specified key.
• SequenceEqual: determines whether two sequences are equal according to an equality comparer.
• Single: returns the single element of a sequence; or the single element that satisfies a condition.
• SingleOrDefault: returns the single element of a sequence; or the single element that satisfies a condition; or a default value if such an element does not exist .
• Slice (replace Skip, SkipLast, Take and TakeLast): takes a specified range of contiguous elements from a sequence.
• Sum: computes the sum of a sequence of numeric values.
• ToDictionary: creates a Dictionary<TKey,TValue> from a sequence.
• ToHashSet: creates a HashSet<TValue> from a sequence.
• ToLookup: creates a ILookup<TKey,TValue> from a sequence.

Status

See the todo.md file to see the current status of the library.