/// <summary>
/// Determines whether all elements of a sequence satisfy a condition.
/// </summary>
/// <param name="source">An <see cref="IBindableCollection{TElement}" /> that contains the elements to apply the predicate to.</param>
/// <param name="predicate">A function to test each element for a condition.</param>
/// <typeparam name="TSource">The type of the elements of <paramref name="source" />.</typeparam>
/// <returns>
/// true if every element of the source sequence passes the test in the specified
/// predicate, or if the sequence is empty; otherwise, false.
/// </returns>
public static IBindable <bool> All <TSource>(this IBindableCollection <TSource> source, Expression <Func <TSource, bool> > predicate) where TSource : class
{
source.ShouldNotBeNull("source");
predicate.ShouldNotBeNull("predicate");
return(source.Where(predicate).Count()
.Switch()
.Case(count => count >= 1, true)
.Default(false)
.EndSwitch());
}
public PizzaCustomizer(Pizza pizza)
{
_pizza = pizza;
_availableToppings = _pizza.AvailableToppings
.AsBindable()
.Select(topping => new SelectableTopping(topping));
_selectedToppings = _availableToppings
.Where(selectableTopping => selectableTopping.IsSelected)
.Select(selectableTopping => selectableTopping.Topping);
_healthWarningMessage = _selectedToppings.Count()
.Switch()
.Case(0,
"Surely you would like more toppings?")
.Case(toppings => toppings >= 3,
"Too many toppings!")
.Default(
"Perfecto!")
.EndSwitch();
_totalPrice = _selectedToppings.Sum(topping => topping.Price).Project(toppingsTotal => toppingsTotal + pizza.BasePrice);
}
public PizzaCustomizer(Pizza pizza)
{
_pizza = pizza;
_availableToppings = _pizza.AvailableToppings
.AsBindable()
.Select(topping => new SelectableTopping(topping));
_selectedToppings = _availableToppings
.Where(selectableTopping => selectableTopping.IsSelected)
.Select(selectableTopping => selectableTopping.Topping);
_healthWarningMessage = _selectedToppings.Count()
.Switch()
.Case(0,
"Surely you would like more toppings?")
.Case(toppings => toppings >= 3,
"Too many toppings!")
.Default(
"Perfecto!")
.EndSwitch();
_totalPrice = _selectedToppings.Sum(topping => topping.Price).Project(toppingsTotal => toppingsTotal + pizza.BasePrice);
}
/// <summary>Returns a number that represents how many elements in the specified sequence satisfy a condition.</summary>
/// <returns>A number that represents how many elements in the sequence satisfy the condition in the predicate function.</returns>
/// <param name="source">A sequence that contains elements to be tested and counted.</param>
/// <param name="predicate">A function to test each element for a condition.</param>
/// <typeparam name="TSource">The type of the elements of <paramref name="source" />.</typeparam>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="source" /> or <paramref name="predicate" /> is null.</exception>
/// <exception cref="T:System.OverflowException">The number of elements in <paramref name="source" /> is larger than <see cref="F:System.Int32.MaxValue" />.</exception>
public static IBindable <int> Count <TSource>(this IBindableCollection <TSource> source, Expression <Func <TSource, bool> > predicate) where TSource : class
{
predicate.ShouldNotBeNull("predicate");
return(source.Where(predicate).Count());
}
/// <summary>
/// Determines whether any element of a sequence satisfies a condition.
/// </summary>
/// <param name="source">An <see cref="IBindableCollection{TElement}" /> whose elements to apply the predicate to.</param>
/// <param name="predicate">A function to test each element for a condition.</param>
/// <typeparam name="TSource">The type of the elements of <paramref name="source" />.</typeparam>
/// <returns>true if any elements in the source sequence pass the test in the specified predicate; otherwise, false.</returns>
public static IBindable <bool> Any <TSource>(this IBindableCollection <TSource> source, Expression <Func <TSource, bool> > predicate) where TSource : class
{
source.ShouldNotBeNull("source");
predicate.ShouldNotBeNull("predicate");
return(source.Where(predicate).Any());
}
/// <summary>Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.</summary>
/// <returns>default(<typeparamref name="TSource" />) if <paramref name="source" /> is empty or if no element passes the test specified by <paramref name="predicate" />; otherwise, the first element in <paramref name="source" /> that passes the test specified by <paramref name="predicate" />.</returns>
/// <param name="source">An <see cref="IBindableCollection{TElement}" /> to return an element from.</param>
/// <param name="predicate">A function to test each element for a condition.</param>
/// <typeparam name="TSource">The type of the elements of <paramref name="source" />.</typeparam>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="source" /> or <paramref name="predicate" /> is null.</exception>
public static IBindable <TSource> FirstOrDefault <TSource>(this IBindableCollection <TSource> source, Expression <Func <TSource, bool> > predicate) where TSource : class
{
return(source.Where(predicate).FirstOrDefault());
}
/// <summary>Determines whether a sequence contains a specified element by using a specified <see cref="T:System.Collections.Generic.IEqualityComparer`1" />.</summary>
/// <returns>true if the source sequence contains an element that has the specified value; otherwise, false.</returns>
/// <param name="source">A sequence in which to locate a value.</param>
/// <param name="value">The value to locate in the sequence.</param>
/// <param name="comparer">An equality comparer to compare values.</param>
/// <typeparam name="TSource">The type of the elements of <paramref name="source" />.</typeparam>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="source" /> is null.</exception>
public static IBindable <bool> Contains <TSource>(this IBindableCollection <TSource> source, TSource value, IEqualityComparer <TSource> comparer) where TSource : class
{
comparer = comparer ?? new DefaultComparer <TSource>();
value.ShouldNotBeNull("value");
return(source.Where(s => comparer.Equals(s, value)).Any());
}
