dfunc library

Classes

Either<L, R>
Represents a value that can be either of type L or of type R. Usually L is assumed to be of Error type and R of Right type, e.g.:
Eithers
Left<L, R>

Functions

always<T>(T value) → T Function([dynamic _])
Returns a function that always returns the given value.
castOrElse<T>(dynamic t, T orElse()) → T
Safely casts t to type T.
castOrNull<T>(dynamic t) → T?
Safely casts t to type T.
catches<A extends Object>(Func0<A?> a) → A?
Catches all exceptions and returns null in case of an exception.
compact<T>(Iterable<T?> items) → Iterable<T>
Filters out all null values from Iterable.
complement<A>(Predicate<A> f) → Predicate<A>
Takes a function f and returns a function g such that if called with the same argument when f returns true, g returns false and when f returns a false g returns true.
curry<A, B, C>(Func2<A, B, C> f) → Func1<A, Func1<B, C>>
F([dynamic _]) → bool
A function that always returns false. Any passed in parameter is ignored.
groupBy<K, V>(Func1<V, K> getKey, Iterable<V> items) → Map<K, List<V>>
Splits an iterable into sub-lists stored in a map, based on result of calling getKey function on each element of items, and grouping the results according to values returned.
identity<T>(T value) → T
A function that returns the parameter supplied to it. Can be used e.g. as a placeholder function.
ignore([dynamic _]) → void
Ignores passed argument.
isEmpty(String? s) → bool
Returns true if passed string is null or empty;
left<L, R>(L value) → Either<L, R>
Sortcut for Either.left.
lift<A extends Object, B extends Object>(Func1<B, A?> f) → Func1<B?, A?>
Transforms function f taking non-nullable argument into a function taking nullable argument.
limit(int maxLength) → String Function(String?)
Returns functions that limits passed string to the maxLength number of characters.
map<T, S>(S f(T)) → Mapper<T, S>
Creates a mapper, i.e. a function that takes a list of S and maps it into a list of T.
map2<A extends Object, B extends Object, C extends Object>(A? a, B? b, Func2<A, B, C?> f) → C?
Combines to nullable values a and b using a binary function f. If either nullable value is null, the result is null.
mapBy<K, V>(Func1<V, K> getKey, Iterable<V> items) → Map<K, V>
Creates map from items. Keys of the map are created by applying getKey function to the corresponding item of the list.
mapIndexed<T, E>(Func2<int, E, T> f, Iterable<E> items) → Iterable<T>
Returns a new Iterable with elements that are created by calling f on each element of items in iteration order and provides position of the element as a first argument of f.
partial1<A, B, C>(A a, Func2<A, B, C> f) → Func1<B, C>
pipe2<S, T, U>(Func1<S, T> f1, Func1<T, U> f2) → Func1<S, U>
Performs left-to-right function composition.
pipe3<S, T, U, V>(Func1<S, T> f1, Func1<T, U> f2, Func1<U, V> f3) → Func1<S, V>
Performs left-to-right function composition.
Shortcut for Either.right.
sequence<A extends Object>(List<A?> xs) → List<A>?
Combines a list of nullable values into one nullable list with non-nullable values. If any of the values is null, the result is null.
substring(String? str, int startIndex, [int? endIndex]) → String
Safely returns the substring of this string that extends from startIndex, inclusive, to endIndex, exclusive.
sum<T extends num>(Iterable<T> items) → T
Returns sum of all elements in Iterable. Returns 0 if iterable is empty.
T([dynamic _]) → bool
A function that always returns true. Any passed in parameter is ignored.
traverse<A extends Object, B extends Object>(List<A?> xa, Func1<A, B?> f) → List<B>?
Maps over the list and applies f to each non-null element. Returns the list of non-null values if all elements and results of applying f are not null, otherwise returns null.
tryEither<T>(T block(BindEither bind)) → Result<T>
tryEitherAsync<T>(FutureOr<T> block(BindEither bind)) → AsyncResult<T>
uncurry<A, B, C>(Func1<A, Func1<B, C>> f) → Func2<A, B, C>
zip2<A, B>(Iterable<A> a, Iterable<B> b) → Iterable<(A, B)>
Creates an iterable of Product2<A, B> by pairing up equally positioned items from both iterables a and b. The returned iterable is truncated to the length of the shorter of the two iterables.

Typedefs

AsyncEither<L, R> = Future<Either<L, R>>
AsyncResult<T> = Future<Result<T>>
BindEither = T Function<T>(Result<T>)
Func0<A> = A Function()
Func1<A, B> = B Function(A)
Func2<A, B, C> = C Function(A, B)
Mapper<T, S> = Iterable<S> Function(Iterable<T>)
Predicate<A> = bool Function(A)
Result<T> = Either<Exception, T>
SeparatorBuilder<A, B> = B Function(A prev, A next)
Signature for the separator builder in intersperseWith method.
Transformer<A, B> = B Function(A)
Function that transforms object of type A into object of type B.