Stream

Object Hierarchy:

Description:

    var list = new ArrayList<string> (GLib.str_equal);
    list.add ("banana");
    list.add ("apple");
    list.add ("cherry");

    var result = Stream.fromList<string> (list)
        .filter ((s) => { return s.length > 5; })
        .sorted ((a, b) => { return strcmp (a, b); })
        .toList ();
    // result: ["banana", "cherry"]

Content:

Static methods:

• public static Stream<T> empty<T> ()
  Creates an empty Stream.
• public static Stream<T> fromList<T> (ArrayList<T> list)
  Creates a Stream from an ArrayList.
• public static Stream<T> generate<T> (owned SupplierFunc<T> fn, int limit)
  Creates a Stream by invoking a supplier function repeatedly.
• public static Stream<T> of<T> (T[] values)
  Creates a Stream from an array.
• public static Stream<int> range (int start, int end)
  Creates a Stream of integers from start (inclusive) to end (exclusive).
• public static Stream<int> rangeClosed (int start, int end)
  Creates a Stream of integers from start (inclusive) to end (inclusive).

Methods:

• public bool allMatch (owned PredicateFunc<T> fn)
  Returns whether all elements match the predicate. Returns true for an empty stream.
• public bool anyMatch (owned PredicateFunc<T> fn)
  Returns whether any element matches the predicate.
• public double? average (owned DoubleMapFunc<T> fn)
  Returns the average of mapped double values.
• public int count ()
  Returns the number of elements in this stream.
• public Stream<T> distinct (EqualFunc<T> equal)
  Returns a Stream with duplicate elements removed. Uses the provided equality function for comparison.
• public Stream<T> dropWhile (owned PredicateFunc<T> fn)
  Returns a Stream skipping elements while the predicate is true, then includes all remaining elements.
• public Stream<T> filter (owned PredicateFunc<T> fn)
  Returns a Stream containing only elements that match the predicate.
• public T findFirst ()
  Returns the first element, or null if the stream is empty.
• public T findLast ()
  Returns the last element, or null if the stream is empty.
• public T firstOr (T fallback)
  Returns the first element or the fallback value if empty.
• public Stream<U> flatMap<U> (owned MapFunc<T,Stream<U>> fn)
  Returns a Stream where each element is transformed into another Stream and then flattened.
• public void forEach (owned ConsumerFunc<T> fn)
  Executes an action for each element.
• public HashMap<K,ArrayList<T>> groupBy<K> (owned MapFunc<T,K> keyFn, HashFunc<K> hash_func, EqualFunc<K> equal_func)
  Groups elements by a key extraction function.
• public Result<string,Error> joining (string delimiter = "")
  Joins stream elements into a string with a delimiter.
• public string joiningWith (owned MapFunc<T,string> toStr, string delimiter = "")
  Joins stream elements into a string with a custom formatter.
• public Stream<T> limit (int n)
  Returns a Stream limited to the first n elements.
• public Stream<U> map<U> (owned MapFunc<T,U> fn)
  Returns a Stream with each element transformed by the function.
• public T max (owned ComparatorFunc<T> cmp)
  Returns the maximum element using the given comparator, or null if the stream is empty.
• public T min (owned ComparatorFunc<T> cmp)
  Returns the minimum element using the given comparator, or null if the stream is empty.
• public bool noneMatch (owned PredicateFunc<T> fn)
  Returns whether no elements match the predicate. Returns true for an empty stream.
• public Pair<ArrayList<T>,ArrayList<T>> partitionBy (owned PredicateFunc<T> fn)
  Partitions elements into two lists by a predicate.
• public Stream<T> peek (owned ConsumerFunc<T> fn)
  Executes an action on each element and returns the same Stream. Useful for debugging pipeline contents.
• public U reduce<U> (U initial, owned ReduceFunc<T,U> fn)
  Folds the stream into a single value by applying the accumulator function to each element, starting from the initial value.
• public Stream<T> skip (int n)
  Returns a Stream with the first n elements skipped.
• public Stream<T> sorted (owned ComparatorFunc<T> cmp)
  Returns a Stream sorted using the given comparator.
• public double sumDouble (owned DoubleMapFunc<T> fn)
  Returns the sum of mapped double values.
• public int sumInt (owned MapFunc<T,int> fn)
  Returns the sum of mapped integer values.
• public Stream<T> takeWhile (owned PredicateFunc<T> fn)
  Returns a Stream of elements taken while the predicate is true. Stops at the first element that does not match.
• public T[] toArray ()
  Collects the stream elements into an array.
• public HashSet<T> toHashSet (HashFunc<T> hash_func, EqualFunc<T> equal_func)
  Collects stream elements into a HashSet.
• public ArrayList<T> toList ()
  Collects the stream elements into an ArrayList.
• public HashMap<K,V> toMap<K,V> (owned MapFunc<T,K> keyFn, owned MapFunc<T,V> valFn, HashFunc<K> hash_func, EqualFunc<K> equal_func)
  Collects stream elements into a HashMap.

Inherited Members: