The sum of a collection of actions, generalizing concat.

This generalizes the list-based concat function.

Randomly uses one of the given generators. The input list must be non-empty.

The union of a list of maps.
> unions [(fromList [(5, "a"), (3, "b")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "A3"), (3, "B3")])]
> == fromList [(3, "b"), (5, "a"), (7, "C")]
> unions [(fromList [(5, "A3"), (3, "B3")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "a"), (3, "b")])]
> == fromList [(3, "B3"), (5, "A3"), (7, "C")]

Combines all parsers in the specified list.

Combines all parsers in the specified list.

Concatenate a list of lists.

The sum of a collection of actions, generalizing concat.

The union of a list of maps, with a combining operation.
> unionsWith (++) [(fromList [(5, "a"), (3, "b")]), (fromList [(5, "A"), (7, "C")]), (fromList [(5, "A3"), (3, "B3")])]
> == fromList [(3, "bB3"), (5, "aAA3"), (7, "C")]

intercalate xs xss is equivalent to (concat (intersperse xs xss)). It inserts the list xs in between the lists in xss and concatenates the result.

Evaluate each action in the sequence from left to right, and ignore the results.

The transpose function transposes the rows and columns of its argument. For example,
> transpose [[1,2,3],[4,5,6]] == [[1,4],[2,5],[3,6]]

The concatenation of all the elements of a container of lists.

One or none.