a state of N India: the most populous state; originated in 1877 with the merging of Agra and Oudh as the United Provinces; augmented by the states of Rampur, Benares, and Tehri-Garhwal in 1949; the N Himalayan region passed to the new state of Uttaranchal (now Uttarakhand) in 2000; now consists mostly of the Upper Ganges plain; agricultural.
Haskell is a modern, standard, non-strict, purely-functional programming language. It provides all the features sketched above, including polymorphic typing, lazy evaluation and higher-order functions. It also has an innovative type system which supports a systematic form of overloading and a module system.
Haskell'98 supports just one array constructor type, namely Array, which gives you immutable boxed arrays. Immutable means that these arrays, like any other pure functional data structure, have contents fixed at construction time. You can't modify them, only query.