65.1.4 The array form

Arrays in general are finite, indexed sets of unityped data. That is (informally), a contiguous piece of memory with data slots, where the data slots all have the same type and are enumerated from 0 to size-1. Accessing a certain slot is achieved by passing its slot number to the accessor function.

The syntax for this type-modification is the form '(array type size), with size being a positive integer. For example the FFI-type '(array int 20) would be equivalent to the C-syntax ‘int some_undefined_name[20]’.