This chapter describes the Objective Caml core library, which is
composed of declarations for built-in types and exceptions, plus
the module Pervasives that provides basic operations on these
built-in types. The Pervasives module is special in two ways:
The declarations of the built-in types and the components of
module Pervasives are printed one by one in typewriter font,
followed by a short comment. All library modules and the
components they provide are indexed at the end of this report.
The following built-in types and predefined exceptions are
always defined in the compilation environment, but are not part
of any module. As a consequence, they can only be referred by
their short names. The type of integer numbers. The type of
characters. The type of character strings. The type of floating-
point numbers. type bool = false | true The type of booleans
(truth values). type unit = () The type of the unit value. The
type of exception values. type 'a array The type of arrays whose
elements have type 'a. type 'a