5.2 Values
This section describes the kinds of values that are manipulated by
Caml Light programs.
5.2.1 Base values
Integer numbers
Integer values are integer numbers from -230 to 230-1, that
is -1073741824 to 1073741823. The implementation may support a
wider range of integer values: on 64-bit platforms, the current
implementation supports integers ranging from -262 to 262-1.
Floating-point numbers
Floating-point values are numbers in floating-point representation.
The current implementation uses double-precision floating-point
numbers conforming to the IEEE 754 standard, with 53 bits of mantissa
and an exponent ranging from -1022 to 1023.
Characters
Character values are represented as 8-bit integers between 0 and 255.
Character codes between 0 and 127 are interpreted following the ASCII
standard. The current implementation interprets character codes
between 128 and 255 following the ISO 8859-1 standard.
Character strings
String values are finite sequences of characters. The current
implementation supports strings containing up to 224 - 6
characters (16777210 characters).
5.2.2 Tuples
Tuples of values are written (v1, ..., vn), standing for the
n-tuple of values v1 to vn. The current implementation
supports tuple of up to 222 - 1 elements (4194303 elements).
5.2.3 Records
Record values are labeled tuples of values. The record value written
{ label1 = v1; ...; labeln = vn } associates the value
vi to the record label labeli, for i = 1 ... n. The current
implementation supports records with up to 222 - 1 fields
(4194303 fields).
5.2.4 Arrays
Arrays are finite, variable-sized sequences of values of the same
type. The current implementation supports arrays containing to
222 - 1 elements (4194303 elements).
5.2.5 Variant values
Variant values are either a constant constructor, or a pair of a
non-constant constructor and a value. The former case is written
cconstr; the latter case is written ncconstr(v), where v is said
to be the argument of the non-constant constructor ncconstr.
The following constants are treated like built-in constant
constructors:
| Constant |
Constructor |
|
false |
the boolean false |
| true |
the boolean true |
| () |
the ``unit'' value |
| [] |
the empty list |
The current implementation limits the number of distinct constructors
in a given variant type to at most 249.
5.2.6 Functions
Functional values are mappings from values to values.
5.2.7 Objects
Objects are composed of a hidden internal state which is a
record of instance variables, and a set of methods for accessing and
modifying these variables. The structure of an object is described by
the toplevel class that created it.