Language Reference/Built-in entities/Constants

compilation_date	Compilation date
compilation_time	Compilation time
compiler_buildDate	Build date of the compiler
compiler_version	Compiler version number
maxFloatDigits	Maximum supported digits for real domains
null	The default NULL pointer
nullHandle	A constant of type handle with value 0
invalidHandle	A constant of type handle with value −1 (invalid)
platform_bits	Bitness of the compilation platform (32 or 64)
platform_name	Target platform name

compilation_date

Compilation date in the format YYYY-MM-DD.

compilation_date : string = "YYYY-MM-DD".

compilation_time

Compilation time in the format HH:MM:SS (24-hour clock).

compilation_time : string = "HH:MM:SS".

compiler_buildDate

Build date of the compiler in the format YYYY-MM-DD HH:MM.

compiler_buildDate : string = "YYYY-MM-DD HH:MM".

compiler_version

Compiler version number (value depends on the compiler).

compiler_version = 1100.

maxFloatDigits

Maximum supported value of digits for real domains.

maxFloatDigits = 16.

null

A constant of type pointer with the value 0.

null : pointer = uncheckedConvert(pointer, 0).

null is also implicitly defined on all interfaces as a null pointer of the interface type. If it were defined explicitly, it would look like this:

interface xxx
...
constants
    null : xxx = uncheckedConvert(xxx, null).  % already implicitly defined
...
end interface xxx

Example This example shows how the constant can be used in a clause.

interface xxx
end interface xxx
 
...
clauses
    isNullXxx(X) :-
        xxx::null = X.

nullHandle

A constant of type handle with the value 0.

nullHandle : handle = uncheckedConvert(handle, 0).

invalidHandle

A constant of type handle with the value -1 (invalid for a handle).

invalidHandle : handle = uncheckedConvert(handle, -1).

platform_bits

Bitness of the compilation platform.

platform_bits = 32.
or
platform_bits = 64.

platform_name

Target platform name.

platform_name : string = "Windows 32bits".
or
platform_name : string = "Windows 64bits".