Difference between revisions of "Language Reference/Built-in entities/Constants"

From wiki.visual-prolog.com
(interface::null)
(Review)
 
Line 2: Line 2:
|-
|-
|[[#compilation_date|compilation_date]]
|[[#compilation_date|compilation_date]]
|Compilation date.
|Compilation date
|-
|-
|[[#compilation_time|compilation_time]]
|[[#compilation_time|compilation_time]]
|Compilation time.
|Compilation time
|-
|-
|[[#compiler_buildDate|compiler_buildDate]]
|[[#compiler_buildDate|compiler_buildDate]]
|Build date of a compiler.
|Build date of the compiler
|-
|-
|[[#compiler_version|compiler_version]]
|[[#compiler_version|compiler_version]]
|A compiler version.
|Compiler version number
|-
|-
|[[#maxFloatDigits|maxFloatDigits]]
|[[#maxFloatDigits|maxFloatDigits]]
|Defines the maximal value of "digits", which is supported by the compiler.
|Maximum supported <vp>digits</vp> for <vp>real</vp> domains
|-
|-
|[[#null|null]]
|[[#null|null]]
|The default NULL pointer.
|The default NULL pointer
|-
|-
|[[#nullHandle|nullHandle]]
|[[#nullHandle|nullHandle]]
|A special constant of a handle type with the zero value.
|A constant of type handle with value 0
|-
|-
|[[#invalidHandle|invalidHandle]]
|[[#invalidHandle|invalidHandle]]
|A special constant of a handle type with the invalid (-1) value.
|A constant of type handle with value −1 (invalid)
|-
|-
|[[#platform_bits|platform_bits]]
|[[#platform_bits|platform_bits]]
|Defines the digital capacity of compilation platform.
|Bitness of the compilation platform (32 or 64)
|-
|-
|[[#platform_name|platform_name]]
|[[#platform_name|platform_name]]
|Defines the target platform name.
|Target platform name
|}
|}


==== compilation_date ====
==== compilation_date ====


Compilation date. Here ''YYYY'' means the number of a year, ''MM'' means a month number, and ''DD'' means a day number.
Compilation date in the format ''YYYY-MM-DD''.


<vip>compilation_date : string = "YYYY-MM-DD".</vip>
<vip>compilation_date : string = "YYYY-MM-DD".</vip>
Line 40: Line 40:
==== compilation_time ====
==== compilation_time ====


Compilation time. Here ''HH'' means hours, ''MM'' means minutes, and ''SS ''means seconds.
Compilation time in the format ''HH:MM:SS'' (24-hour clock).


<vip>compilation_time : string = "HH:MM:SS".</vip>
<vip>compilation_time : string = "HH:MM:SS".</vip>
Line 46: Line 46:
==== compiler_buildDate ====
==== compiler_buildDate ====


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


<vip>compiler_buildDate : string = "YYYY-MM-DD HH:MM".</vip>
<vip>compiler_buildDate : string = "YYYY-MM-DD HH:MM".</vip>
Line 52: Line 52:
==== compiler_version ====
==== compiler_version ====


A compiler version. This value depends upon the compiler version.
Compiler version number (value depends on the compiler).


<vip>compiler_version = 6003.</vip>
<vip>compiler_version = 1100.</vip>


==== maxFloatDigits ====
==== maxFloatDigits ====


Defines the maximal value of "digits", which is supported by the compiler.
Maximum supported value of <vp>digits</vp> for <vp>real</vp> domains.


<vip>maxFloatDigits = 16.</vip>
<vip>maxFloatDigits = 16.</vip>
Line 68: Line 68:
<vip>null : pointer = uncheckedConvert(pointer, 0).</vip>
<vip>null : pointer = uncheckedConvert(pointer, 0).</vip>


<vp>null</vp> is also implicitly defined on all interfaces.  It is a null pointer of the type the interface has. This is how it would look if the constant was defined '''explicitly''':
<vp>null</vp> 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:


<vip>
<vip>
Line 74: Line 74:
...
...
constants
constants
     null : xxx = uncheckedConvert(xxx, null).  % this constant is already implicitly defined
     null : xxx = uncheckedConvert(xxx, null).  % already implicitly defined
...
...
end interface xxx
end interface xxx
Line 99: Line 99:
==== invalidHandle ====
==== invalidHandle ====


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


<vip>invalidHandle : handle = uncheckedConvert(handle, -1).</vip>
<vip>invalidHandle : handle = uncheckedConvert(handle, -1).</vip>
Line 105: Line 105:
==== platform_bits ====
==== platform_bits ====


Defines the digital capacity of compilation platform.
Bitness of the compilation platform.


<vip>platform_bits = 32.
<vip>platform_bits = 32.
Line 113: Line 113:
==== platform_name ====
==== platform_name ====


Defines the target platform name.
Target platform name.


<vip>platform_name : string = "Windows 32bits".
<vip>platform_name : string = "Windows 32bits".

Latest revision as of 15:34, 20 August 2025

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".
Retrieved from "https://wiki.visual-prolog.com/index.php?title=Language_Reference/Built-in_entities/Constants&oldid=4995"