Language Reference/Built-in entities/Operators
From wiki.visual-prolog.com
See also Operators.
| Operator | Description | Remark |
|---|---|---|
| ^ | Power operation | Not defined for 64 bit integral numbers |
| - (unary) | Unary minus | |
| *, / | Multiplication and division | |
| div, mod | The quotient and remainder of an integral division rounded towards minus infinity | Not defined for real's |
| quot, rem | The quotient and remainder of an integral division rounded towards zero | Not defined for real's |
| +, - | Addition and subtraction | |
| otherwise | Otherwise expression |
- The operators are listed from highest to lowest precedence
- All division and multiplication operators have same precedence.
- The the power operator is right associative
- All other operators are left associative.
All binary operators takes two arguments of same base type and returns a value of that base type. Operands and result may be converted using ordinary subtype rules.
Integral division
div and quot are different integral division operators.
- div rounds towards minus infinite. mod is the remainder corresponding to div.
- quot rounds towards zero. rem is the remainder corresponding to quot.
For positive results div and quot have same functionality.
The difference can be seen in this table:
| A | B | A div B | A mod B | A quot B | A rem B |
| 15 | 7 | 2 | 1 | 2 | 1 |
| -15 | 7 | -3 | 6 | -2 | -1 |
| 15 | -7 | -3 | -6 | -2 | 1 |
| -15 | -7 | 2 | -1 | 2 | -1 |