Ada Programming/Operators

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Standard operators

Ada allows operator overloading for all standard operators and so the following summaries can only describe the suggested standard operations for each operator. It is quite possible to misuse any standard operator to perform something unusual.

Each operator is either a keyword or a delimiter -- hence all operator pages are redirects to the appropriate keyword or delimiter.

Operators have arguments which in the RM are called Left and Right for binary operators, Right for unary operators (indicating the position with respect to the operator symbol).

The list is sorted from lowest precedence to highest precedence.

Logical operators

and: and $x \land y$ , (also keyword and)
or: or $x \lor y$ , (also keyword or)
xor: exclusive or $(x \land \bar{y}) \lor (\bar{x} \land y)$ , (also keyword xor)

Relational operators

/=: Not Equal $x \ne y$ , (also special character /=)
=: Equal $x = y$ , (also special character =)
<: Less than $x<y$ , (also special character <)
<=: Less than or equal to ( $x \le y$ ), (also special character <=)
>: Greater than ( $x > y$ ), (also special character >)
>=: Greater than or equal to ( $x \ge y$ ), (also special character >=)

Binary adding operators

+: Add $x + y$ , (also special character +)
-: Subtract $x - y$ , (also special character -)
&: Concatenate , $x$ & $y$ , (also special character &)

Unary adding operators

+: Plus sign $+x$ , (also special character +)
-: Minus sign $-x$ , (also special character -)

Multiplying operator

*: Multiply, $x \times y$ , (also special character *)
/: Divide $x / y$ , (also special character /)
mod: modulus (also keyword mod)
rem: remainder (also keyword rem)

Highest precedence operator

**: Power $x^y$ , (also special character **)
not: logical not $\lnot x$ , (also keyword not)
abs: absolute value $|x|$ (also keyword abs)

Short-circuit control forms

These are not operators and thus cannot be overloaded.

and then: e.g. if Y /= 0 and then X/Y > Limit then ...
or else: e.g. if Ptr = null or else Ptr.I = 0 then ...

Membership tests

The Membership Tests also cannot be overloaded because they are not operators.

in: element of, $var \in type$ , e.g. if I in Positive then, (also keyword in)
not in: not element of, $var \notin type$ , e.g. if I not in Positive then, (also keywords not in)

Range membership test

if Today not in Tuesday .. Thursday then
   ...

Subtype membership test

Is_Non_Negative := X in Natural;

Class membership test

exit when Object in Circle'Class;