Operators
Operators perform operations on variables and return a result.
Pollen has the standard set of arithmetic and logical operators (shared with C) and adds a few assignment operators of its own.
| Category | Operators |
|---|---|
| Arithemetic | + - * / % |
| Relational | > >= < <= == != && || |
| Increment and Decrement | ++ -- |
| Bitwise | & | ^ |
| Assignment | = += -= *= /= %= &= ^= |= <<= >>= := @= |
| Ternary | ? : |
Binding Operator
The first Pollen specific assignment operator is :=. It is used to bind a
protocol member to a module which implements the protocol. It is called the
binding operator.
(More information on the binding operator found
here.)
GlobalInterruptsProtocol GI := Mcu.GlobalInterrupts // bind a protocol member
Pegging Operator
The second unique Pollen assignment operator is @= and this is used to
peg class references to byte arrays. This allows allocating a target
class object by overlaying its definition onto an index of a byte
array. The byte array at that index must contain a valid instance of
the class object. It is called the pegging operator.
(More information on the pegging operator found
here.)
Class1 cref @= array1 // peg object to array
Operator Precedence
Pollen has the same operator precedence as C. Here is a table of operator precedence. Operators with higher precedence are evaluated before operators with relatively lower precedence. Operators on the same line have equal precedence. When operators of equal precedence appear in the same expression, a rule must govern which is evaluated first. All binary operators except for the assignment operators are evaluated from left to right; assignment operators are evaluated right to left.
| Operators | Precedence |
|---|---|
| Postfix | expr++ expr-- |
| Unary | ++expr --expr +expr -expr ~ ! |
| Multiplicative | * / % |
| Additive | + - |
| Bit shift | << >>
|
| Relational | < > <= >= |
| Equality | == != |
| Bitwise AND | & |
| Bitwise exclusive OR | ^ |
| Bitwise inclusive OR | | |
| Logical AND | && |
| Logical OR | || |
| Ternary | ? : |
| Assignment | = += -= *= /= %= &= ^= |= <<= >>= @= := |