Operators - Spicery/Nutmeg GitHub Wiki
Infix operators in Nutmeg are ordered by precedence, higher precedences binding tighter than lower values. The lowest precedence is 0.
| Operator | Precedence | Band | Description |
|---|---|---|---|
| x or y | 30 | B | Short-circuit boolean OR of x and y |
| x and y | 40 | B | Short-circuit boolean AND of x and y |
| x == y | 50 | C | Equality of x & y |
| x != y | 50 | C | Non-equality of x & y |
| x =^= y | 50 | C | Identity of x & y |
| x !^= y | 50 | C | Non-identity of x & y |
| a ..< b | 60 | R | Half-open range |
| a ... b | 60 | R | Closed range |
| x + y | 100 | A | Adds two numbers |
| x - y | 100 | A | Subtracts y from x |
| x * y | 200 | A | Multiplies x and y |
| x / y | 200 | A | Floating point division |
| x // y | 200 | A | Integer division c.f. x.div(y) |
| x ^ y | 300 | A | x to the power of y c.f. x.exp(y) |
| x ++ y | 500 | R | Append operator |
Bands
In addition, operators are grouped into bands and may only be compared if their bands overlap. If the bands do not overlap then the parser will require parentheses to force disambiguation.
| Band | Overlaps | Description |
|---|---|---|
| A | ACR | Arithmetic operator |
| B | BC | Boolean operator |
| C | ABC | Comparison operator |
| R | A | Range operator |
Another way of visualising the 'overlaps' relationship is shown below as a matrix.
| Band | A | B | C | R |
|---|---|---|---|---|
| A | x | x | x | |
| B | x | x | ||
| C | x | x | x | |
| R | x |
Notes
- Unlike many programming languages
notis not a prefix operator but a built-in function. - Bands syntactically enforce some rules that would emerge from type analysis. When Nutmeg has type checking, the parser is excused from flagging precedence violations that would be caught by the type checker.