# Operators
| Name | Syntax | Associativity | Precedence |
|----------------------------------------|--------------------------------------------|---------------|------------|
| [Attribute selection] | *attrset* `.` *attrpath* \[ `or` *expr* \] | none | 1 |
| [Function application] | *func* *expr* | left | 2 |
| [Arithmetic negation][arithmetic] | `-` *number* | none | 3 |
| [Has attribute] | *attrset* `?` *attrpath* | none | 4 |
| List concatenation | *list* `++` *list* | right | 5 |
| [Multiplication][arithmetic] | *number* `*` *number* | left | 6 |
| [Division][arithmetic] | *number* `/` *number* | left | 6 |
| [Subtraction][arithmetic] | *number* `-` *number* | left | 7 |
| [Addition][arithmetic] | *number* `+` *number* | left | 7 |
| [String concatenation] | *string* `+` *string* | left | 7 |
| [Path concatenation] | *path* `+` *path* | left | 7 |
| [Path and string concatenation] | *path* `+` *string* | left | 7 |
| [String and path concatenation] | *string* `+` *path* | left | 7 |
| Logical negation (`NOT`) | `!` *bool* | none | 8 |
| [Update] | *attrset* `//` *attrset* | right | 9 |
| [Less than][Comparison] | *expr* `<` *expr* | none | 10 |
| [Less than or equal to][Comparison] | *expr* `<=` *expr* | none | 10 |
| [Greater than][Comparison] | *expr* `>` *expr* | none | 10 |
| [Greater than or equal to][Comparison] | *expr* `>=` *expr* | none | 10 |
| [Equality] | *expr* `==` *expr* | none | 11 |
| Inequality | *expr* `!=` *expr* | none | 11 |
| Logical conjunction (`AND`) | *bool* `&&` *bool* | left | 12 |
| Logical disjunction (`OR`) | *bool* <code>\|\|</code> *bool* | left | 13 |
| [Logical implication] | *bool* `->` *bool* | right | 14 |
| [Pipe operator] (experimental) | *expr* `\|>` *func* | left | 15 |
| [Pipe operator] (experimental) | *func* `<\|` *expr* | right | 15 |
<!-- TODO(@rhendric, #10970): ^ rationalize number -> int/float -->
## Attribute selection
> **Syntax**
>
> *attrset* `.` *attrpath* \[ `or` *expr* \]
Select the attribute denoted by attribute path *attrpath* from [attribute set] *attrset*.
If the attribute doesn’t exist, return the *expr* after `or` if provided, otherwise abort evaluation.
## Function application
> **Syntax**
>
> *func* *expr*
Apply the callable value *func* to the argument *expr*. Note the absence of any visible operator symbol.
A callable value is either:
- a [user-defined function][function]
- a [built-in][builtins] function
- an attribute set with a [`__functor` attribute](./syntax.md#attr-__functor)