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convert table to subsections

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this form is much easier to maintain (also with minimal diffs), and
allows for more details on each operator.

this change a purely mechanical transformation, without changing any contents.
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Valentin Gagarin 2022-12-22 21:21:26 +01:00
parent caebe4112e
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doc/manual/src/language/operators.md
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# Operators # Operators
The table below lists the operators in the Nix language, in ## Select
order of precedence (from strongest to weakest binding).
> *e* `.` *attrpath* \[ `or` *def* \]
Select attribute denoted by the attribute path *attrpath* from set *e*. (An attribute path is a dot-separated list of attribute names.) If the attribute doesn’t exist, return *def* if provided, otherwise abort evaluation.
Associativity: none
Precedence: 1
## Application
> *e1* *e2*
Call function *e1* with argument *e2*.
Associativity: left
Precedence: 2
## Arithmetic Negation
> `-` *e*
Arithmetic negation.
Associativity: none
Precedence: 3
## Has Attribute
> *e* `?` *attrpath*
Test whether set *e* contains the attribute denoted by *attrpath*; return `true` or `false`.
Associativity: none
Precedence: 4
## List Concatenation
> *e1* `++` *e2*
List concatenation.
Associativity: right
Precedence: 5
## Multiplication
> *e1* `*` *e2*,
Arithmetic multiplication.
Associativity: left
Precedence: 6
## Division
> *e1* `/` *e2*
Arithmetic division.
Associativity: left
Precedence: 6
## Addition
> *e1* `+` *e2*
Arithmetic addition.
Associativity: left
Precedence: 7
## Subtraction
> *e1* `-` *e2*
Arithmetic subtraction.
Associativity: left
Precedence: 7
## String Concatenation
> *string1* `+` *string2*
String concatenation.
Associativity: left
Precedence: 7
## Not
> `!` *e*
Boolean negation.
Associativity: none
Precedence: 8
## Update
> *e1* `//` *e2*
Return a set consisting of the attributes in *e1* and *e2* (with the latter taking precedence over the former in case of equally named attributes).
Associativity: right
Precedence: 9
## Less Than
> *e1* `<` *e2*,
Arithmetic/lexicographic comparison.
Associativity: none
Precedence: 10
## Less Than or Equal To
> *e1* `<=` *e2*
Arithmetic/lexicographic comparison.
Associativity: none
Precedence: 10
## Greater Than
> *e1* `>` *e2*
Arithmetic/lexicographic comparison.
Associativity: none
Precedence: 10
## Greater Than or Equal To
> *e1* `>=` *e2*
Arithmetic/lexicographic comparison.
Associativity: none
Precedence: 10
## Equality
> *e1* `==` *e2*
Equality.
Associativity: none
Precedence: 11
## Inequality
> *e1* `!=` *e2*
Inequality.
Associativity: none
Precedence: 11
## Logical AND
> *e1* `&&` *e2*
Logical AND.
Associativity: left
Precedence: 12
## Logical OR
> *e1* <code>&#124;&#124;</code> *e2*
Logical OR.
Associativity: left
Precedence: 13
## Logical Implication
> *e1* `->` *e2*
Logical implication (equivalent to <code>!e1 &#124;&#124; e2</code>).
Associativity: none
Precedence: 14
| Name | Syntax | Description | Associativity | Precedence |
| ------------------------ | ----------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------- | ---------- |
| Select | *e* `.` *attrpath* \[ `or` *def* \] | Select attribute denoted by the attribute path *attrpath* from set *e*. (An attribute path is a dot-separated list of attribute names.) If the attribute doesn’t exist, return *def* if provided, otherwise abort evaluation. | none | 1 |
| Application | *e1* *e2* | Call function *e1* with argument *e2*. | left | 2 |
| Arithmetic Negation | `-` *e* | Arithmetic negation. | none | 3 |
| Has Attribute | *e* `?` *attrpath* | Test whether set *e* contains the attribute denoted by *attrpath*; return `true` or `false`. | none | 4 |
| List Concatenation | *e1* `++` *e2* | List concatenation. | right | 5 |
| Multiplication | *e1* `*` *e2*, | Arithmetic multiplication. | left | 6 |
| Division | *e1* `/` *e2* | Arithmetic division. | left | 6 |
| Addition | *e1* `+` *e2* | Arithmetic addition. | left | 7 |
| Subtraction | *e1* `-` *e2* | Arithmetic subtraction. | left | 7 |
| String Concatenation | *string1* `+` *string2* | String concatenation. | left | 7 |
| Not | `!` *e* | Boolean negation. | none | 8 |
| Update | *e1* `//` *e2* | Return a set consisting of the attributes in *e1* and *e2* (with the latter taking precedence over the former in case of equally named attributes). | right | 9 |
| Less Than | *e1* `<` *e2*, | Arithmetic/lexicographic comparison. | none | 10 |
| Less Than or Equal To | *e1* `<=` *e2* | Arithmetic/lexicographic comparison. | none | 10 |
| Greater Than | *e1* `>` *e2* | Arithmetic/lexicographic comparison. | none | 10 |
| Greater Than or Equal To | *e1* `>=` *e2* | Arithmetic/lexicographic comparison. | none | 10 |
| Equality | *e1* `==` *e2* | Equality. | none | 11 |
| Inequality | *e1* `!=` *e2* | Inequality. | none | 11 |
| Logical AND | *e1* `&&` *e2* | Logical AND. | left | 12 |
| Logical OR | *e1* <code>&#124;&#124;</code> *e2* | Logical OR. | left | 13 |
| Logical Implication | *e1* `->` *e2* | Logical implication (equivalent to <code>!e1 &#124;&#124; e2</code>). | none | 14 |