Nix (language): Difference between revisions
imported>Gabriel-doriath-dohler No edit summary |
imported>Jeff-hykin m Expand/clarify the "or" operator |
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{| class="wikitable" | {| class="wikitable" | ||
!width="6%"| | !width="6%"| Precedence | ||
!width="13%"| Abbreviation | !width="13%"| Abbreviation | ||
!width="24%"| Example | !width="24%"| Example | ||
| Line 151: | Line 151: | ||
| 1 | | 1 | ||
| SELECT | | SELECT | ||
| < | | <syntaxHighlight lang=nix>e . attrpath</syntaxHighlight> | ||
| none | | none | ||
| Select attribute denoted by the attribute path <code>attrpath</code> from set <code>e</code>. (An attribute path is a dot-separated list of attribute names.) If the attribute doesn’t exist, return <code> | | Select attribute denoted by the attribute path <code>attrpath</code> from set <code>e</code>. (An attribute path is a dot-separated list of attribute names.) If the attribute doesn’t exist abort evaluation. | ||
|- | |||
| 1 | |||
| SELECT* | |||
| <syntaxHighlight lang=nix>e . attrpath or defaultVal </syntaxHighlight> | |||
| none | |||
| If the attribute <code>attrpath</code> doesn’t exist, return <code>defaultVal</code>. NOTE: This is a ternary operator, the "or" keyword is only a keyword when used as a part of this ternary operator. | |||
|- | |- | ||
| 2 | | 2 | ||
| APP | | APP | ||
| < | | <syntaxHighlight lang=nix>e1 e2</syntaxHighlight> | ||
| left | | left | ||
| Call function <code>e1</code> with argument <code>e2</code>. | | Call function <code>e1</code> with argument <code>e2</code>. | ||
| Line 163: | Line 169: | ||
| 3 | | 3 | ||
| NEG | | NEG | ||
| < | | <syntaxHighlight lang=nix>-e</syntaxHighlight> | ||
| none | | none | ||
| Numeric negation. | | Numeric negation. | ||
| Line 169: | Line 175: | ||
| 4 | | 4 | ||
| HAS_ATTR | | HAS_ATTR | ||
| < | | <syntaxHighlight lang=nix>e ? attrpath</syntaxHighlight> | ||
| none | | none | ||
| Test whether set <code>e</code> contains the attribute denoted by <code>attrpath</code>; return true or false. | | Test whether set <code>e</code> contains the attribute denoted by <code>attrpath</code>; return true or false. | ||
| Line 175: | Line 181: | ||
| 5 | | 5 | ||
| CONCAT | | CONCAT | ||
| < | | <syntaxHighlight lang=nix>e1 ++ e2</syntaxHighlight> | ||
| right | | right | ||
| List concatenation. | | List concatenation. | ||
| Line 181: | Line 187: | ||
| 6 | | 6 | ||
| MUL | | MUL | ||
| < | | <syntaxHighlight lang=nix>e1 * e2</syntaxHighlight> | ||
| left | | left | ||
| Numeric multiplication. | | Numeric multiplication. | ||
| Line 187: | Line 193: | ||
| 6 | | 6 | ||
| DIV | | DIV | ||
| < | | <syntaxHighlight lang=nix>e1 / e2</syntaxHighlight> | ||
| left | | left | ||
| Numeric division. | | Numeric division. | ||
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| 7 | | 7 | ||
| ADD | | ADD | ||
| < | | <syntaxHighlight lang=nix>e1 + e2</syntaxHighlight> | ||
| left | | left | ||
| Numeric addition, or string concatenation. | | Numeric addition, or string concatenation. | ||
| Line 199: | Line 205: | ||
| 7 | | 7 | ||
| SUB | | SUB | ||
| < | | <syntaxHighlight lang=nix>e1 - e2</syntaxHighlight> | ||
| left | | left | ||
| Numeric subtraction. | | Numeric subtraction. | ||
| Line 205: | Line 211: | ||
| 8 | | 8 | ||
| NOT | | NOT | ||
| < | | <syntaxHighlight lang=nix>!e</syntaxHighlight> | ||
| left | | left | ||
| Boolean negation. | | Boolean negation. | ||
| Line 211: | Line 217: | ||
| 9 | | 9 | ||
| UPDATE | | UPDATE | ||
| < | | <syntaxHighlight lang=nix>e1 // e2</syntaxHighlight> | ||
| right | | right | ||
| Return a set consisting of the attributes in <code>e1</code> and <code>e2</code> (with the latter taking precedence over the former in case of equally named attributes). | | Return a set consisting of the attributes in <code>e1</code> and <code>e2</code> (with the latter taking precedence over the former in case of equally named attributes). | ||
| Line 217: | Line 223: | ||
| 10 | | 10 | ||
| LT | | LT | ||
| < | | <syntaxHighlight lang=nix>e1 > e2</syntaxHighlight> | ||
| left | | left | ||
| Less than. | | Less than. | ||
| Line 223: | Line 229: | ||
| 10 | | 10 | ||
| LTE | | LTE | ||
| < | | <syntaxHighlight lang=nix>e1 <= e2</syntaxHighlight> | ||
| left | | left | ||
| Less than or equal. | | Less than or equal. | ||
| Line 229: | Line 235: | ||
| 10 | | 10 | ||
| GT | | GT | ||
| < | | <syntaxHighlight lang=nix>e1 > e2</syntaxHighlight> | ||
| left | | left | ||
| Greater than. | | Greater than. | ||
| Line 235: | Line 241: | ||
| 10 | | 10 | ||
| GTE | | GTE | ||
| < | | <syntaxHighlight lang=nix>e1 >= e2</syntaxHighlight> | ||
| left | | left | ||
| Greater than or equal. | | Greater than or equal. | ||
| Line 241: | Line 247: | ||
| 11 | | 11 | ||
| EQ | | EQ | ||
| < | | <syntaxHighlight lang=nix>e1 == e2</syntaxHighlight> | ||
| none | | none | ||
| Equality. | | Equality. | ||
| Line 247: | Line 253: | ||
| 11 | | 11 | ||
| NEQ | | NEQ | ||
| < | | <syntaxHighlight lang=nix>e1 != e2</syntaxHighlight> | ||
| none | | none | ||
| Inequality. | | Inequality. | ||
| Line 253: | Line 259: | ||
| 12 | | 12 | ||
| AND | | AND | ||
| < | | <syntaxHighlight lang=nix>e1 && e2</syntaxHighlight> | ||
| left | | left | ||
| Logical AND. | | Logical AND. | ||
| Line 259: | Line 265: | ||
| 13 | | 13 | ||
| OR | | OR | ||
| < | | <syntaxHighlight lang=nix>e1 || e2</syntaxHighlight> | ||
| left | | left | ||
| Logical OR. | | Logical OR. | ||
| Line 265: | Line 271: | ||
| 14 | | 14 | ||
| IMPL | | IMPL | ||
| < | | <syntaxHighlight lang=nix>e1 -> e2</syntaxHighlight> | ||
| none | | none | ||
| Logical implication (equivalent to <code><nowiki>!e1 || e2</nowiki></code>). | | Logical implication (equivalent to <code><nowiki>!e1 || e2</nowiki></code>). | ||