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Diffstat (limited to 'doc/manual/src/language/builtin-constants.md')
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diff --git a/doc/manual/src/language/builtin-constants.md b/doc/manual/src/language/builtin-constants.md deleted file mode 100644 index 99520ad3f..000000000 --- a/doc/manual/src/language/builtin-constants.md +++ /dev/null @@ -1,44 +0,0 @@ -# Built-in Constants - -These constants are built into the Nix language evaluator: - -- [`builtins`]{#builtins-builtins} (attribute set) - - Contains all the [built-in functions](./builtins.md) and values. - - Since built-in functions were added over time, [testing for attributes](./operators.md#has-attribute) in `builtins` can be used for graceful fallback on older Nix installations: - - ```nix - # if hasContext is not available, we assume `s` has a context - if builtins ? hasContext then builtins.hasContext s else true - ``` - -- [`builtins.currentSystem`]{#builtins-currentSystem} (string) - - The built-in value `currentSystem` evaluates to the Nix platform - identifier for the Nix installation on which the expression is being - evaluated, such as `"i686-linux"` or `"x86_64-darwin"`. - - Not available in [pure evaluation mode](@docroot@/command-ref/conf-file.md#conf-pure-eval). - -- [`builtins.currentTime`]{#builtins-currentTime} (integer) - - Return the [Unix time](https://en.wikipedia.org/wiki/Unix_time) at first evaluation. - Repeated references to that name will re-use the initially obtained value. - - Example: - - ```console - $ nix repl - Welcome to Nix 2.15.1 Type :? for help. - - nix-repl> builtins.currentTime - 1683705525 - - nix-repl> builtins.currentTime - 1683705525 - ``` - - The [store path](@docroot@/glossary.md#gloss-store-path) of a derivation depending on `currentTime` will differ for each evaluation. - - Not available in [pure evaluation mode](@docroot@/command-ref/conf-file.md#conf-pure-eval). |