diff --git a/doc/functions.md b/doc/functions.md index 551ba522a9041..09033c9e3c199 100644 --- a/doc/functions.md +++ b/doc/functions.md @@ -8,5 +8,4 @@ functions/generators.section.md functions/debug.section.md functions/prefer-remote-fetch.section.md functions/nix-gitignore.section.md -functions/fileset.section.md ``` diff --git a/doc/functions/fileset.section.md b/doc/functions/fileset.section.md deleted file mode 100644 index c42337feaba4f..0000000000000 --- a/doc/functions/fileset.section.md +++ /dev/null @@ -1,48 +0,0 @@ - - -# File sets {#sec-fileset} - -The [`lib.fileset`](#sec-functions-library-fileset) library allows you to work with _file sets_. -A file set is a mathematical set of local files that can be added to the Nix store for use in Nix derivations. -File sets are easy and safe to use, providing obvious and composable semantics with good error messages to prevent mistakes. - -See the [function reference](#sec-functions-library-fileset) for function-specific documentation. - -## Implicit coercion from paths to file sets {#sec-fileset-path-coercion} - -All functions accepting file sets as arguments can also accept [paths](https://nixos.org/manual/nix/stable/language/values.html#type-path) as arguments. -Such path arguments are implicitly coerced to file sets containing all files under that path: -- A path to a file turns into a file set containing that single file. -- A path to a directory turns into a file set containing all files _recursively_ in that directory. - -If the path points to a non-existent location, an error is thrown. - -::: {.note} -Just like in Git, file sets cannot represent empty directories. -Because of this, a path to a directory that contains no files (recursively) will turn into a file set containing no files. -::: - -:::{.note} -File set coercion does _not_ add any of the files under the coerced paths to the store. -Only the [`toSource`](#function-library-lib.fileset.toSource) function adds files to the Nix store, and only those files contained in the `fileset` argument. -This is in contrast to using [paths in string interpolation](https://nixos.org/manual/nix/stable/language/values.html#type-path), which does add the entire referenced path to the store. -::: - -### Example {#sec-fileset-path-coercion-example} - -Assume we are in a local directory with a file hierarchy like this: -``` -├─ a/ -│ ├─ x (file) -│ └─ b/ -│   └─ y (file) -└─ c/ -   └─ d/ -``` - -Here's a listing of which files get included when different path expressions get coerced to file sets: -- `./.` as a file set contains both `a/x` and `a/b/y` (`c/` does not contain any files and is therefore omitted). -- `./a` as a file set contains both `a/x` and `a/b/y`. -- `./a/x` as a file set contains only `a/x`. -- `./a/b` as a file set contains only `a/b/y`. -- `./c` as a file set is empty, since neither `c` nor `c/d` contain any files. diff --git a/lib/fileset/default.nix b/lib/fileset/default.nix index 15af0813eec71..ea2475284ac69 100644 --- a/lib/fileset/default.nix +++ b/lib/fileset/default.nix @@ -1,3 +1,52 @@ +/* + + []{#sec-fileset} + + The [`lib.fileset`](#sec-functions-library-fileset) library allows you to work with _file sets_. + A file set is a mathematical set of local files that can be added to the Nix store for use in Nix derivations. + File sets are easy and safe to use, providing obvious and composable semantics with good error messages to prevent mistakes. + + See the [function reference](#sec-functions-library-fileset) for function-specific documentation. + + ## Implicit coercion from paths to file sets {#sec-fileset-path-coercion} + + All functions accepting file sets as arguments can also accept [paths](https://nixos.org/manual/nix/stable/language/values.html#type-path) as arguments. + Such path arguments are implicitly coerced to file sets containing all files under that path: + - A path to a file turns into a file set containing that single file. + - A path to a directory turns into a file set containing all files _recursively_ in that directory. + + If the path points to a non-existent location, an error is thrown. + + ::: {.note} + Just like in Git, file sets cannot represent empty directories. + Because of this, a path to a directory that contains no files (recursively) will turn into a file set containing no files. + ::: + + :::{.note} + File set coercion does _not_ add any of the files under the coerced paths to the store. + Only the [`toSource`](#function-library-lib.fileset.toSource) function adds files to the Nix store, and only those files contained in the `fileset` argument. + This is in contrast to using [paths in string interpolation](https://nixos.org/manual/nix/stable/language/values.html#type-path), which does add the entire referenced path to the store. + ::: + + ### Example {#sec-fileset-path-coercion-example} + + Assume we are in a local directory with a file hierarchy like this: + ``` + ├─ a/ + │ ├─ x (file) + │ └─ b/ + │   └─ y (file) + └─ c/ +   └─ d/ + ``` + + Here's a listing of which files get included when different path expressions get coerced to file sets: + - `./.` as a file set contains both `a/x` and `a/b/y` (`c/` does not contain any files and is therefore omitted). + - `./a` as a file set contains both `a/x` and `a/b/y`. + - `./a/x` as a file set contains only `a/x`. + - `./a/b` as a file set contains only `a/b/y`. + - `./c` as a file set is empty, since neither `c` nor `c/d` contain any files. +*/ { lib }: let