= Import

The built-in `import` function provides a way to parse a `.nix` file.

[source,nix]
.a.nix
....
{
  message = "You successfully imported me!";
  b = 12;
}
....

[source]
.Example
....
nix-repl> a = import ./a.nix

nix-repl> a.message
"You successfully imported me!"

nix-repl> a.b
12
....

[NOTE]
====
If path supplied to the `import` function is a directory,
the file default.nix in that directory is imported.
====

The scope of the imported file does not inherit the scope of the importer.

[source,nix]
.b.nix
....
x + 7
....

[source]
.Example
....
nix-repl> x = 12

nix-repl> y = import ./b.nix

nix-repl> y
error:
       … while calling the 'import' builtin
         at «string»:1:2:
            1|  import ./b.nix
             |  ^

       error: undefined variable 'x'
       at /home/amy/codeberg/nix-book/b.nix:1:1:
            1| x + 7
             | ^
            2|
....

So to pass information when importing something, use a function.

[source,nix]
.c.nix
....
x: x + 7
....

[source]
.Example
....
nix-repl> f = import ./c.nix

nix-repl> f 12
19
....

The imported file may import other files, which may in turn import more files.