Nix (language): Difference between revisions

Line 52:

| Integers || There is no float in the nix language|| <code>5</code>

|-

| Path || relative paths will become to absolute when evaluated,paths must contain a slash || <~~code~~>./hello/world</~~code~~>

| Path || relative paths will become to absolute when evaluated,paths must contain a slash. <code><nixpkgs/pkgs></code> is also possible and will resolve to the folder incl. subfolders in your NIX_PATH || <syntaxHighlight>./hello/world

> /abs/path/to/hello/world

</syntaxHighlight>

> /path/to/your/nixpkgs/lib</syntaxHighlight>

|-

| URI || || <code>http://example.org/foo.tar.bz2</code>

Line 60:

Line 64:

| Null || || <code>null</code>

|-

| Lists || items are not separated by comma, can contain any other type || <syntaxHighlight lang=nix>[ 1 ./example.bin { hello="world"; }] </syntaxHighlight>

|-

| Sets || In other languages called <code>dicts</code>(py),<code>objects</code>(js) <code>hashes</code>(ruby), essentially a list of key-value pairs || <syntaxHighlight lang=nix>{ hello="world"; }.hello

> "world"</syntaxHighlight>

|-

| Functions || see below || <code>pattern: body</code>

|}

A detailed description of all types can be found in [https://nixos.org/nix/manual/#ssec-values The Nix manual]

=== functions ===

Functions have the following form: <code>pattern: body</code>

There are 3 patterns in how functions can be written:

~~TODO~~

# <code>f = a: a*a;</code> a single identifier, can be extended with multiple identifiers as <code>f = a: b: a*b;</code> as a partial function would be returned.

# <code>{ x, y ? "foo", z ? "bar", ... }: z + y + x</code> a set pattern, which can also set defaults. ellipse means that the function may receive extra arguments.

# <code>args@{ x, y, z, ... }: z + y + x + args.a</code> an <code>@</code> pattern which can be used to match extra arguments and store them in the <code>args</code> set.

=== imports ===

~~TODO~~

<code>import</code> loads, parses and imports the nix expression stored in path. This keyword is essentially a builtin of nix but not a part of the language itself.

Usage:

x = import <nixpkgs> {};

y = trace x.pkgs.hello.name x;

</syntaxHighlight>

=== notable constructs ===

@@ Line 52: / Line 52: @@
 | Integers || There is no float in the nix language|| <code>5</code>
 |-
-| Path || relative paths will become to absolute when evaluated,paths must contain a slash || <code>./hello/world</code>
+| Path || relative paths will become to absolute when evaluated,paths must contain a slash. <code><nixpkgs/pkgs></code> is also possible and will resolve to the folder incl. subfolders in your NIX_PATH || <syntaxHighlight>./hello/world
+> /abs/path/to/hello/world
+</syntaxHighlight>
+<syntaxHighlight><nixpkgs/lib>
+> /path/to/your/nixpkgs/lib</syntaxHighlight>
 |-
 | URI ||  || <code>http://example.org/foo.tar.bz2</code>
@@ Line 60: / Line 64: @@
 | Null ||  || <code>null</code>
 |-
+| Lists || items are not separated by comma, can contain any other type || <syntaxHighlight lang=nix>[ 1 ./example.bin { hello="world"; }] </syntaxHighlight>
+|-
+| Sets || In other languages called <code>dicts</code>(py),<code>objects</code>(js) <code>hashes</code>(ruby), essentially a list of key-value pairs || <syntaxHighlight lang=nix>{ hello="world"; }.hello
+> "world"</syntaxHighlight>
+|-
+| Functions || see below || <code>pattern: body</code>
 |}
 A detailed description of all types can be found in [https://nixos.org/nix/manual/#ssec-values The Nix manual]
 === functions ===
+Functions have the following form: <code>pattern: body</code>
+There are 3 patterns in how functions can be written:
-TODO
+# <code>f = a: a*a;</code> a single identifier, can be extended with multiple identifiers as <code>f = a: b: a*b;</code> as a partial function would be returned.
+# <code>{ x, y ? "foo", z ? "bar", ... }: z + y + x</code> a set pattern, which can also set defaults. ellipse means that the function may receive extra arguments.
+# <code>args@{ x, y, z, ... }: z + y + x + args.a</code> an <code>@</code> pattern which can be used to match extra arguments and store them in the <code>args</code> set.
 === imports ===
-TODO
+<code>import</code> loads, parses and imports the nix expression stored in path. This keyword is essentially a builtin of nix but not a part of the language itself.
+Usage:
+<syntaxHighlight lang=nix>
+  x = import <nixpkgs> {};
+  y = trace x.pkgs.hello.name x;
+</syntaxHighlight>
 === notable constructs ===