.. _syntax_overview:

Syntax Overview
===============

This is a cheatsheet for Roto's syntax. Refer to the :doc:`language_reference` for the
full explanation of these concepts.

+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
|           Name           |                         Example                         |                           See                            |
+==========================+=========================================================+==========================================================+
| Comment                  | ``# this is a comment``                                 | :ref:`lang_comments`                                     |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Unit                     | ``()``                                                  | :ref:`lang_unit`                                         |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Never type               | ``!``                                                   | :ref:`lang_never`                                        |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Boolean                  | ``true``, ``false``                                     | :ref:`lang_booleans`, :roto:ref:`bool`                   |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Integer                  | ``10``, ``-100``, ``0``                                 | :ref:`lang_integers`                                     |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Float                    | ``10.5``, ``-10.0``, ``1.``, ``1e+10``                  | :ref:`lang_floats`                                       |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| IP address               | ``0.0.0.0``, ``2001:DB8::5673:23b5``, ``::``            | :roto:ref:`IpAddr`                                       |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| AS number                | ``AS1234``                                              | :roto:ref:`Asn`                                          |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| String                   | ``"hello, world!"``                                     | :ref:`lang_strings`, :roto:ref:`String`                  |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Format string            | ``f"hello, world!"``                                    | :ref:`lang_string_formatting`                            |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Optional values          | ``None``, ``Some(x)``                                   | :ref:`lang_optionals`                                    |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Anonymous record         | ``{ x: 10, y: 20 }``                                    | :ref:`lang_anonymous_records`                            |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Named record             | ``Foo { x: 10, y: 20 }``                                | :ref:`lang_named_records`                                |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| List                     | ``[10, 20, 30]``                                        | :ref:`lang_lists`, :roto:ref:`List[T]`                   |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Unary operator           | ``-x``                                                  | :ref:`lang_arithmetic`                                   |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Binary operator          | ``x + y``                                               | :ref:`lang_arithmetic`                                   |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Assignment               | ``x = 10``                                              | :ref:`lang_locals`                                       |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Field access             | ``x.y``                                                 | :ref:`lang_anonymous_records`, :ref:`lang_named_records` |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Function call            | ``add(x, y)``                                           |                                                          |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Method call              | ``x.add(y)``                                            |                                                          |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Static method call       | ``String.append(x, y)``                                 |                                                          |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Let binding              | ``let x = 10``                                          | :ref:`lang_locals`                                       |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Function declaration     | ``fn add(x: i32, y: i32) -> i32 { .. }``                | :ref:`lang_functions`                                    |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Filter-map declaration   | ``filter foo(..) { .. }``, ``filtermap foo(..) { .. }`` | :ref:`lang_filtermap`                                    |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Record declaration       | ``record Foo { .. }``                                   | :ref:`lang_named_records`                                |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Enum declaration         | ``enum Foo { .. }``                                     | :ref:`lang_enum_type`                                    |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| If-else                  | ``if x == 1 { .. }``, ``if x == 1 {..} else {..}``      | :ref:`lang_if_else`                                      |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Pattern matching         | ``match x { .. }``                                      | :ref:`lang_match`                                        |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| While loop               | ``while x < 10 { .. }``                                 | :ref:`lang_while`                                        |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| For loop                 | ``for x in e { .. }``                                   | :ref:`lang_for`                                          |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Return                   | ``return x``                                            | :ref:`lang_functions`                                    |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Verdict                  | ``accept x``, ``reject x``                              | :ref:`lang_filtermap`                                    |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+
| Import items from module | ``import foo.bar``                                      | :ref:`lang_imports`                                      |
+--------------------------+---------------------------------------------------------+----------------------------------------------------------+