Language design

Table of contents

Introduction

This document is provisional

Tour of the basics

Code and comments

Build modes

Types are values

Values usable as types

Primitive types

`bool`

Integer types

Integer literals

Floating-point types

Floating-point literals

String types

String literals

Values, objects, and expressions

Expression categories

Expression phases

Composite types

Tuples

Struct types

Pointer types

Arrays and buffers

Slices

Expressions

Declarations, Definitions, and Scopes

Patterns

Binding patterns

Destructuring patterns

Refutable patterns

Name-binding declarations

Constant `let` declarations

Variable `var` declarations

`auto`

Global constants and variables

Functions

Parameters

`auto` return type

Blocks and statements

Control flow

`if` and `else`

Loops

`while`

`for`

`break`

`continue`

`return`

`returned var`

`match`

User-defined types

Classes

Assignment

Non-instance member functions

Methods

Inheritance

Access control

Destructors

`const`

Unformed state

Move

Mixins

Choice types

Names

Files, libraries, packages

Package declaration

Imports

Same-package imports

Cross-package imports

Name visibility

Package scope

Namespaces

Naming conventions

Aliases

Name lookup

Name lookup for common types

Generics

Checked and template parameters

Interfaces and implementations

Combining constraints

Template name lookup

Associated constants

Generic entities

Generic Classes

Generic choice types

Generic interfaces

Generic implementations

Other features

Generic type equality and `observe` declarations

Operator overloading

Common type

Bidirectional interoperability with C and C++

Goals

Non-goals

Importing and `#include`

ABI and dynamic linking

Operator overloading

Templates

Standard types

Inheritance

Enums

Unfinished tales

Safety

Lifetime and move semantics

Metaprogramming

Pattern matching as function overload resolution

Error handling

Execution abstractions

Abstract machine and execution model

Lambdas

Co-routines

Concurrency