zig/README.md

zig lang

An experiment in writing a low-level programming language with the intent to replace C. Zig intends to be a small language, yet powerful enough to write readable, safe, optimal, and concise code to solve any computing problem.

Goals

• Ability to run arbitrary code at compile time and generate code.
• Completely compatible with C libraries with no wrapper necessary.
• Creating a C library should be a primary use case. Should be easy to export an auto-generated .h file.
• Generics such as containers.
• Do not depend on libc unless explicitly imported.
• First class error code support.
• Include documentation generator.
• Eliminate the need for make, cmake, etc.
• Friendly toward package maintainers.
• Eliminate the need for C headers (when using zig internally).
• Ability to declare dependencies as Git URLS with commit locking (can provide a tag or sha1).
• Tagged union enum type.
• Opinionated when it makes life easier.
  • Tab character in source code is a compile error.
  • Whitespace at the end of line is a compile error.
• Resilient to parsing errors to make IDE integration work well.
• Source code is UTF-8.
• Shebang line OK so language can be used for "scripting" as well.
• Ability to mark functions as test and automatically run them in test mode.
• Memory zeroed by default, unless you initialize with "uninitialized".

Roadmap

• Unit tests.
• C style comments.
• Simple .so library
• Multiple files
• figure out integers
• inline assembly and syscalls
• running code at compile time
• implement a simple game using SDL2
• How should the Widget use case be solved? In Genesis I'm using C++ and inheritance.

Primitive Numeric Types:

zig	C equivalent	Description
i8	int8_t	signed 8-bit integer
u8	uint8_t	unsigned 8-bit integer
i16	int16_t	signed 16-bit integer
u16	uint16_t	unsigned 16-bit integer
i32	int32_t	signed 32-bit integer
u32	uint32_t	unsigned 32-bit integer
i64	int64_t	signed 64-bit integer
u64	uint64_t	unsigned 64-bit integer
f32	float	32-bit IEE754 floating point
f64	double	64-bit IEE754 floating point
f128	long double	128-bit IEE754 floating point
isize	ssize_t	signed pointer sized integer
usize	size_t	unsigned pointer sized integer

Grammar

Root : many(TopLevelDecl) token(EOF)

TopLevelDecl : FnDef | ExternBlock

ExternBlock : many(Directive) token(Extern) token(LBrace) many(FnProtoDecl) token(RBrace)

FnProto : token(Fn) token(Symbol) ParamDeclList option(token(Arrow) Type)

FnDecl : FnProto token(Semicolon)

FnDef : many(Directive) FnProto Block

ParamDeclList : token(LParen) list(ParamDecl, token(Comma)) token(RParen)

ParamDecl : token(Symbol) token(Colon) Type

Type : token(Symbol) | PointerType | token(Unreachable)

PointerType : token(Star) token(Const) Type  | token(Star) token(Mut) Type

Block : token(LBrace) many(Statement) token(RBrace)

Statement : ExpressionStatement  | ReturnStatement

ExpressionStatement : Expression token(Semicolon)

ReturnStatement : token(Return) Expression token(Semicolon)

Expression : token(Number) | token(String) | token(Unreachable) | FnCall

FnCall : token(Symbol) token(LParen) list(Expression, token(Comma)) token(RParen)

Directive : token(NumberSign) token(Symbol) token(LParen) token(String) token(RParen)