mirror of
https://github.com/ziglang/zig.git
synced 2024-11-28 08:02:32 +00:00
208 lines
7.3 KiB
Markdown
208 lines
7.3 KiB
Markdown
# Language Reference
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## Primitive Numeric Types:
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zig | C equivalent | Description
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-------------|------------------------|-------------------------------
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bool | bool | unsigned 1-bit integer
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i8 | int8_t | signed 8-bit integer
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u8 | uint8_t | unsigned 8-bit integer
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i16 | int16_t | signed 16-bit integer
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u16 | uint16_t | unsigned 16-bit integer
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i32 | int32_t | signed 32-bit integer
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u32 | uint32_t | unsigned 32-bit integer
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i64 | int64_t | signed 64-bit integer
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u64 | uint64_t | unsigned 64-bit integer
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f32 | float | 32-bit IEE754 floating point
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f64 | double | 64-bit IEE754 floating point
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f128 | long double | 128-bit IEE754 floating point
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isize | intptr_t | signed pointer sized integer
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usize | uintptr_t | unsigned pointer sized integer
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c_short | short | for API compatibility with C
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c_ushort | unsigned short | for API compatibility with C
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c_int | int | for API compatibility with C
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c_uint | unsigned int | for API compatibility with C
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c_long | long | for API compatibility with C
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c_ulong | unsigned long | for API compatibility with C
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c_longlong | long long | for API compatibility with C
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c_ulonglong | unsigned long long | for API compatibility with C
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## Grammar
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```
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Root : many(TopLevelDecl) token(EOF)
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TopLevelDecl : FnDef | ExternBlock | RootExportDecl | Use | StructDecl
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StructDecl : many(Directive) token(Struct) token(Symbol) token(LBrace) many(StructField) token(RBrace)
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StructField : token(Symbol) token(Colon) Type token(Comma)
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Use : many(Directive) token(Use) token(String) token(Semicolon)
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RootExportDecl : many(Directive) token(Export) token(Symbol) token(String) token(Semicolon)
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ExternBlock : many(Directive) token(Extern) token(LBrace) many(FnDecl) token(RBrace)
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FnProto : many(Directive) option(FnVisibleMod) token(Fn) token(Symbol) ParamDeclList option(token(Arrow) Type)
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Directive : token(NumberSign) token(Symbol) token(LParen) token(String) token(RParen)
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FnVisibleMod : token(Pub) | token(Export)
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FnDecl : FnProto token(Semicolon)
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FnDef : FnProto Block
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ParamDeclList : token(LParen) list(ParamDecl, token(Comma)) token(RParen)
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ParamDecl : token(Symbol) token(Colon) Type | token(Ellipsis)
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Type : token(Symbol) | token(Unreachable) | token(Void) | PointerType | ArrayType
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PointerType : token(Star) (token(Const) | token(Mut)) Type
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ArrayType : token(LBracket) Type token(Semicolon) Expression token(RBracket)
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Block : token(LBrace) list(option(Statement), token(Semicolon)) token(RBrace)
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Statement : Label | VariableDeclaration token(Semicolon) | NonBlockExpression token(Semicolon) | BlockExpression
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Label: token(Symbol) token(Colon)
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VariableDeclaration : token(Let) option(token(Mut)) token(Symbol) (token(Eq) Expression | token(Colon) Type option(token(Eq) Expression))
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Expression : BlockExpression | NonBlockExpression
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NonBlockExpression : ReturnExpression | AssignmentExpression | AsmExpression
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AsmExpression : token(Asm) option(token(Volatile)) token(LParen) token(String) option(AsmOutput) token(RParen)
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AsmOutput : token(Colon) list(AsmOutputItem, token(Comma)) option(AsmInput)
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AsmInput : token(Colon) list(AsmInputItem, token(Comma)) option(AsmClobbers)
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AsmOutputItem : token(LBracket) token(Symbol) token(RBracket) token(String) token(LParen) token(Symbol) token(RParen)
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AsmInputItem : token(LBracket) token(Symbol) token(RBracket) token(String) token(LParen) Expression token(RParen)
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AsmClobbers: token(Colon) list(token(String), token(Comma))
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AssignmentExpression : BoolOrExpression token(Equal) BoolOrExpression | BoolOrExpression
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BlockExpression : IfExpression | Block
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BoolOrExpression : BoolAndExpression token(BoolOr) BoolOrExpression | BoolAndExpression
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ReturnExpression : token(Return) option(Expression)
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IfExpression : token(If) Expression Block option(Else | ElseIf)
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ElseIf : token(Else) IfExpression
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Else : token(Else) Block
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BoolAndExpression : ComparisonExpression token(BoolAnd) BoolAndExpression | ComparisonExpression
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ComparisonExpression : BinaryOrExpression ComparisonOperator BinaryOrExpression | BinaryOrExpression
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ComparisonOperator : token(BoolEq) | token(BoolNotEq) | token(BoolLessThan) | token(BoolGreaterThan) | token(BoolLessEqual) | token(BoolGreaterEqual)
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BinaryOrExpression : BinaryXorExpression token(BinOr) BinaryOrExpression | BinaryXorExpression
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BinaryXorExpression : BinaryAndExpression token(BinXor) BinaryXorExpression | BinaryAndExpression
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BinaryAndExpression : BitShiftExpression token(BinAnd) BinaryAndExpression | BitShiftExpression
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BitShiftExpression : AdditionExpression BitShiftOperator BitShiftExpression | AdditionExpression
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BitShiftOperator : token(BitShiftLeft) | token(BitShiftRight)
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AdditionExpression : MultiplyExpression AdditionOperator AdditionExpression | MultiplyExpression
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AdditionOperator : token(Plus) | token(Minus)
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MultiplyExpression : CastExpression MultiplyOperator MultiplyExpression | CastExpression
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MultiplyOperator : token(Star) | token(Slash) | token(Percent)
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CastExpression : CastExpression token(as) Type | PrefixOpExpression
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PrefixOpExpression : PrefixOp PrefixOpExpression | SuffixOpExpression
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SuffixOpExpression : PrimaryExpression option(FnCallExpression | ArrayAccessExpression | FieldAccessExpression)
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FieldAccessExpression : token(Dot) token(Symbol)
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FnCallExpression : token(LParen) list(Expression, token(Comma)) token(RParen)
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ArrayAccessExpression : token(LBracket) Expression token(RBracket)
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PrefixOp : token(Not) | token(Dash) | token(Tilde)
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PrimaryExpression : token(Number) | token(String) | KeywordLiteral | GroupedExpression | token(Symbol) | Goto | BlockExpression
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Goto: token(Goto) token(Symbol)
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GroupedExpression : token(LParen) Expression token(RParen)
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KeywordLiteral : token(Unreachable) | token(Void) | token(True) | token(False)
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```
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## Operator Precedence
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```
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x() x[] x.y
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!x -x ~x
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as
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* / %
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+ -
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<< >>
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&
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^
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== != < > <= >=
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&&
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= += -=
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```
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## Literals
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### Characters and Strings
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| Example | Characters | Escapes | Null Term | Type
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---------------------------------------------------------------------------------
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Byte | 'H' | All ASCII | Byte | No | u8
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UTF-8 Bytes | "hello" | All Unicode | Byte & Unicode | No | [5; u8]
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UTF-8 C string | c"hello" | All Unicode | Byte & Unicode | Yes | *const u8
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### Byte Escapes
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| Name
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-----------------------------------------------
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\x7F | 8-bit character code (exactly 2 digits)
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\n | Newline
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\r | Carriage return
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\t | Tab
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\\ | Backslash
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\0 | Null
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\' | Single quote
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\" | Double quote
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### Unicode Escapes
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| Name
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----------------------------------------------------------
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\u{7FFF} | 24-bit Unicode character code (up to 6 digits)
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### Numbers
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Number literals | Example | Exponentiation
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-------------------------------------------
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Decimal integer | 98222 | N/A
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Hex integer | 0xff | N/A
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Octal integer | 0o77 | N/A
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Binary integer | 0b11110000 | N/A
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Floating-point | 123.0E+77 | Optional
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