Elegant Code

Format for a simple grammar description language.

Syntax = Identifier {CRLF Rule}
Rule = {Identifier “=” Description}
Identifier = [Letter | Digit]
Description = {Node {” ” Node} }
Node = ZeroToMany|OneToMany|Symbol|TextString
TextString = “\”" [Letter|Digit] “\”"
ZeroToMany = “{” Node “}”
OneToMany = “[" Node "]”
Grouping = “(” Node “)”
UnknownContent = “…”
CRLF = <system dependent>

Example:

Javascript
Array_Literal = “[" {Expression {Expression ","} } "]”
Block = “{” {Statements} “}”
Break_Statement = “break” {Label_Name} “;”
Case_Clause = ["case" Expression ";"] Statements
Disruptive_Statement = [Break_Statement | Return_Statement | Throw_Statement]
Do_Statement = “do” Block “while” “(” Expression “)” “;”
Escaped_Character = “\” (”\” | “\’” | “\\” | “\/” | “b” | “f” | “n” | “r” | “t” | UnicodeChar)
UnicodeChar = “u” HexDigit HexDigit HexDigit HexDigit
Exponent = ["e" | "E"] {”+” | “-”} [Digit]
Expression = [Literal | Name | "(" Expression ")" | Prefix_Operator Expression | New_Expression | Delete_Expression | Complex_Expression]
Complex_Expression = Expression ( Infix_Operator Expression | “?” Expression “:” Expression | Invokation | Refinement )
New_Expression = “new” Expression Invokation
Delete_Expression = “delete” Expression Refinement
Expression = Name ({Refinement} Assignment_Operator | Additive_Operator | Subtractive_Operator ) | …
For_Statement = “for” “(” ( ( Name “in” Object ) | ( Initializtion_Statement “;” Condition_Statement “;” Increment_Statement ) ) Block
Fraction = “.” Digit
Function_Body = “{” Var_Statements Statements “}”
Function_Literal = “function” ( Name | “” ) Function_Params Function_Body
If_Statement = “if” “(” Expression “)” Then_Block {”else” ( If_Statement | Block )}
Infix_Operator = Multiply | Divide | Modulo | Add | Subtract | GreaterOrEqual | LessOrEqual | Greater | Less | EqualTo | NotEqualTo | LogicalOr | LogicalAnd
Multiply = “*”
NonZeroDigit = “1″ | “2″ | “3″ | “4″ | “5″ | “6″ | “7″ | “8″ | “9″
Digit = “0″ | NonZeroDigit
Integer = “0″ | ( NonZeroDigit {Digit} )
Invocation = “(” Expression { “,” Expression } “)”
Literal = Number_Literal | String_Literal | Object_Literal | Array_Literal | Function_Literal | RegExp_Literal
Name = [ Letter | Digit | "_" ]
Number_Literal = Integer {Fraction} {Exponent}
Object_Literal = “{” { Field_Assignment {Field_Assignment “,” } } “}”
Function_Parameters = “(” Name { “,” Name } “)”
Prefix_Operator = “typeof”| “+” | “-” | “!”
Refinement = “.” Name | “[" Expression "]”
Return_Stmt = “return” ( Expression | “” ) “;”
Statements = { {StatementLabel “:”} Expression_Statement “;” | Disruptive_Stmt | Try_Stmt | If_Stmt | Switch_Stmt | While_Stmt | For_Stmt | Do_Stmt }
String_Literal = …
Switch_Statement = “switch” “(” Expression “)” “{” Switch_Body “}”
Switch_Body = Case_Clause { Disruptive_Stmt (Switch_Body | Switch_Default) } “}”
Switch_Default = “default” “:” Statements
Throw_Stmt = “throw” Expression “;”
Try_Stmt = “try” Block “catch” “(” Variable_Name “)” Block
Var_Assignment = “Name” “=” Expression
Var_Stmt = “var” (Name | Var_Assignment) {”,” Var_Assignment} “;”
While_Stmt = “while” “(” Expression “)” Block
Whitespace = ” ” | “\t” | CRLF | Comments
Comments = ( “\\” NonLineEndChars CRLF ) | ( “\*” … “*/”)

Technorati : Javascript
Del.icio.us : Javascript
Zooomr : Javascript
Flickr : Javascript