Syntax of DelphiWebScript II in EBNF

 

The description of the syntax uses the EBNF ("Enhanced Backus Naur Form").

 

 

Syntax

 

The start non-terminal is SCRIPT

 

SCRIPT =

[ ROOTSTATEMENT { ";" ROOTSTATEMENT } [ ";" ] ]

 

ROOTSTATEMENT =

TYPEDECL |

PROCDECL |

STATEMENT

 

STATEMENT =

VARDECL |

CONSTDECL |

BLOCK

 

VARDECL =

"var" NAME ":" TYPEDEF [ "=" EXPR ]

 

TYPEDECL =

"type" NAME "=" TYPEDEF

 

TYPEDEF =

"Boolean" | "Integer" | "Float" | "String" | "DateTime" | "Variant"

NAME |

ENUMDEF |

ARRAYDEF |

RECORDDEF |

CLASSDEF

 

ENUMDEF =

"(" NAME [ "=" EXPR ] { "," NAME [ "=" EXPR ] } ")"

 

ARRAYDEF =

"array" "[" EXPR ".." EXPR {"," EXPR ".." EXPR} "]" "of" TYPEDEF |

"array" "of" TYPEDEF

 

RECORDDEF =

"record" ARGLIST "end"

 

ARGLIST =

ARGDECL { ";" ARGDECL }

 

ARGDECL =

NAME ":" TYPEDEF

 

CLASSDEF =

"class" [ "(" NAME ")" ]

    [ "private" | "public" | "protected" ]

    [ ARGLIST ";" ]

    [ METHODDECL { ";" METHODDECL } ";" ]

    [ "property" NAME [ "[" ARGLIST "]" ] ":" TYPEDEF [ "read" NAME ] [ "write" NAME ] ";" ] [ "default" ";" ]

"end"

 

METHODDECL =

[ "class" ] "procedure" NAME ["(" [ARGLIST] ")"] [ ";" "override" | "virtual" | "reintroduce" ] |

[ "class" ] "function" NAME ["(" [ARGLIST] ")"] ":" TYPEDEF [ ";" "override" | "virtual" | "reintroduce" ] |

"constructor" NAME ["(" [ARGLIST] ")"] [ ";" "override" | "virtual" | "reintroduce" ] |

"destructor" NAME ["(" [ARGLIST] ")"] [ ";" "override" | "virtual" | "reintroduce" ]

 

PROCDECL =

PROCHEAD ";" PROCBODY |

PROCHEAD ";" "forward" |

METHODDEF ";" PROCBODY

 

PROCHEAD

"procedure" NAME ["(" [ARGLIST] ")"]

"function" NAME ["(" [ARGLIST] ")"] ":" TYPEDEF

 

PROCBODY =

{VARDECL ";"} "begin" SCRIPT "end"

 

METHODDEF =

[ "class" ] "procedure" NAME "." NAME ["(" [ARGLIST] ")"] |

[ "class" ] "function" NAME "." NAME ["(" [ARGLIST] ")"] ":" TYPEDEF |

"constructor" NAME "." NAME ["(" [ARGLIST] ")"] |

"destructor" NAME "." NAME ["(" [ARGLIST] ")"]

 

CONSTDECL =

"const" NAME "=" EXPR

 

BLOCK =

"begin" [STATEMENT {";" STATEMENT} [";"]] "end" |

INSTR

 

INSTR =

"if" EXPR "then" BLOCK |

"if" EXPR "then" BLOCK "else" BLOCK |

CASEINSTR |

"for" VAR ":=" EXPR "to" EXPR "do" BLOCK |

"for" VAR ":=" EXPR "downto" EXPR "do" BLOCK |

"while" EXPR "do" BLOCK |

"repeat" [BLOCK {";" BLOCK} [";"]] "until" EXPR |

VAR ":=" EXPR |

FUNC |

EXCEPT |

FINALLY |

BLOCK

 

CASECOND =

EXPR |

EXPR ".." EXPR |

 

CASEINSTR =

"case" EXPR "of"

  { CASECOND {"," CASECOND } : BLOCK ";" }

  [ "default" ":" BLOCK ";" ]

"end"

 

FUNC =

NAME [ "(" [EXPR {, EXPR}] ")" ]

 

EXCEPT =

"try"

  BLOCK { ";" BLOCK } [ ";" ]

"except"

  { "on" NAME ":" NAME "do" BLOCK; }

"end"

 

FINALLY =

"try"

  BLOCK { ";" BLOCK } [ ";" ]

"finally"

  { "on" NAME ":" NAME "do" BLOCK; }

"end"

 

EXPR =

EXPRADD [ "=" | "+" | "-" | "OR" EXPRADD]

 

EXPRADD =

EXPRMUL [ "+" | "-" | "OR" EXPRADD]

 

EXPRMUL =

TERM [ "*" | "/" | "mod" | "div" EXPRMUL]

 

TERM =

"+" TERM |

"-" TERM |

"not" TERM |

CONST |

VAR |

FUNC |

"(" EXPR ")"

"[" [ EXPR { "," EXPR } ] "]"

 

CONST =

INT |

HEXINT |

FLOAT |

STR |

CHAR |

"True" |

"False"

 

VAR =

NAME |

NAME "[" INT "]" |

NAME "." VAR |

VAR "." FUNC

 

NAME =

LIT {LIT | "0".."9" | "_"}

 

LIT =

"A".."Z", "a".."z"

 

STR =

CHAR |

STRING { CHAR [ STRING ] }

 

STRING =

" ' " { STRINGCHAR } " ' " { " ' " STRING }

 

STRINGCHAR =

ASCII(0)..ASCII(255) - " ' " - ASCII(13) | " ' ' "

 

CHAR =

"#" INT | "#" HEXINT

 

HEXINT =

"$" HEXNUM { HEXNUM }

 

HEXNUM =

"0".."9"|"A".."F"|"a".."f"

 

FLOAT =

INT [ "." INT]  [ "E" | "e" ["+" | "-" ] INT ]

 

INT =

NUM {NUM}

 

NUM =

"0".."9"

 

 

Reserved Words

 

 

(This topic is from the DWS project and is distributed per the MOZILLA PUBLIC LICENSE Version 1.1.)