structured fields blab

structured-fields.blab

sf {

	sf-string = DQUOTE  chr*  DQUOTE

	sf-list = list-member  ( OWS "," OWS list-member )*

	list-member = sf-item
		| inner-list

	inner-list = "("  SP*  ( sf-item ( SP+ sf-item )* SP* )?  ")"  parameters

	parameters = ( ";" SP* parameter )*

	parameter = param-name  ( "=" param-value )?

	param-name = key

	key = lcalpha | "*"  ( lcalpha | DIGIT | "_" | "-" | "." | "*" )*

	lcalpha = "z" | "y" | "x" | "w" | "v" | "u" | "t" | "s" | "r" | "q" | "p" | "o" | "n" | "m" | "l" | "k" | "j" | "i" | "h" | "g" | "f" | "e" | "d" | "c" | "b" | "a"

	param-value = bare-item

	sf-dictionary = dict-member  ( OWS "," OWS dict-member )*

	dict-member = member-name  ( "=" member-value )?

	member-name = key

	member-value = sf-item
		| inner-list

	sf-item = bare-item  parameters

	bare-item = sf-integer
		| sf-decimal
		| sf-string
		| sf-token
		| sf-binary
		| sf-boolean

	sf-integer = ( "-" )?  DIGIT{1,15}

	sf-decimal = ( "-" )?  DIGIT{1,12}  "."  DIGIT{1,3}

	chr = unescaped
		| escaped

	unescaped = "!" | " "
		| "[" | "Z" | "Y" | "X" | "W" | "V" | "U" | "T" | "S" | "R" | "Q" | "P" | "O" | "N" | "M" | "L" | "K" | "J" | "I" | "H" | "G" | "F" | "E" | "D" | "C" | "B" | "A" | "@" | "?" | ">" | "=" | "<" | ";" | ":" | "9" | "8" | "7" | "6" | "5" | "4" | "3" | "2" | "1" | "0" | "/" | "." | "-" | "," | "+" | "*" | ")" | "(" | "\'" | "&" | "%" | "$" | "#"
		| "~" | "}" | "|" | "{" | "z" | "y" | "x" | "w" | "v" | "u" | "t" | "s" | "r" | "q" | "p" | "o" | "n" | "m" | "l" | "k" | "j" | "i" | "h" | "g" | "f" | "e" | "d" | "c" | "b" | "a" | "`" | "_" | "^" | "]"

	escaped = "\\" ( DQUOTE | "\\" )

	sf-token = ALPHA | "*"  ( tchar | ":" | "/" )*

	sf-binary = ":"   ":"

	base64 = ALPHA
		| DIGIT
		| "+"
		| "/"
		| "="

	sf-boolean = "?"  boolean

	boolean = "0"
		| "1"

	tchar = "!"
		| "#"
		| "$"
		| "%"
		| "&"
		| "\'"
		| "*"
		| "+"
		| "-"
		| "."
		| "^"
		| "_"
		| "`"
		| "|"
		| "~"
		| DIGIT
		| ALPHA

	OWS = ( SP | HTAB )*

	VCHAR = "~" | "}" | "|" | "{" | "z" | "y" | "x" | "w" | "v" | "u" | "t" | "s" | "r" | "q" | "p" | "o" | "n" | "m" | "l" | "k" | "j" | "i" | "h" | "g" | "f" | "e" | "d" | "c" | "b" | "a" | "`" | "_" | "^" | "]" | "\\" | "[" | "Z" | "Y" | "X" | "W" | "V" | "U" | "T" | "S" | "R" | "Q" | "P" | "O" | "N" | "M" | "L" | "K" | "J" | "I" | "H" | "G" | "F" | "E" | "D" | "C" | "B" | "A" | "@" | "?" | ">" | "=" | "<" | ";" | ":" | "9" | "8" | "7" | "6" | "5" | "4" | "3" | "2" | "1" | "0" | "/" | "." | "-" | "," | "+" | "*" | ")" | "(" | "\'" | "&" | "%" | "$" | "#" | "\"" | "!"

	SP = " "

	HTAB = "\t"

	DIGIT = "9" | "8" | "7" | "6" | "5" | "4" | "3" | "2" | "1" | "0"

	ALPHA = "Z" | "Y" | "X" | "W" | "V" | "U" | "T" | "S" | "R" | "Q" | "P" | "O" | "N" | "M" | "L" | "K" | "J" | "I" | "H" | "G" | "F" | "E" | "D" | "C" | "B" | "A"
		| "z" | "y" | "x" | "w" | "v" | "u" | "t" | "s" | "r" | "q" | "p" | "o" | "n" | "m" | "l" | "k" | "j" | "i" | "h" | "g" | "f" | "e" | "d" | "c" | "b" | "a"

	DQUOTE = "\""

}