Formal syntax for the grammar: Reference

Grammar functions are used in expressions when customizing field mappings through Source Manager. Use the following syntax for the grammar:

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

The identifier tokens correspond to what IMPAX can return as an identifier. The + operator corresponds to the concatenation operation. For languages that make use of the extended characters of the ISO 8859-1 character set, the ASCII token class is extended to include those extended characters.