Synopsis Reserve is a conditional Symbol, constraining the set of strings that a symbol may produce.
Syntax
-
Symbol \ constraint
constraint is any character class, a literal or a keyword non-terminal Symbol.
Description The parser will not accept a reserve symbol if the string accepted by it matches exactly with the constraint. For example,
[a-z0-9]+ \ "if" will accept all strings of alphanumeric characters, except for the word if.