Slide 57 of 115
Notes:
The expression must match the following syntax (given as a BNF grammar notation):
expr ::= "true" | "false"
| "!" expr
| expr "&&" expr
| expr "||" expr
| "(" expr ")"
| comp
comp ::= word "==" word | word "eq" word
| word "!=" word | word "ne" word
| word "<" word | word "lt" word
| word "<=" word | word "le" word
| word ">" word | word "gt" word
| word ">=" word | word "ge" word
| word "in" "{" wordlist "}"
| word "=~" regex
| word "!~" regex
wordlist ::= word
| wordlist "," word
word ::= digit
| cstring
| variable
| function
digit ::= [0-9]+
cstring ::= "..."
variable ::= "%{" varname "}"
function ::= funcname "(" funcargs ")"
