Wirth syntax notation is a grammar language created in 1977.
| #2829on PLDB | 47Years Old |
Wirth syntax notation (WSN) is a metasyntax, that is, a formal way to describe formal languages. Originally proposed by Niklaus Wirth in 1977 as an alternative to Backus–Naur form (BNF). It has several advantages over BNF in that it contains an explicit iteration construct, and it avoids the use of an explicit symbol for the empty string (such as
SYNTAX = { PRODUCTION } .
PRODUCTION = IDENTIFIER "=" EXPRESSION "." .
EXPRESSION = TERM { "|" TERM } .
TERM = FACTOR { FACTOR } .
FACTOR = IDENTIFIER
| LITERAL
| "[" EXPRESSION "]"
| "(" EXPRESSION ")"
| "{" EXPRESSION "}" .
IDENTIFIER = letter { letter } .
LITERAL = """" character { character } """" .