Difference between revisions of "BNF - Syntax Diagrams"
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Revision as of 20:09, 21 May 2017
BNF
Backus Naur Form is a way of describing the syntax of a value to form a new value.
For example:
<digit> ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
This declares that <digit> can only be the numbers 0-9, specifically 0 OR 1 OR 2 OR 3 etc.
This notation can also be recursive:
<integer> ::= <digit> | <digit><integer>
This states that an integer can be a digit or a digit followed by another integer.
Syntax Diagrams
These are a diagram approach similar to BNF, they also describe the syntax allowed.
A recursive example:
