Simple precedence grammar
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A simple precedence grammar is a context-free formal grammar that can be parsed with a simple precedence parser.
Contents |
[edit] Formal definition
G = (N, Σ, P, S) is a simple precedence grammar if all the production rules in P comply with the following constraints:
- There are no erasing rules (ε-productions)
- There are no useless rules (unreacheable symbols or unproductives rules)
- For each pair of symbols X, Y (X, Y (N ∪ Σ)) there is only one Wirth-Weber precedence relation.
- G is uniquely inversible
[edit] Examples
[edit] Example 1
precedence table:
S | a | b | c | $ | |
S | |||||
a | |||||
b | |||||
c | |||||
$ |