Class NullableChecker

java.lang.Object
relaxngcc.builder.NullableChecker

public class NullableChecker extends Object
Computes the nullability of scopes.

A state s is said to be "reachable by epsilon" if

  1. it is an initial state, or
  2. a state s' is nullable, and there is a transition from s' to s by ref[X], and X is nullable.

We say an automaton X is nullable if one of its final state is "reachable by epsilon." Informally, this means X can accept the empty tree.

Author:
Kohsuke Kawaguchi (kk@kohsuke.org)
  • Constructor Details

    • NullableChecker

      public NullableChecker()
  • Method Details

    • computeNullability

      public static void computeNullability(NGCCGrammar gram)