/**
* Define the specified rule in the grammar. This method assigns the rule's {@link Rule#index}
* according to the {@link #ruleNumber} field, and adds the {@link Rule} instance to {@link
* #rules} and {@link #indexToRule}.
*
* @param r The rule to define in the grammar.
* @return {@code true} if the rule was added to the {@link Grammar} instance; otherwise, {@code
* false} if a rule with this name already existed in the grammar instance.
*/
public boolean defineRule(@NotNull Rule r) {
if (rules.get(r.name) != null) {
return false;
}
rules.put(r.name, r);
r.index = ruleNumber++;
indexToRule.add(r);
return true;
}
public Rule getRule(String name) {
Rule r = rules.get(name);
if (r != null) return r;
return null;
/*
List<Grammar> imports = getAllImportedGrammars();
if ( imports==null ) return null;
for (Grammar g : imports) {
r = g.getRule(name); // recursively walk up hierarchy
if ( r!=null ) return r;
}
return null;
*/
}
/**
* Undefine the specified rule from this {@link Grammar} instance. The instance {@code r} is
* removed from {@link #rules} and {@link #indexToRule}. This method updates the {@link
* Rule#index} field for all rules defined after {@code r}, and decrements {@link #ruleNumber} in
* preparation for adding new rules.
*
* <p>This method does nothing if the current {@link Grammar} does not contain the instance {@code
* r} at index {@code r.index} in {@link #indexToRule}.
*
* @param r
* @return {@code true} if the rule was removed from the {@link Grammar} instance; otherwise,
* {@code false} if the specified rule was not defined in the grammar.
*/
public boolean undefineRule(@NotNull Rule r) {
if (r.index < 0 || r.index >= indexToRule.size() || indexToRule.get(r.index) != r) {
return false;
}
assert rules.get(r.name) == r;
rules.remove(r.name);
indexToRule.remove(r.index);
for (int i = r.index; i < indexToRule.size(); i++) {
assert indexToRule.get(i).index == i + 1;
indexToRule.get(i).index--;
}
ruleNumber--;
return true;
}
public void defineRule(Rule r) {
if (rules.get(r.name) != null) return;
rules.put(r.name, r);
r.index = ruleNumber++;
indexToRule.add(r);
}