@NotNull
@Override
public Pair<R, State> parse(@NotNull List<Token<T>> tokens, @NotNull State state)
throws ParserException {
if (myKey != state.getKey()) {
myKey = state.getKey();
myCache.clear();
}
final SoftReference<Pair<R, State>> ref = myCache.get(state.getPos());
final Pair<R, State> cached = SoftReference.dereference(ref);
if (cached != null) {
return cached;
}
final Pair<R, State> result = myParser.parse(tokens, state);
myCache.put(state.getPos(), new SoftReference<Pair<R, State>>(result));
return result;
}
@NotNull
@Override
public Pair<R, State> parse(@NotNull List<Token<T>> tokens, @NotNull State state)
throws ParserException {
try {
return myFirst.parse(tokens, state);
} catch (ParserException e) {
return mySecond.parse(tokens, new State(state, state.getPos(), e.getState().getMax()));
}
}
@NotNull
@Override
public Pair<Object, State> parse(@NotNull List<Token<T>> tokens, @NotNull State state)
throws ParserException {
final int pos = state.getPos();
if (pos >= tokens.size()) {
return Pair.create(null, state);
}
throw new ParserException(
String.format("Expected end of input, found %s", tokens.get(pos)), state);
}
@NotNull
@Override
public Pair<List<R>, State> parse(@NotNull List<Token<T>> tokens, @NotNull State state)
throws ParserException {
final List<R> list = new ArrayList<R>();
try {
//noinspection InfiniteLoopStatement
while (true) {
final Pair<R, State> result = myParser.parse(tokens, state);
state = result.getSecond();
list.add(result.getFirst());
}
} catch (ParserException e) {
return Pair.create(list, new State(state, state.getPos(), e.getState().getMax()));
}
}
@NotNull
@Override
public Pair<Token<T>, State> parse(@NotNull List<Token<T>> tokens, @NotNull State state)
throws ParserException {
final int pos = state.getPos();
if (pos >= tokens.size()) {
throw new ParserException("No tokens left", state);
}
final Token<T> token = tokens.get(pos);
if (token.getType().equals(myType) && (myText == null || token.getText().equals(myText))) {
final int newPos = pos + 1;
final State newState = new State(state, newPos, Math.max(newPos, state.getMax()));
return Pair.create(token, newState);
}
final String expected =
myText != null
? String.format("Token(<%s>, \"%s\")", myType, myText)
: String.format("Token(<%s>)", myType);
throw new ParserException(String.format("Expected %s, found %s", expected, token), state);
}
