TestGrammar2.java

package com.github.parboiled1.grappa.samples;

import com.github.parboiled1.grappa.parsers.EventBusParser;
import org.parboiled.Rule;
import org.parboiled.support.Var;

import java.util.HashMap;
import java.util.Map;

public class TestGrammar2
    extends EventBusParser<String>
{
    protected final Map<String, String> collectedValues
        = new HashMap<String, String>();
    protected final Var<String> var = new Var<String>();

    Rule key()
    {
        return sequence(
            firstOf(ignoreCase("sno"), ignoreCase("sname")),
            var.set(match().toLowerCase()),
            !collectedValues.containsKey(var.get())
        );
    }

    Rule separator()
    {
        return optional(anyOf(":-*_ "));
    }

    Rule value()
    {
        return sequence(
            oneOrMore(testNot(wsp()), ANY),
            collectedValues.put(var.get(), match()) == null
        );
    }

    Rule oneLine()
    {
        return join(sequence(key(), separator(), value()))
            .using(oneOrMore(wsp()))
            .min(2);
    }
}