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Library for use in Java components of Vespa. Shared code which do not fit anywhere else.

There is a newer version: 8.409.18

// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.text;

/**
 * Superclasses of parsers of a map represented textually as
 * {key1:value1,"anystringkey":value2,'anystringkey2':value3 ...}.
 * This parser must be extended to specify how to handle the key/value pairs.
 *
 * Example: To create a Double map parser:
 *  * public static final class DoubleMapParser extends MapParser<Double> {
 *     private Map<String, Double> map;
 *
 *     ...
 *
 *     @Override
 *     protected Double handleKeyValue(String key, String value) {
 *         map.put(key, Double.parseDouble(value));
 *     }
 *
 * }
 * 
 *
 * Map parsers are NOT multithread safe, but are cheap to construct.
 *
 * @author bratseth
 */
public abstract class SimpleMapParser {

    private PositionedString s;

    /**
     * Parses a map on the form {key1:value1,key2:value2 ...}
     *
     * @param string the textual representation of the map
     */
    public void parse(String string) {
        try {
            this.s=new PositionedString(string);

            s.consumeSpaces();
            s.consume('{');
            while ( ! s.peek('}')) {
                s.consumeSpaces();
                String key=consumeKey();
                s.consume(':');
                s.consumeSpaces();
                consumeValue(key);
                s.consumeOptional(',');
                s.consumeSpaces();
            }
            s.consume('}');
        }
        catch (IllegalArgumentException e) {
            throw new IllegalArgumentException("'" + s + "' is not a legal sparse vector string",e);
        }
    }

    private String consumeKey() {
        if (s.consumeOptional('"')) {
            String key=s.consumeTo('"');
            s.consume('"');
            return key;
        }
        else if (s.consumeOptional('\'')) {
            String key=s.consumeTo('\'');
            s.consume('\'');
            return key;
        }
        else {
            int keyEnd=findEndOfKey();
            if (keyEnd<0)
                throw new IllegalArgumentException("Expected a key followed by ':' " + s.at());
            return s.consumeToPosition(keyEnd);
        }
    }

    protected int findEndOfKey() {
        for (int peekI=s.position(); peekI