http://www.snakeyaml.org: YAML 1.1 parser and emitter for Java
  • Andrey Somov
  • Alexander Maslov
  • Jordan Angold 
Copyright (c) 2008, http://www.snakeyaml.org
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

/**
 * Copyright (c) 2008, http://www.snakeyaml.org
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.yaml.snakeyaml.scanner;

import org.yaml.snakeyaml.tokens.Token;


This interface represents an input stream of Tokens. 

The parser and the scanner form together the 'Parse' step in the loading
process (see chapter 3.1 of the YAML
Specification).



See Also:
/**
 * This interface represents an input stream of {@link Token}s.
 * <p>
 * The parser and the scanner form together the 'Parse' step in the loading
 * process (see chapter 3.1 of the <a href="http://yaml.org/spec/1.1/">YAML
 * Specification</a>).
 * </p>
 *
 * @see org.yaml.snakeyaml.tokens.Token
 */
public interface Scanner {

    
Check if the next token is one of the given types.

Params:
  • choices – 
           token IDs.
Throws:
Returns:true if the next token can be assigned to a variable
        of at least one of the given types. Returns false if
        no more tokens are available.
/**
     * Check if the next token is one of the given types.
     *
     * @param choices
     *            token IDs.
     * @return <code>true</code> if the next token can be assigned to a variable
     *         of at least one of the given types. Returns <code>false</code> if
     *         no more tokens are available.
     * @throws ScannerException
     *             Thrown in case of malformed input.
     */
    boolean checkToken(Token.ID... choices);

    
Return the next token, but do not delete it from the stream. The method must be called only after checkToken. 
Throws:
Returns:The token that will be returned on the next call to getToken
/**
     * Return the next token, but do not delete it from the stream.
     * The method must be called only after {@link #checkToken}.
     *
     * @return The token that will be returned on the next call to {@link #getToken}
     * @throws ScannerException          Thrown in case of malformed input.
     * @throws IndexOutOfBoundsException if no more token left
     */
    Token peekToken();

    
Returns the next token.

 The token will be removed from the stream. (Every invocation of this method must happen after calling checkToken. 


Throws:
Returns:the coming token
/**
     * Returns the next token.
     * <p>
     * The token will be removed from the stream.
     * (Every invocation of this method must happen after calling {@link #checkToken}.
     * </p>
     *
     * @return the coming token
     * @throws ScannerException          Thrown in case of malformed input.
     * @throws IndexOutOfBoundsException if no more token left
     */
    Token getToken();
}