// The MIT License (MIT)
// 
// Copyright (c) 2014 Todd Ditchendorf
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy 
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is 
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#import <Foundation/Foundation.h>
#import "PKSymbolNode.h"

@class PKReader;

/*!
    @class      PKSymbolRootNode 
    @brief      This class is a special case of a <tt>PKSymbolNode</tt>.
    @details    This class is a special case of a <tt>PKSymbolNode</tt>. A <tt>PKSymbolRootNode</tt> object has no symbol of its own, but has children that represent all possible symbols.
*/
@interface PKSymbolRootNode : PKSymbolNode

/*!
    @brief      Adds the given string as a multi-character symbol.
    @param      s a multi-character symbol that should be recognized as a single symbol token by this state
*/
- (void)add:(NSString *)s;

/*!
    @brief      Removes the given string as a multi-character symbol.
    @param      s a multi-character symbol that should no longer be recognized as a single symbol token by this state
    @details    if <tt>s</tt> was never added as a multi-character symbol, this has no effect
*/
- (void)remove:(NSString *)s;

/*!
    @brief      Return a symbol string from a reader.
    @param      r the reader from which to read
    @param      cin the character from witch to start
    @result     a symbol string from a reader
*/
- (NSString *)nextSymbol:(PKReader *)r startingWith:(PKUniChar)cin;
@end
