File content as of revision 11:e1bee9a77652:

/*
 * Value.h
 *
 * Created on: Nov 1, 2013
 * * Authors: Vincent Wochnik <v.wochnik@gmail.com>
 *
 * Copyright (c) 2013 Cumulocity GmbH
 *
 * 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.
 */

/**
 * @file Value.h
 * Represents a generic data value.
 */

#ifndef VALUE_H
#define VALUE_H

#include "config.h"
#include <stddef.h>
#include <stdint.h>
#include "AbstractDataSink.h"

/** Return value indicating a null value. */
#define VALUE_NULL 0
/** Return value indicating an integer value. */
#define VALUE_INTEGER 1
/** Return value indicating a floating-point number. */
#define VALUE_FLOAT 2
/** Return value indicating a character string. */
#define VALUE_CHARACTER 3

/**
 * A generic value offering means to obtain the value type and contents
 * as well as writing the value to a sink.
 */
class Value
{
	public:
		virtual ~Value() { };

		/**
		 * Returns the value type which can be VALUE_NULL, VALUE_INTEGER,
		 * VALUE_FLOAT or VALUE_CHARACTER.
		 * @return the value type
		 */
		virtual uint8_t valueType() const = 0;

		/**
		 * Returns the integer value if an integer type, otherwise zero.
		 * @return integer value
		 */
		virtual long integerValue() const = 0;

		/**
		 * Returns the float value if a float type, otherwise zero.
		 * @return float value
		 */
		virtual double floatValue() const = 0;

		/**
		 * Returns the character value if a character type, otherwise zero.
		 * @return character value
		 */
		virtual const char * characterValue() const = 0;

		/**
		 * Writes the value to a sink.
		 * If necessary, quotes and escape characters may be added.
		 * @param sink the sink to write the value to
		 * @return the number of bytes written
		 */
		virtual size_t write(AbstractDataSink&) const = 0;

		/**
		 * Returns the number of bytes required to write this value to a sink.
		 * @return number of bytes required to write this value
		 */
		virtual size_t length() const = 0;

		/**
		 * Copies this value to the heap. Referenced contents must also be
		 * copied.
		 * @return a new value instance allocated on the heap
		 */
		virtual Value* copy() const = 0;
};

#endif