lang/c++/api/Types.hh

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
 *
 *     https://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.
 */

#ifndef avro_Types_hh__
#define avro_Types_hh__

#include <iostream>

#include "Config.hh"

namespace avro {

/**
 * The "type" for the schema.
 */
enum Type {

    AVRO_STRING,    /*!< String */
    AVRO_BYTES,     /*!< Sequence of variable length bytes data */
    AVRO_INT,       /*!< 32-bit integer */
    AVRO_LONG,      /*!< 64-bit integer */
    AVRO_FLOAT,     /*!< Floating point number */
    AVRO_DOUBLE,    /*!< Double precision floating point number */
    AVRO_BOOL,      /*!< Boolean value */
    AVRO_NULL,      /*!< Null */

    AVRO_RECORD,    /*!< Record, a sequence of fields */
    AVRO_ENUM,      /*!< Enumeration */
    AVRO_ARRAY,     /*!< Homogeneous array of some specific type */
    AVRO_MAP,       /*!< Homogeneous map from string to some specific type */
    AVRO_UNION,     /*!< Union of one or more types */
    AVRO_FIXED,     /*!< Fixed number of bytes */

    AVRO_NUM_TYPES, /*!< Marker */
    
    // The following is a pseudo-type used in implementation
    
    AVRO_SYMBOLIC = AVRO_NUM_TYPES, /*!< User internally to avoid circular references. */
    AVRO_UNKNOWN  = -1 /*!< Used internally. */

};

/**
 * Returns true if and only if the given type is a primitive.
 * Primitive types are: string, bytes, int, long, float, double, boolean
 * and null
 */
inline bool isPrimitive(Type t) {
    return (t >= AVRO_STRING) && (t < AVRO_RECORD);
}

/**
 * Returns true if and only if the given type is a non primitive valid type.
 * Primitive types are: string, bytes, int, long, float, double, boolean
 * and null
 */
inline bool isCompound(Type t) {
    return (t>= AVRO_RECORD) && (t < AVRO_NUM_TYPES);
}

/**
 * Returns true if and only if the given type is a valid avro type.
 */
inline bool isAvroType(Type t) {
    return (t >= AVRO_STRING) && (t < AVRO_NUM_TYPES);
}

/**
 * Returns true if and only if the given type is within the valid range
 * of enumeration.
 */
inline bool isAvroTypeOrPseudoType(Type t) {
    return (t >= AVRO_STRING) && (t <= AVRO_NUM_TYPES);
}

/**
 * Converts the given type into a string. Useful for generating messages.
 */
AVRO_DECL const std::string& toString(Type type);

/**
 * Writes a string form of the given type into the given ostream.
 */
AVRO_DECL std::ostream &operator<< (std::ostream &os, avro::Type type);

/// define a type to identify Null in template functions
struct AVRO_DECL Null { };

/**
 * Writes schema for null \p null type to \p os.
 * \param os The ostream to write to.
 * \param null The value to be written.
 */
std::ostream& operator<< (std::ostream &os, const Null &null);

} // namespace avro


#endif