ladybird/AK/JsonValue.h
Matthew Olsson e8e728454c AK: JsonParser improvements
- Parsing invalid JSON no longer asserts
    Instead of asserting when coming across malformed JSON,
    JsonParser::parse now returns an Optional<JsonValue>.
- Disallow trailing commas in JSON objects and arrays
- No longer parse 'undefined', as that is a purely JS thing
- No longer allow non-whitespace after anything consumed by the initial
  parse() call. Examples of things that were valid and no longer are:
    - undefineddfz
    - {"foo": 1}abcd
    - [1,2,3]4
- JsonObject.for_each_member now iterates in original insertion order
2020-06-13 12:43:22 +02:00

267 lines
6.5 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/Forward.h>
#include <AK/IPv4Address.h>
#include <AK/Optional.h>
#include <AK/String.h>
#include <AK/StringBuilder.h>
namespace AK {
class JsonValue {
public:
enum class Type {
Null,
Int32,
UnsignedInt32,
Int64,
UnsignedInt64,
#if !defined(KERNEL)
Double,
#endif
Bool,
String,
Array,
Object,
};
static Optional<JsonValue> from_string(const StringView&);
explicit JsonValue(Type = Type::Null);
~JsonValue() { clear(); }
JsonValue(const JsonValue&);
JsonValue(JsonValue&&);
JsonValue& operator=(const JsonValue&);
JsonValue& operator=(JsonValue&&);
JsonValue(int);
JsonValue(unsigned);
JsonValue(long);
JsonValue(long unsigned);
JsonValue(long long);
JsonValue(long long unsigned);
#if !defined(KERNEL)
JsonValue(double);
#endif
JsonValue(bool);
JsonValue(const char*);
JsonValue(const String&);
JsonValue(const IPv4Address&);
JsonValue(const JsonArray&);
JsonValue(const JsonObject&);
JsonValue(JsonArray&&);
JsonValue(JsonObject&&);
// FIXME: Implement these
JsonValue& operator=(JsonArray&&) = delete;
JsonValue& operator=(JsonObject&&) = delete;
template<typename Builder>
typename Builder::OutputType serialized() const;
template<typename Builder>
void serialize(Builder&) const;
String as_string_or(const String& alternative)
{
if (is_string())
return as_string();
return alternative;
}
String to_string() const
{
if (is_string())
return as_string();
return serialized<StringBuilder>();
}
Optional<IPv4Address> to_ipv4_address() const
{
if (!is_string())
return {};
return IPv4Address::from_string(as_string());
}
int to_int(int default_value = 0) const { return to_i32(default_value); }
i32 to_i32(i32 default_value = 0) const { return to_number<i32>(default_value); }
unsigned to_uint(unsigned default_value = 0) const { return to_u32(default_value); }
u32 to_u32(u32 default_value = 0) const { return to_number<u32>(default_value); }
bool to_bool(bool default_value = false) const
{
if (!is_bool())
return default_value;
return as_bool();
}
i32 as_i32() const
{
ASSERT(is_i32());
return m_value.as_i32;
}
u32 as_u32() const
{
ASSERT(is_u32());
return m_value.as_u32;
}
i64 as_i64() const
{
ASSERT(is_i64());
return m_value.as_i64;
}
u64 as_u64() const
{
ASSERT(is_u64());
return m_value.as_u64;
}
int as_bool() const
{
ASSERT(is_bool());
return m_value.as_bool;
}
String as_string() const
{
ASSERT(is_string());
return *m_value.as_string;
}
const JsonObject& as_object() const
{
ASSERT(is_object());
return *m_value.as_object;
}
const JsonArray& as_array() const
{
ASSERT(is_array());
return *m_value.as_array;
}
#if !defined(KERNEL)
double as_double() const
{
ASSERT(is_double());
return m_value.as_double;
}
#endif
Type type() const
{
return m_type;
}
bool is_null() const { return m_type == Type::Null; }
bool is_bool() const { return m_type == Type::Bool; }
bool is_string() const { return m_type == Type::String; }
bool is_i32() const { return m_type == Type::Int32; }
bool is_u32() const { return m_type == Type::UnsignedInt32; }
bool is_i64() const { return m_type == Type::Int64; }
bool is_u64() const { return m_type == Type::UnsignedInt64; }
#if !defined(KERNEL)
bool is_double() const
{
return m_type == Type::Double;
}
#endif
bool is_array() const
{
return m_type == Type::Array;
}
bool is_object() const { return m_type == Type::Object; }
bool is_number() const
{
switch (m_type) {
case Type::Int32:
case Type::UnsignedInt32:
case Type::Int64:
case Type::UnsignedInt64:
#if !defined(KERNEL)
case Type::Double:
#endif
return true;
default:
return false;
}
}
template<typename T>
T to_number(T default_value = 0) const
{
#if !defined(KERNEL)
if (is_double())
return (T)as_double();
#endif
if (type() == Type::Int32)
return (T)as_i32();
if (type() == Type::UnsignedInt32)
return (T)as_u32();
if (type() == Type::Int64)
return (T)as_i64();
if (type() == Type::UnsignedInt64)
return (T)as_u64();
return default_value;
}
bool equals(const JsonValue& other) const;
private:
void clear();
void copy_from(const JsonValue&);
Type m_type { Type::Null };
union {
StringImpl* as_string { nullptr };
JsonArray* as_array;
JsonObject* as_object;
#if !defined(KERNEL)
double as_double;
#endif
i32 as_i32;
u32 as_u32;
i64 as_i64;
u64 as_u64;
bool as_bool;
} m_value;
};
}
using AK::JsonValue;