ladybird/AK/JsonParser.cpp
Andreas Kling 94ca55cefd Meta: Add license header to source files
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.

For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.

Going forward, all new source files should include a license header.
2020-01-18 09:45:54 +01:00

278 lines
6.9 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.
*/
#include <AK/JsonArray.h>
#include <AK/JsonObject.h>
#include <AK/JsonParser.h>
namespace AK {
static inline bool is_whitespace(char ch)
{
return ch == ' ' || ch == '\n' || ch == '\t' || ch == '\v' || ch == '\r';
}
char JsonParser::peek() const
{
if (m_index < m_input.length())
return m_input[m_index];
return '\0';
}
char JsonParser::consume()
{
if (m_index < m_input.length())
return m_input[m_index++];
return '\0';
}
template<typename C>
void JsonParser::consume_while(C condition)
{
while (condition(peek()))
consume();
}
void JsonParser::consume_whitespace()
{
consume_while([](char ch) { return is_whitespace(ch); });
}
void JsonParser::consume_specific(char expected_ch)
{
char consumed_ch = consume();
ASSERT(consumed_ch == expected_ch);
}
String JsonParser::consume_quoted_string()
{
consume_specific('"');
Vector<char, 1024> buffer;
for (;;) {
size_t peek_index = m_index;
char ch = 0;
for (;;) {
if (peek_index == m_input.length())
break;
ch = m_input[peek_index];
if (ch == '"' || ch == '\\')
break;
++peek_index;
}
if (peek_index != m_index) {
buffer.append(m_input.characters_without_null_termination() + m_index, peek_index - m_index);
m_index = peek_index;
}
if (ch == '"')
break;
if (ch != '\\') {
buffer.append(consume());
continue;
}
consume();
char escaped_ch = consume();
switch (escaped_ch) {
case 'n':
case 'r':
buffer.append('\n');
break;
case 't':
buffer.append('\t');
break;
case 'b':
buffer.append('\b');
break;
case 'f':
buffer.append('\f');
break;
case 'u':
consume();
consume();
consume();
consume();
// FIXME: This is obviously not correct, but we don't have non-ASCII support so meh.
buffer.append('?');
break;
default:
buffer.append(escaped_ch);
break;
}
}
consume_specific('"');
if (buffer.is_empty())
return String::empty();
auto& last_string_starting_with_character = m_last_string_starting_with_character[(u8)buffer.first()];
if (last_string_starting_with_character.length() == (size_t)buffer.size()) {
if (!memcmp(last_string_starting_with_character.characters(), buffer.data(), buffer.size()))
return last_string_starting_with_character;
}
last_string_starting_with_character = String::copy(buffer);
return last_string_starting_with_character;
}
JsonObject JsonParser::parse_object()
{
JsonObject object;
consume_specific('{');
for (;;) {
consume_whitespace();
if (peek() == '}')
break;
consume_whitespace();
auto name = consume_quoted_string();
consume_whitespace();
consume_specific(':');
consume_whitespace();
auto value = parse();
object.set(name, move(value));
consume_whitespace();
if (peek() == '}')
break;
consume_specific(',');
}
consume_specific('}');
return object;
}
JsonArray JsonParser::parse_array()
{
JsonArray array;
consume_specific('[');
for (;;) {
consume_whitespace();
if (peek() == ']')
break;
array.append(parse());
consume_whitespace();
if (peek() == ']')
break;
consume_specific(',');
}
consume_whitespace();
consume_specific(']');
return array;
}
JsonValue JsonParser::parse_string()
{
return consume_quoted_string();
}
JsonValue JsonParser::parse_number()
{
Vector<char, 128> number_buffer;
for (;;) {
char ch = peek();
if (ch == '-' || (ch >= '0' && ch <= '9')) {
number_buffer.append(ch);
++m_index;
continue;
}
break;
}
StringView number_string(number_buffer.data(), number_buffer.size());
bool ok;
auto value = JsonValue(number_string.to_uint(ok));
if (!ok)
value = JsonValue(number_string.to_int(ok));
ASSERT(ok);
return value;
}
void JsonParser::consume_string(const char* str)
{
for (size_t i = 0, length = strlen(str); i < length; ++i)
consume_specific(str[i]);
}
JsonValue JsonParser::parse_true()
{
consume_string("true");
return JsonValue(true);
}
JsonValue JsonParser::parse_false()
{
consume_string("false");
return JsonValue(false);
}
JsonValue JsonParser::parse_null()
{
consume_string("null");
return JsonValue(JsonValue::Type::Null);
}
JsonValue JsonParser::parse_undefined()
{
consume_string("undefined");
return JsonValue(JsonValue::Type::Undefined);
}
JsonValue JsonParser::parse()
{
consume_whitespace();
auto type_hint = peek();
switch (type_hint) {
case '{':
return parse_object();
case '[':
return parse_array();
case '"':
return parse_string();
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
return parse_number();
case 'f':
return parse_false();
case 't':
return parse_true();
case 'n':
return parse_null();
case 'u':
return parse_undefined();
}
return JsonValue();
}
}