351 lines
10 KiB
C++

#pragma once
#include <cassert>
#include <deque>
#include "Utils/ClassUtils.h"
#include "Parsing/ILexer.h"
#include "Parsing/IParserLineStream.h"
#include "Parsing/ParsingException.h"
template <typename TokenType>
class AbstractLexer : public ILexer<TokenType>
{
// TokenType must inherit IParserValue
static_assert(std::is_base_of<IParserValue, TokenType>::value);
protected:
std::deque<TokenType> m_token_cache;
std::deque<ParserLine> m_line_cache;
IParserLineStream* const m_stream;
unsigned m_line_index;
unsigned m_current_line_offset;
explicit AbstractLexer(IParserLineStream* stream)
: m_stream(stream),
m_line_index(0u),
m_current_line_offset(0u)
{
}
virtual TokenType GetNextToken() = 0;
int NextChar()
{
while (true)
{
while (m_line_index >= m_line_cache.size())
{
if (!m_line_cache.empty() && m_line_cache.back().IsEof())
return EOF;
m_line_cache.push_back(m_stream->NextLine());
}
if (m_current_line_offset >= m_line_cache[m_line_index].m_line.size())
{
m_line_index++;
m_current_line_offset = 0;
}
else
break;
}
return m_line_cache[m_line_index].m_line[m_current_line_offset++];
}
int PeekChar()
{
auto peekLineOffset = m_current_line_offset;
auto peekLine = m_line_index;
while (true)
{
while (peekLine >= m_line_cache.size())
{
if (!m_line_cache.empty() && m_line_cache.back().IsEof())
return EOF;
m_line_cache.push_back(m_stream->NextLine());
}
if (peekLineOffset >= m_line_cache[peekLine].m_line.size())
{
peekLine++;
peekLineOffset = 0;
}
else
break;
}
return m_line_cache[peekLine].m_line[peekLineOffset];
}
_NODISCARD const ParserLine& CurrentLine() const
{
return m_line_cache[m_line_index];
}
_NODISCARD bool IsLineEnd() const
{
return m_current_line_offset >= CurrentLine().m_line.size();
}
_NODISCARD bool NextCharInLineIs(const char c)
{
return !IsLineEnd() && PeekChar() == c;
}
_NODISCARD TokenPos GetPreviousCharacterPos() const
{
const auto& currentLine = CurrentLine();
return TokenPos(*currentLine.m_filename, currentLine.m_line_number, m_current_line_offset);
}
_NODISCARD TokenPos GetNextCharacterPos()
{
const auto& currentLine = CurrentLine();
if (m_current_line_offset + 1 >= currentLine.m_line.size())
{
PeekChar();
return TokenPos(*m_line_cache.back().m_filename, m_line_cache.back().m_line_number, 1);
}
return TokenPos(*currentLine.m_filename, currentLine.m_line_number, m_current_line_offset + 1);
}
/**
* \brief Reads an identifier from the current position
* \return The value of the read identifier
*/
std::string ReadIdentifier()
{
const auto& currentLine = CurrentLine();
assert(m_current_line_offset >= 1);
assert(isalpha(currentLine.m_line[m_current_line_offset - 1]) || currentLine.m_line[m_current_line_offset - 1] == '_');
const auto startPos = m_current_line_offset - 1;
const auto lineSize = currentLine.m_line.size();
while (m_current_line_offset < lineSize)
{
const auto c = currentLine.m_line[m_current_line_offset];
if (!isalnum(c) && c != '_')
break;
m_current_line_offset++;
}
return std::string(currentLine.m_line, startPos, m_current_line_offset - startPos);
}
/**
* \brief Reads an identifier from the current position
* \return The value of the read identifier
*/
std::string ReadString()
{
const auto& currentLine = CurrentLine();
assert(m_current_line_offset >= 1);
assert(currentLine.m_line[m_current_line_offset - 1] == '"');
const auto startPos = m_current_line_offset;
const auto lineSize = currentLine.m_line.size();
while (true)
{
if (m_current_line_offset >= lineSize)
throw ParsingException(TokenPos(*currentLine.m_filename, currentLine.m_line_number, m_current_line_offset), "Unclosed string");
if (currentLine.m_line[m_current_line_offset] == '\"')
break;
m_current_line_offset++;
}
return std::string(currentLine.m_line, startPos, m_current_line_offset++ - startPos);
}
void ReadHexNumber(int& integerValue)
{
const auto& currentLine = CurrentLine();
const auto* start = &currentLine.m_line.c_str()[m_current_line_offset - 1];
char* end;
integerValue = static_cast<int>(std::strtoul(start, &end, 16));
const auto numberLength = static_cast<unsigned>(end - start);
if (numberLength == 0 || isalnum(*end) || *end == '_')
throw ParsingException(GetPreviousCharacterPos(), "Invalid hex number");
m_current_line_offset += numberLength - 1;
}
_NODISCARD bool IsIntegerNumber() const
{
const auto& currentLine = CurrentLine();
const auto* currentCharacter = &currentLine.m_line.c_str()[m_current_line_offset - 1];
auto isInteger = true;
auto dot = false;
auto exponent = false;
if (*currentCharacter == '-' || *currentCharacter == '+')
++currentCharacter;
while (*currentCharacter)
{
if (isdigit(*currentCharacter))
{
}
else if (*currentCharacter == '.')
{
if (dot)
throw ParsingException(GetPreviousCharacterPos(), "Invalid number");
dot = true;
isInteger = false;
}
else if (*currentCharacter == 'e' || *currentCharacter == 'E')
{
if (exponent)
throw ParsingException(GetPreviousCharacterPos(), "Invalid number");
if (currentCharacter[1] == '-')
++currentCharacter;
exponent = true;
isInteger = false;
}
else if (isalpha(*currentCharacter))
{
throw ParsingException(GetPreviousCharacterPos(), "Invalid number");
}
else
{
break;
}
++currentCharacter;
}
return isInteger;
}
int ReadInteger()
{
const auto& currentLine = CurrentLine();
const auto* start = &currentLine.m_line.c_str()[m_current_line_offset - 1];
char* end;
const auto integerValue = std::strtol(start, &end, 10);
const auto numberLength = static_cast<unsigned>(end - start);
if (numberLength == 0)
throw ParsingException(GetPreviousCharacterPos(), "Invalid number");
m_current_line_offset += numberLength - 1;
return integerValue;
}
double ReadFloatingPoint()
{
const auto& currentLine = CurrentLine();
const auto* start = &currentLine.m_line.c_str()[m_current_line_offset - 1];
char* end;
const auto floatingPointValue = std::strtod(start, &end);
const auto numberLength = static_cast<unsigned>(end - start);
if (numberLength == 0)
throw ParsingException(GetPreviousCharacterPos(), "Invalid number");
m_current_line_offset += numberLength - 1;
return floatingPointValue;
}
void ReadNumber(bool& isFloatingPoint, double& floatingPointValue, int& integerValue)
{
const auto& currentLine = CurrentLine();
assert(m_current_line_offset >= 1);
assert(isdigit(currentLine.m_line[m_current_line_offset - 1])
|| currentLine.m_line[m_current_line_offset - 1] == '.'
|| currentLine.m_line[m_current_line_offset - 1] == '-');
const auto lineLength = currentLine.m_line.size();
if (lineLength - m_current_line_offset >= 1
&& currentLine.m_line[m_current_line_offset - 1] == '0'
&& currentLine.m_line[m_current_line_offset] == 'x')
{
isFloatingPoint = false;
ReadHexNumber(integerValue);
}
else if (IsIntegerNumber())
{
isFloatingPoint = false;
integerValue = ReadInteger();
}
else
{
isFloatingPoint = true;
floatingPointValue = ReadFloatingPoint();
}
}
public:
const TokenType& GetToken(unsigned index) override
{
while (index >= m_token_cache.size())
m_token_cache.emplace_back(GetNextToken());
return m_token_cache[index];
}
void PopTokens(int amount) override
{
if (amount <= 0 || m_token_cache.empty())
return;
if (static_cast<int>(m_token_cache.size()) <= amount)
{
const auto& lastToken = m_token_cache.back();
while (!m_line_cache.empty()
&& (m_line_cache.front().m_line_number != lastToken.GetPos().m_line
|| *m_line_cache.front().m_filename != lastToken.GetPos().m_filename.get()))
{
m_line_cache.pop_front();
m_line_index--;
}
m_token_cache.clear();
}
else
{
m_token_cache.erase(m_token_cache.begin(), m_token_cache.begin() + amount);
const auto& firstToken = m_token_cache.front();
while (m_line_cache.front().m_line_number != firstToken.GetPos().m_line
|| *m_line_cache.front().m_filename != firstToken.GetPos().m_filename.get())
{
m_line_cache.pop_front();
m_line_index--;
}
}
}
_NODISCARD bool IsEof() override
{
return GetToken(0).IsEof();
}
_NODISCARD const TokenPos& GetPos() override
{
return GetToken(0).GetPos();
}
_NODISCARD ParserLine GetLineForPos(const TokenPos& pos) const override
{
for (const auto& line : m_line_cache)
{
if (*line.m_filename == pos.m_filename.get()
&& line.m_line_number == pos.m_line)
return line;
}
return ParserLine();
}
};