Refactoring of Parser class with std::istreambuf_iterator.

This commit is contained in:
Patrick Lühne 2016-05-30 12:54:56 +02:00
parent 8d879344f2
commit 4d984d32c3
2 changed files with 23 additions and 27 deletions

View File

@ -18,16 +18,13 @@ namespace utils
class Parser
{
public:
using CharacterType = unsigned char;
public:
explicit Parser(std::istream &istream);
size_t row() const;
size_t column() const;
CharacterType currentCharacter() const;
char currentCharacter() const;
void advance();
bool atEndOfFile() const;
@ -52,17 +49,17 @@ class Parser
std::string getLine();
private:
static const std::istream_iterator<CharacterType> EndOfFile;
static const std::istreambuf_iterator<char> EndOfFile;
private:
void checkStream() const;
bool advanceIf(CharacterType expectedCharacter);
bool advanceIf(char expectedCharacter);
uint64_t parseIntegerBody();
std::istream &m_istream;
std::istream_iterator<CharacterType> m_position;
std::istreambuf_iterator<char> m_position;
size_t m_row;
size_t m_column;
@ -81,7 +78,7 @@ std::string Parser::parseIdentifier(CharacterPredicate characterPredicate, White
while (true)
{
const auto character = *m_position;
const auto character = currentCharacter();
if (!characterPredicate(character))
return value;
@ -110,7 +107,7 @@ void Parser::skipWhiteSpace(WhiteSpacePredicate whiteSpacePredicate)
{
checkStream();
while (m_position != EndOfFile && whiteSpacePredicate(*m_position))
while (!atEndOfFile() && whiteSpacePredicate(currentCharacter()))
advance();
}

View File

@ -17,7 +17,7 @@ namespace utils
//
////////////////////////////////////////////////////////////////////////////////////////////////////
const std::istream_iterator<Parser::CharacterType> Parser::EndOfFile = std::istream_iterator<Parser::CharacterType>();
const std::istreambuf_iterator<char> Parser::EndOfFile = std::istreambuf_iterator<char>();
////////////////////////////////////////////////////////////////////////////////////////////////////
@ -30,10 +30,9 @@ Parser::Parser(std::istream &istream)
{
std::setlocale(LC_NUMERIC, "C");
istream.exceptions(std::istream::badbit);
// Dont skip whitespace
istream >> std::noskipws;
istream.exceptions(std::istream::badbit);
checkStream();
}
@ -54,7 +53,7 @@ size_t Parser::column() const
////////////////////////////////////////////////////////////////////////////////////////////////////
Parser::CharacterType Parser::currentCharacter() const
char Parser::currentCharacter() const
{
checkStream();
@ -65,14 +64,14 @@ Parser::CharacterType Parser::currentCharacter() const
bool Parser::atEndOfFile() const
{
return m_position == EndOfFile;
return m_position.equal(EndOfFile);
}
////////////////////////////////////////////////////////////////////////////////////////////////////
void Parser::checkStream() const
{
if (m_position == EndOfFile)
if (atEndOfFile())
throw ParserException(m_row, m_column, "Reading past end of file");
if (m_istream.fail())
@ -85,7 +84,7 @@ void Parser::advance()
{
checkStream();
const auto character = *m_position;
const auto character = currentCharacter();
if (character == '\n')
{
@ -100,11 +99,11 @@ void Parser::advance()
////////////////////////////////////////////////////////////////////////////////////////////////////
bool Parser::advanceIf(CharacterType expectedCharacter)
bool Parser::advanceIf(char expectedCharacter)
{
checkStream();
if (*m_position != expectedCharacter)
if (currentCharacter() != expectedCharacter)
return false;
advance();
@ -129,7 +128,7 @@ void Parser::skipLine()
{
checkStream();
while (*m_position != '\n')
while (currentCharacter() != '\n')
advance();
advance();
@ -145,7 +144,7 @@ std::string Parser::getLine()
while (true)
{
const auto character = *m_position;
const auto character = currentCharacter();
advance();
@ -171,7 +170,7 @@ std::string Parser::parse<std::string>()
while (true)
{
const auto character = *m_position;
const auto character = currentCharacter();
if (std::isspace(character))
break;
@ -195,10 +194,10 @@ void Parser::expect<std::string>(const std::string &expectedValue)
std::for_each(expectedValue.cbegin(), expectedValue.cend(),
[&](const auto &expectedCharacter)
{
const auto character = *m_position;
const auto character = static_cast<char>(this->currentCharacter());
if (character != expectedCharacter)
throw ParserException(m_row, m_column, "Unexpected string, expected " + expectedValue);
throw ParserException(m_row, m_column, "Unexpected string, expected " + expectedValue + " (expected " + expectedCharacter + ", got " + character + ")");
this->advance();
});
@ -210,14 +209,14 @@ uint64_t Parser::parseIntegerBody()
{
checkStream();
if (!std::isdigit(*m_position))
if (!std::isdigit(currentCharacter()))
throw ParserException(m_row, m_column, "Could not parse integer value");
uint64_t value = 0;
while (m_position != std::istream_iterator<CharacterType>())
while (!atEndOfFile())
{
const auto character = *m_position;
const auto character = currentCharacter();
if (!std::isdigit(character))
break;
@ -252,7 +251,7 @@ uint64_t Parser::parse<uint64_t>()
{
skipWhiteSpace();
if (*m_position == '-')
if (currentCharacter() == '-')
throw ParserException(m_row, m_column, "Expected unsigned integer, got signed one");
return parseIntegerBody();