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// Copyright (C) 2016 Jochen Becher
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0 WITH Qt-GPL-exception-1.0
#include "qstringparser.h"
// Possible Improvements
// %w: skip optional whitespaces in m_source
// more types: different int types, float, char, word, some character delimited string
// some Q Types: QColor (named, hex rgb)
// introduce public type ParseState which can be got from Parser and gives some info like error state, error index etc
QStringParser::QStringParser(const QString &source)
: m_source(source)
{
}
QStringParser::~QStringParser()
{
}
QStringParser::Parser QStringParser::parse(const QString &pattern)
{
return Parser(m_source, pattern);
}
QStringParser::Parser::Parser(const QString &source, const QString &pattern)
: m_source(source),
m_pattern(pattern)
{
}
QStringParser::Parser::~Parser()
{
evaluate();
qDeleteAll(m_nodes);
}
bool QStringParser::Parser::failed()
{
evaluate();
return m_evaluationFailed;
}
bool QStringParser::Parser::scan(int *i, int *index)
{
*i = 0;
int sign = 1;
while (*index < m_source.length() && m_source.at(*index).isSpace())
++(*index);
if (*index >= m_source.length())
return false;
if (m_source.at(*index) == QLatin1Char('+')) {
++(*index);
} else if (m_source.at(*index) == QLatin1Char('-')) {
sign = -1;
++(*index);
}
if (*index >= m_source.length() || !m_source.at(*index).isDigit())
return false;
while (*index < m_source.length() && m_source.at(*index).isDigit()) {
*i = *i * 10 + m_source.at(*index).digitValue();
++(*index);
}
*i *= sign;
return true;
}
bool QStringParser::Parser::scan(double *d, int *index)
{
int startIndex = *index;
// skip whitespaces
while (*index < m_source.length() && m_source.at(*index).isSpace())
++(*index);
if (*index >= m_source.length())
return false;
// sign
if (m_source.at(*index) == QLatin1Char('+'))
++(*index);
else if (m_source.at(*index) == QLatin1Char('-'))
++(*index);
// int
while (*index < m_source.length() && m_source.at(*index).isDigit())
++(*index);
// point
if (*index < m_source.length() && m_source.at(*index) == QLatin1Char('.'))
++(*index);
// int
while (*index < m_source.length() && m_source.at(*index).isDigit())
++(*index);
// exponent
if (*index < m_source.length() && m_source.at(*index).toLower() == QLatin1Char('e')) {
++(*index);
if (*index >= m_source.length())
return false;
// sign
if (m_source.at(*index) == QLatin1Char('+'))
++(*index);
else if (m_source.at(*index) == QLatin1Char('-'))
++(*index);
// int
while (*index < m_source.length() && m_source.at(*index).isDigit())
++(*index);
}
bool ok = false;
*d = m_source.mid(startIndex, *index - startIndex).toDouble(&ok);
return ok;
}
void QStringParser::Parser::evaluate()
{
if (!m_isEvaluated) {
m_isEvaluated = true;
m_evaluationFailed = false;
int p = 0;
int i = 0;
while (p < m_pattern.length()) {
if (m_pattern.at(p) == QLatin1Char('%')) {
++p;
// a % must be followed by a another char.
if (p >= m_pattern.length()) {
// syntax error in pattern
m_evaluationFailed = true;
return;
}
if (m_pattern.at(p) == QLatin1Char('%')) {
// two %% are handled like a simple % in m_source
++p;
if (i >= m_source.length() || m_source.at(i) != QLatin1Char('%')) {
m_evaluationFailed = true;
return;
}
++i;
} else if (m_pattern.at(p).isDigit()) {
// now extract a value matching the Nth node type
int N = 0;
while (p < m_pattern.length() && m_pattern.at(p).isDigit()) {
N = N * 10 + m_pattern.at(p).digitValue();
++p;
}
if (N < 1 || N > m_nodes.length()) {
// argument out of bounds in pattern
m_evaluationFailed = true;
return;
}
if (!m_nodes.at(N-1)->accept(*this, &i)) {
m_evaluationFailed = true;
return;
}
} else {
// any other % syntax is an error
m_evaluationFailed = true;
return;
}
} else {
if (m_pattern.at(p).isSpace()) {
++p;
// m_source must end or have at least one space
if (i < m_source.length() && !m_source.at(i).isSpace()) {
m_evaluationFailed = true;
return;
}
// skip spaces in m_pattern
while (p < m_pattern.length() && m_pattern.at(p).isSpace())
++p;
// skip spaces in m_source
while (i < m_source.length() && m_source.at(i).isSpace())
++i;
} else if (i >= m_source.length() || m_source.at(i) != m_pattern.at(p)) {
m_evaluationFailed = true;
return;
} else {
++p;
++i;
}
}
}
// m_source and m_pattern must both be scanned completely
if (i < m_source.length() || p < m_pattern.length()) {
m_evaluationFailed = true;
return;
}
}
}
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