STR CollapseWhitespaceT(const STR& text,
bool trim_sequences_with_line_breaks)
{
STR result;
result.resize(text.size());
// 设置标志位为true假设已经在连续空白中, 这样可以移除开头的全部空白.
bool in_whitespace = true;
bool already_trimmed = true;
int chars_written = 0;
for(typename STR::const_iterator i=text.begin(); i!=text.end(); ++i)
{
if(IsWhitespace(*i))
{
if(!in_whitespace)
{
// 减少连续空白至一个空白.
in_whitespace = true;
result[chars_written++] = L' ';
}
if(trim_sequences_with_line_breaks && !already_trimmed &&
((*i=='\n') || (*i=='\r')))
{
// 包含回车换行的空白序列全部移除.
already_trimmed = true;
--chars_written;
}
}
else
{
// 非空白字符直接拷贝.
in_whitespace = false;
already_trimmed = false;
result[chars_written++] = *i;
}
}
if(in_whitespace && !already_trimmed)
{
// 忽略末尾的全部空白.
--chars_written;
}
result.resize(chars_written);
return result;
}
STR CollapseWhitespaceT(const STR& text,
bool trim_sequences_with_line_breaks) {
STR result;
result.resize(text.size());
// Set flags to pretend we're already in a trimmed whitespace sequence, so we
// will trim any leading whitespace.
bool in_whitespace = true;
bool already_trimmed = true;
int chars_written = 0;
for (typename STR::const_iterator i(text.begin()); i != text.end(); ++i) {
if (IsWhitespace(*i)) {
if (!in_whitespace) {
// Reduce all whitespace sequences to a single space.
in_whitespace = true;
result[chars_written++] = L' ';
}
if (trim_sequences_with_line_breaks && !already_trimmed &&
((*i == '\n') || (*i == '\r'))) {
// Whitespace sequences containing CR or LF are eliminated entirely.
already_trimmed = true;
--chars_written;
}
}
else {
// Non-whitespace chracters are copied straight across.
in_whitespace = false;
already_trimmed = false;
result[chars_written++] = *i;
}
}
if (in_whitespace && !already_trimmed) {
// Any trailing whitespace is eliminated.
--chars_written;
}
result.resize(chars_written);
return result;
}