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|
//===- Path.inc -----------------------------------------------------------===//
//
// The SkyPat Team
//
// This file is distributed under the New BSD License.
// See LICENSE for details.
//
//===----------------------------------------------------------------------===//
#include <string>
#include <stack>
namespace skypat {
const char Path::separator = '/';
const char Path::preferred_separator = '/';
const Path::StringType Path::separator_str = Path::StringType("/");
namespace sys {
// return the last charactor being handled.
size_t canonicalize(std::string& pathname)
{
// Variable Index //
// SepTable - stack of result separators
// LR(1) Algorithm //
// traverse pPathName
// if we meet '//', '///', '////', ...
// -> ignore it
// -> push current into stack
// -> jump to the next not '/'
// if we meet '/./'
// -> ignore
// -> jump to the next not '/'
// if we meet '/../'
// -> pop previous position of '/' P
// -> erase P+1 to now
// if we meet other else
// -> go go go
// if we meet '/.../', '/..../', ... -> illegal
if (pathname.empty())
return 0;
size_t handler = 0;
std::stack<size_t> slash_stack;
slash_stack.push(-1);
while (handler < pathname.size()) {
if (Path::separator == pathname[handler]) { // handler = 1st '/'
size_t next = handler + 1;
if (next >= pathname.size())
return handler;
switch(pathname[next]) { // next = handler + 1;
case Path::separator: { // '//'
while (next < pathname.size() && Path::separator == pathname[next])
++next;
// next is the last not '/'
pathname.erase(handler, next - handler - 1);
// handler is the first '/'
slash_stack.push(handler);
break;
}
case '.': { // '/.'
++next; // next = handler + 2
if (next >= pathname.size()) // '/.'
return handler;
switch (pathname[next]) {
case Path::separator: { // '/./'
pathname.erase(handler, 2);
break;
}
case '.': { // '/..'
++next; // next = handler + 3;
if (next >= pathname.size()) // '/..?'
return handler;
switch(pathname[next]) {
case Path::separator: { // '/../'
handler = slash_stack.top();
slash_stack.pop();
pathname.erase(handler+1, next-handler);
if (static_cast<size_t>(-1) == handler) {
slash_stack.push(-1);
handler = pathname.find_first_of(Path::separator, handler);
}
break;
}
case '.': { // '/...', illegal
return handler;
break;
}
default : { // '/..a'
slash_stack.push(handler);
handler = pathname.find_first_of(Path::separator, handler+3);
break;
}
}
break;
}
default : { // '/.a'
slash_stack.push(handler);
handler = pathname.find_first_of(Path::separator, handler+2);
break;
}
}
break;
}
default : { // '/a
slash_stack.push(handler);
handler = pathname.find_first_of(Path::separator, handler+1);
break;
}
}
}
else {
handler = pathname.find_first_of(Path::separator, handler);
}
}
return handler;
}
/// Checks if \ref pValue is the separator of the path in the system.
bool is_separator(char value)
{
return (value == Path::separator);
}
} // namespace of sys
} // namespace of skypat
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