add io::path.normalized()

src/io/path.cpp

@@ -1,6 +1,6 @@
 #include "path.hpp"
 
-#include <stdexcept>
+#include <stack>
 
 using namespace io;
 
@@ -9,3 +9,30 @@ void path::checkValid() const {
         throw std::runtime_error("path entry point is not specified: " + str);
     }
 }
+
+path path::normalized() const {
+    io::path path = pathPart();
+
+    std::stack<std::string> parts;
+    do {
+        parts.push(path.name());
+        path.str = path.parent().string();
+    } while (!path.empty());
+
+    while (!parts.empty()) {
+        const std::string part = parts.top();
+        parts.pop();
+        if (part == ".") {
+            continue;
+        }
+        if (part == "..") {
+            throw access_error("entry point reached");
+        }
+
+        path = path / part;
+    }
+    if (path.colonPos != std::string::npos) {
+        path = path.entryPoint() + ":" + path.string();
+    }
+    return path;
+}