core: add ZipPath encapsulating compressed zip files

this way you don't have to unpack it first and can work as if it's a 'virtual' directory

related: https://github.com/karlicoss/HPI/issues/20

my/core/kompress.py

@@ -1,6 +1,8 @@
 """
 Various helpers for compression
 """
+from __future__ import annotations
+
 import pathlib
 from pathlib import Path
 from typing import Union, IO
@@ -107,9 +109,44 @@ open = kopen # TODO deprecate
 
 
 # meh
+# TODO ideally switch to ZipPath or smth similar?
+# nothing else supports subpath properly anyway
 def kexists(path: PathIsh, subpath: str) -> bool:
     try:
         kopen(path, subpath)
         return True
     except Exception:
         return False
+
+
+import zipfile
+class ZipPath(zipfile.Path):
+    def absolute(self) -> ZipPath:
+        return ZipPath(Path(self.root.filename).absolute(), self.at)
+
+    def exists(self) -> bool:
+        if self.at == '':
+            # special case, the base class returns False in this case for some reason
+            return Path(self.root.filename).exists()
+        return super().exists()
+
+    def rglob(self, glob: str) -> Sequence[ZipPath]:
+        # note: not 100% sure about the correctness, but seem fine?
+        # Path.match() matches from the right, so need to
+        rpaths = [p for p in self.root.namelist() if p.startswith(self.at)]
+        rpaths = [p for p in rpaths if Path(p).match(glob)]
+        return [ZipPath(self.root, p) for p in rpaths]
+
+    def relative_to(self, other: ZipPath) -> Path:
+        assert self.root == other.root, (self.root, other.root)
+        return Path(self.at).relative_to(Path(other.at))
+
+    @property
+    def __class__(self):
+        return Path
+
+    def __eq__(self, other) -> bool:
+        # hmm, super class doesn't seem to treat as equals unless they are the same object
+        if not isinstance(other, ZipPath):
+            return False
+        return self.root.filename == other.root.filename and self.at == other.at