Fix #95

nimporter/nexporter.py

@@ -256,22 +256,17 @@ def compile_extensions_to_c(platforms: List[str], root: Path) -> None:
                     prevent_win32_max_path_length_error(out_dir)
     return
 
-
-def _is_valid_identifier(string: str) -> Union[Match[str], None, bool]:
-        import re
-        match = re.search('^[A-Za-z_][A-Z-a-z0-9_\\-]*', string)
-        return match and len(match.string) == len(string)
-
-
 def _is_semver(string: str) -> bool:
+    import re
     try:
-        lib_name, lib_version = string.rsplit('-', maxsplit=1)
-        assert _is_valid_identifier(lib_name)
+        match = re.search(
+            r'(\w+)-(?<major>\d+)\.(?<minor>\d+)\.(?<patch>\d+)(-?.+)'
+        )
 
-        major, minor, patch = lib_version.split('.')
-        assert major.isdigit()
-        assert minor.isdigit()
-        assert patch.isdigit()
+        groups = match.groupdict()
+        assert groups['major'].isdigit()
+        assert groups['minor'].isdigit()
+        assert groups['patch'].isdigit()
 
         return True
     except:
@@ -314,6 +309,13 @@ def prevent_win32_max_path_length_error(path: Path) -> None:
                         mod_name = '@'.join(segments[index:])
                         break
 
+                # Local imports which don't include a semver
+                else:
+                    mod_name = item.name.replace('@m', '')
+
             new_name = ic(f'NIMPORTER@{mod_name}')
+            assert not item.with_name(new_name).exists(), (
+                f"Bug with @ replacements: {new_name} shouldn't already exist"
+            )
             item.replace(item.with_name(new_name))
     return