parent: efficiency

Author: scivision

+stdlib/+java/parent.m

@@ -2,11 +2,12 @@
 
 p = java.io.File(pth).getParent();
 if isempty(p)
-  rn = stdlib.root_name(pth);
-  if ispc() && ~stdlib.strempty(pth) && ~stdlib.strempty(rn) && startsWith(pth, rn)
-    p = strcat(rn, filesep);
-  else
-    p = ".";
+  p = ".";
+  if ispc()
+    rn = stdlib.root_name(pth);
+    if strlength(pth) && strlength(rn) && startsWith(pth, rn)
+      p = strcat(rn, filesep);
+    end
   end
 else
   p = string(p);

+stdlib/+native/parent.m

@@ -3,15 +3,9 @@
   pth string
 end
 
-f = fullfile(pth);
+p = fileparts(stdlib.drop_slash(pth));
 
-i = endsWith(f, ["/", filesep]) & ~strcmp(f, stdlib.root(f));
-
-f(i) = extractBefore(f(i), strlength(f(i)));
-
-p = fileparts(f);
-
-i = stdlib.strempty(p);
+i = ~strlength(p);
 p(i) = ".";
 
 % the ~all(i) is for Windows Matlab < R2025a

+stdlib/+python/parent.m

@@ -1,13 +1,14 @@
-function p = parent(pth)
+function par = parent(pth)
 
 try
-  p = string(py.str(py.pathlib.Path(pth).parent));
-  if ispc() && p == stdlib.root_name(pth)
-    p = p + filesep;
+  op = py.pathlib.Path(pth);
+  p = op.parent;
+  par = string(py.str(p));  % 2x faster than string(op.parents(1))
+  if ispc() && p == op.drive
+    par = par + filesep;
   end
 catch e
-  p = "";
-  warning(e.identifier, "parent(%s) failed: %s", pth, e.message)
+  par = "";
 end
 
 end

+stdlib/parent.m

@@ -16,12 +16,12 @@
   backend (1,:) string = ["java", "python", "native"]
 end
 
-if isscalar(file)
-  [fun, b] = hbackend(backend, "parent");
+[fun, b] = hbackend(backend, "parent");
+
+if isscalar(file) || b == "native"
   par = fun(file);
 else
-  b = "native";
-  par = stdlib.native.parent(file);
+  par = arrayfun(fun, file);
 end
 
 end