is_readable: java optional, much faster

Author: scivision

+stdlib/+java/is_readable.m

@@ -0,0 +1,5 @@
+function y = is_readable(p)
+
+y = javaObject("java.io.File", p).canRead();
+
+end

+stdlib/private/file_attributes_legacy.m renamed to +stdlib/+native/file_attributes.m

@@ -1,4 +1,4 @@
-function a = file_attributes_legacy(p)
+function a = file_attributes(p)
 arguments
   p {mustBeTextScalar}
 end

+stdlib/+native/is_readable.m

@@ -0,0 +1,24 @@
+function y = is_readable(p)
+
+y = false;
+
+if ~stdlib.exists(p), return, end
+
+if ~isMATLABReleaseOlderThan('R2025a')
+
+  props = "Readable";
+  if isunix
+    props = [props, "GroupRead", "OtherRead"];
+  end
+
+  t = getPermissions(filePermissions(p), props);
+  y = t.Readable;
+
+else
+
+  a = stdlib.native.file_attributes(p);
+  y = a.UserRead || a.GroupRead || a.OtherRead;
+
+end
+
+end

+stdlib/get_permissions.m

@@ -20,7 +20,7 @@
   end
   return
 else
-  v = file_attributes_legacy(f);
+  v = stdlib.native.file_attributes(f);
 end
 
 p = perm2char(v, f);

+stdlib/is_exe.m

@@ -31,7 +31,7 @@
 
 else
 
-  a = file_attributes_legacy(p);
+  a = stdlib.native.file_attributes(p);
   ok = a.UserExecute || a.GroupExecute || a.OtherExecute;
 
 end

+stdlib/is_readable.m

@@ -5,32 +5,16 @@
 %% Outputs
 % ok: logical array of the same size as p, true if file is readable
 
-function ok = is_readable(p)
+function y = is_readable(p)
 arguments
-  p string
+  p {mustBeTextScalar}
 end
 
-ok(size(p)) = false;
-
-i = stdlib.exists(p);
-
-if ~any(i), return, end
-
-if ~isMATLABReleaseOlderThan('R2025a')
-
-  props = "Readable";
-  if isunix
-    props = [props, "GroupRead", "OtherRead"];
-  end
-
-  t = getPermissions(filePermissions(p(i)), props);
-  ok(i) = any(t{:,:}, 2);
-
+if stdlib.has_java()
+  y = stdlib.java.is_readable(p);
 else
-
-  a = file_attributes_legacy(p);
-  ok = a.UserRead || a.GroupRead || a.OtherRead;
-
+  y = stdlib.native.is_readable(p);
 end
 
+
 end

+stdlib/is_writable.m

@@ -27,7 +27,7 @@
   ok(i) = any(t{:,:}, 2);
 
 else
-  a = file_attributes_legacy(p);
+  a = stdlib.native.file_attributes(p);
   ok = a.UserWrite || a.GroupWrite || a.OtherWrite;
 end
 

test/TestExists.m

@@ -8,6 +8,7 @@
 {tempname(), false}
 }
 % on CI matlabroot can be writable!
+isr_fun = {@stdlib.is_readable, @stdlib.java.is_readable, @stdlib.native.is_readable}
 end
 
 methods(TestClassSetup)
@@ -25,8 +26,10 @@ function test_exists(tc, Ps)
 end
 
 
-function test_is_readable(tc, Ps)
-ok = stdlib.is_readable(Ps{1});
+function test_is_readable(tc, Ps, isr_fun)
+is_capable(tc, isr_fun)
+
+ok = isr_fun(Ps{1});
 tc.verifyEqual(ok, Ps{2}, Ps{1})
 end