relative_to: add native method

Author: scivision

+stdlib/+native/relative_to.m

@@ -0,0 +1,35 @@
+%% NATIVE.RELATIVE_TO find relative path to target from base
+
+function rel = relative_to(base, target)
+
+% matlab.io.internal.filesystem.relativepath only works on Windows (!) and only
+% then with / filesep.
+
+if stdlib.strempty(base) || stdlib.strempty(target)
+  rel = "";
+  return
+end
+
+tp = strsplit(fullfile(target), filesep);
+bp = strsplit(fullfile(base), filesep);
+
+% Find the common base portion
+n = 0;
+while n < length(tp) && n < length(bp) && strcmp(tp{n+1}, bp{n+1})
+  n = n + 1;
+end
+
+% Number of '..' needed
+numUp = length(bp) - n;
+
+relParts = [repmat({'..'}, 1, numUp), tp(n+1:end)];
+
+rel = fullfile(relParts{:});
+
+if isempty(rel)
+  rel = '.';
+end
+
+rel = string(rel);
+
+end

+stdlib/posix.m

@@ -4,9 +4,6 @@
 %
 
 function r = posix(p)
-arguments
-  p {mustBeTextScalar}
-end
 
 if ispc
   r = strrep(p, '\', '/');

+stdlib/relative_to.m

@@ -16,18 +16,10 @@
   other {mustBeTextScalar}
 end
 
-if (stdlib.strempty(base) && stdlib.strempty(other)) || ...
-   (stdlib.is_absolute(base) ~= stdlib.is_absolute(other))
-  rel = "";
-  return
-end
-
 if stdlib.has_python()
   rel = stdlib.python.relative_to(base, other);
-elseif stdlib.dotnet_api() >= 5
-  rel = stdlib.dotnet.relative_to(base, other);
 else
-  rel = stdlib.sys.relative_to(base, other);
+  rel = stdlib.native.relative_to(base, other);
 end
 
 end

+stdlib/+dotnet/device.m renamed to example/dotnet/device.m

@@ -1,7 +1,11 @@
 %% DOTNET.RELATIVE_TO find the relative path to other from base
+%
+% not normally used because it's overly complex
 
 function rel = relative_to(base, other)
 
+assert(stdlib.dotnet_api() >= 5)
+
 if stdlib.strempty(other)
   rel = base;
   return

+stdlib/+dotnet/relative_to.m renamed to example/dotnet/relative_to.m

@@ -1,3 +1,7 @@
+%% SYS.RELATIVE_TO get relative path to other from base
+%
+% this works but is slow
+
 function r = relative_to(base, other)
 
 r = "";
@@ -22,7 +26,7 @@
 r = string(strip(r));
 
 if ispc()
-  r = fullfile(stdlib.normalize(r));
+  r = stdlib.normalize(r);
 end
 
 end

+stdlib/+sys/relative_to.m renamed to example/sys/relative_to.m

@@ -7,7 +7,7 @@
 properties (TestParameter)
 pr = init_rel()
 pp = init_prox()
-rel_fun = {@stdlib.relative_to, @stdlib.sys.relative_to, @stdlib.dotnet.relative_to, @stdlib.python.relative_to}
+rel_fun = {@stdlib.relative_to, @stdlib.native.relative_to, @stdlib.python.relative_to}
 end
 
 methods(TestClassSetup)
@@ -44,8 +44,7 @@ function test_proximate_to(tc, pp)
 
 p = {{"", "", ""}, ...
 {fileparts(pwd()), pwd(), "test"}, ...
-{root, fullfile(root, "test", mfilename() + ".m"), fullfile("test", mfilename + ".m")}, ...
-{"/", "/", "."}, ...
+{root, fullfile(root, "test", mfilename() + ".m"), fullfile("test", mfilename + ".m")}
 };
 % NOTE: ".." in relative_to(base) is ambiguous including for python.pathlib, C++ <filesystem>, etc.
 
@@ -79,6 +78,7 @@ function test_proximate_to(tc, pp)
 else
 
 p = [p, {
+{"/", "/", "."}, ...
 {"/dev/null", "/dev/null", "."}, ...
 }];
 end

test/TestRelative.m

@@ -16,10 +16,6 @@ function is_capable(tc, f)
     tc.assumeTrue(ispc(), "Windows only function")
   end
 
-  if endsWith(n, "relative_to")
-    tc.assumeGreaterThanOrEqual(dapi, 5)
-  end
-
   if endsWith(n, ["create_symlink", "ram_total", "read_symlink"])
     tc.assumeGreaterThanOrEqual(dapi, 6);
   end
@@ -50,10 +46,7 @@ function is_capable(tc, f)
    end
 
 elseif contains(n, ".sys.")
-
-  if ismac() && endsWith(n, "relative_to")
-    tc.assumeNotEmpty(stdlib.which("greadlink"), "brew install coreutils")
-  end
+ % pass
 
 elseif contains(n, ".native.")