relative_to: native only as it's 5x faster than python

Author: scivision

+stdlib/+native/relative_to.m

@@ -3,19 +3,16 @@
 %%% Inputs
 % * base: directory to which the other path should be relative
 % * other: path to be made relative
-% * backend: backend to use
 %%% Outputs
 % * rel: relative path from base to other
-% * b: backend used
 
-function [rel, b] = proximate_to(base, other, backend)
+function rel = proximate_to(base, other)
 arguments
   base (1,1) string
   other (1,1) string
-  backend (1,:) string = ["python", "native"]
 end
 
-[rel, b] = stdlib.relative_to(base, other, backend);
+rel = stdlib.relative_to(base, other);
 if stdlib.strempty(rel)
   rel = other;
 end

+stdlib/+python/relative_to.m

@@ -1,26 +1,44 @@
-%% RELATIVE_TO relative path to base
+%% RELATIVE_TO relative path to target from base
 %
 %%% Inputs
 % * base: directory to which the other path should be relative
-% * other: path to be made relative
-% * backend: backend to use
+% * target: path to be made relative
 %%% Outputs
-% * rel: relative path from base to other
-% * b: backend used
+% * rel: relative path from base to target
 %
 % Note: Java Path.relativize has an algorithm so different that we choose not to use it.
-% javaPathObject(base).relativize(javaPathObject(other))
+% javaPathObject(base).relativize(javaPathObject(target))
 % https://docs.oracle.com/javase/8/docs/api/java/nio/file/Path.html#relativize-java.nio.file.Path-
 
-function [rel, b] = relative_to(base, other, backend)
+function rel = relative_to(base, target)
 arguments
   base (1,1) string
-  other (1,1) string
-  backend (1,:) string = ["native", "python"]
+  target (1,1) string
 end
 
-o = stdlib.Backend(mfilename(), backend);
-rel = o.func(base, other);
-b = o.backend;
+% matlab.io.internal.filesystem.relativepath only works on Windows (!) and only
+% then with / filesep.
+
+if stdlib.strempty(base) || stdlib.strempty(target)
+  rel = "";
+  return
+end
+
+fs = ["/", filesep];
+
+tp = split(fullfile(target), fs);
+bp = split(fullfile(base), fs);
+
+% 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
+
+rel = join(tp(n+1:end), filesep);
+
+if stdlib.strempty(rel)
+  rel = ".";
+end
 
 end

+stdlib/proximate_to.m

@@ -0,0 +1,19 @@
+function rel = relative_to(base, target)
+arguments
+  base (1,1) string
+  target (1,1) string
+end
+
+rel = "";
+
+if stdlib.strempty(base) || stdlib.strempty(target)
+  return
+end
+
+try
+  rel = string(py.str(py.pathlib.Path(target).relative_to(base)));
+catch e
+  pythonException(e)
+end
+
+end

+stdlib/relative_to.m

@@ -0,0 +1,26 @@
+classdef (SharedTestFixtures={ matlab.unittest.fixtures.PathFixture(fileparts(fileparts(mfilename('fullpath'))))}) ...
+    BenchmarkRelativeTo < matlab.perftest.TestCase
+
+properties
+in = [pwd(), pwd() + "/a"]
+ref = "a"
+end
+
+properties (TestParameter)
+fun = {@stdlib.relative_to, @stdlib.python.relative_to}
+end
+
+
+methods (Test)
+
+function bench_main(tc, fun)
+while tc.keepMeasuring()
+  r = fun(tc.in(1), tc.in(2));
+end
+
+tc.verifyEqual(r, tc.ref)
+end
+
+end
+
+end

example/+python/relative_to.m

@@ -0,0 +1,16 @@
+function BenchmarkRelativeToRun()
+tname = "BenchmarkRelativeTo";
+
+%% Exist, same
+r.same = run_bench(tname + "/bench_main");
+s.exist = sortrows(sampleSummary(r.same), "Median");
+disp(s.exist(:, ["Name", "SampleSize", "Mean", "Median"]))
+
+end
+
+
+function result = run_bench(name)
+suite = testsuite(name);
+exp = matlab.perftest.TimeExperiment.limitingSamplingError(RelativeMarginOfError=0.1);
+result = exp.run(suite);
+end

example/BenchmarkRelativeTo.m

@@ -5,7 +5,6 @@
 
 properties (TestParameter)
 pr
-backend
 end
 
 
@@ -57,23 +56,19 @@
 }];
 end
 end
-
-function backend = setupBackends()
-backend = init_backend("relative_to");
-end
 end
 
 
 methods (Test)
 
-function test_relative_to(tc, pr, backend)
-r = stdlib.relative_to(pr{1}, pr{2}, backend);
+function test_relative_to(tc, pr)
+r = stdlib.relative_to(pr{1}, pr{2});
 
 tc.verifyEqual(r, pr{3}, "relative_to(" + pr{1} + "," + pr{2}+")")
 end
 
-function test_proximate_to(tc, pr, backend)
-r = stdlib.proximate_to(pr{1}, pr{2}, backend);
+function test_proximate_to(tc, pr)
+r = stdlib.proximate_to(pr{1}, pr{2});
 
 tc.verifyEqual(r, pr{3}, "proximate_to(" + pr{1} + ", " + pr{2}+")")
 end