exists: compatibility but keep speed

Author: scivision

+stdlib/exists.m

@@ -11,7 +11,15 @@
 
 function y = exists(fpath)
 
-y = isfile(fpath) || isfolder(fpath);
+try
+  y = isfile(fpath) || isfolder(fpath);
+catch e
+  if strcmp(e.identifier, 'MATLAB:UndefinedFunction')
+    y = exist(fpath,'file') == 2 || exist(fpath, 'dir') == 7;
+  else
+    rethrow(e)
+  end
+end
 
 end
 

test/TestExists.m

@@ -14,7 +14,7 @@ function test_dirs(tc)
 end
 
 
-methods (Test, TestTags={'R2017b'})
+methods (Test, TestTags={'R2017a'})
 
 function test_exists(tc, Ps)
 r = stdlib.exists(Ps{1});

test/TestFileImpure.m

@@ -43,7 +43,9 @@ function test_makedir(tc)
 d = 'test_makedir.dir';
 stdlib.makedir(d)
 
-if stdlib.matlabOlderThan('R2018a')
+if stdlib.matlabOlderThan('R2017b')
+  tc.assertTrue(exist(d, 'dir') == 7)
+elseif stdlib.matlabOlderThan('R2018a')
   tc.assertTrue(isfolder(d))
 else
   tc.verifyThat(d, matlab.unittest.constraints.IsFolder)

test/TestFilePure.m

@@ -1,5 +1,5 @@
 classdef (SharedTestFixtures={ matlab.unittest.fixtures.PathFixture(fileparts(fileparts(mfilename('fullpath'))))}, ...
-          TestTags = {'R2017b', 'pure'}) ...
+          TestTags = {'R2017a', 'pure'}) ...
     TestFilePure < matlab.unittest.TestCase
 
 

test/TestFilename.m

@@ -1,5 +1,5 @@
 classdef (SharedTestFixtures={ matlab.unittest.fixtures.PathFixture(fileparts(fileparts(mfilename('fullpath'))))}, ...
-          TestTags = {'R2017b', 'pure'}) ...
+          TestTags = {'R2017a', 'pure'}) ...
     TestFilename < matlab.unittest.TestCase
 
 properties (TestParameter)

test/TestIsExe.m

@@ -1,5 +1,5 @@
 classdef (SharedTestFixtures={ matlab.unittest.fixtures.PathFixture(fileparts(fileparts(mfilename('fullpath'))))}, ...
-          TestTags = {'R2017b', 'pure'}) ...
+          TestTags = {'R2017a', 'pure'}) ...
     TestIsExe < matlab.unittest.TestCase
 
 properties (TestParameter)

test/TestWhich.m

@@ -8,7 +8,7 @@
 end
 
 
-methods (Test, TestTags = {'R2017b'})
+methods (Test, TestTags = {'R2017a'})
 
 function test_which_name(tc)
 
@@ -27,7 +27,6 @@ function test_which_name(tc)
 for n = names
   exe = stdlib.which(n);
   tc.verifyNotEmpty(exe, "Executable not found: " + n)
-  tc.verifyTrue(isfile(exe), "Executable is not a file: " + n)
   tc.verifyTrue(stdlib.is_exe(exe), "Executable is not executable: " + n)
 end
 
@@ -41,7 +40,6 @@ function test_which_absolute(tc, mexe)
   r = [r, '.exe'];
 end
 
-tc.assumeTrue(isfile(r))
 tc.assumeTrue(stdlib.is_exe(r))
 
 tc.verifyGreaterThan(strlength(stdlib.which(r)), 0, "Expected which(" + r + " ) to find " + r)
@@ -50,7 +48,7 @@ function test_which_absolute(tc, mexe)
 
 
 function test_which_onepath(tc)
-tc.verifyNotEmpty(stdlib.which("matlab", fullfile(matlabroot, 'bin')), ...
+tc.verifyNotEmpty(stdlib.which('matlab', fullfile(matlabroot, 'bin')), ...
     "Matlab not found by which() given specific path=")
 end
 
@@ -59,7 +57,7 @@ function test_which_multipath(tc)
 paths = split(string(getenv('PATH')), pathsep);
 paths(end+1) = fullfile(matlabroot, 'bin');
 
-tc.verifyNotEmpty(stdlib.which("matlab", paths), "Matlab not found by which()")
+tc.verifyNotEmpty(stdlib.which('matlab', paths), "Matlab not found by which()")
 end
 
 end