root* handle more effeciently

Author: scivision

+stdlib/root_dir.m

@@ -13,15 +13,14 @@
   p {mustBeTextScalar}
 end
 
-c = char(p);
 r = '';
 
-if isempty(c)
-  % pass
-elseif ismember(c(1), {'/', filesep})
-  r = c(1);
+if stdlib.strempty(p)
+  r = p;
+elseif ismember(p(1), {'/', filesep})
+  r = extractBefore(p, 2);
 elseif ispc()
-  m = regexp(c, '^[A-Za-z]:([\\/])', 'tokens', 'once');
+  m = regexp(p, '^[A-Za-z]:([\\/])', 'tokens', 'once');
   if ~isempty(m)
     r = m{1};
   end
@@ -32,10 +31,3 @@
 end
 
 end
-
-%!test
-%! if ispc()
-%!   assert(strcmp(strcmp.root_dir('c:/hi'), '/'))
-%! else
-%!   assert(strcmp(stdlib.root_dir('/a/.bc'), '/'))
-%! end

+stdlib/root_name.m

@@ -10,16 +10,10 @@
   p {mustBeTextScalar}
 end
 
-c = char(p);
-
-if ispc() && ~isempty(regexp(c, '^[A-Za-z]:', 'once'))
-  r = c(1:2);
+if ispc() && ~isempty(regexp(p, '^[A-Za-z]:', 'once'))
+  r = extractBefore(p, 3);
 else
   r = '';
 end
 
-if isstring(p)
-  r = string(r);
-end
-
 end