emacsrunregion.m:

Check input file more rigoruously.  If not on path, make it be on path
before evaluating.
Implement version that uses 'eval'.  Leave structure in place for
calling a ML utility for doing eval of a region of a file.

toolbox/emacsrunregion.m

@@ -1,28 +1,49 @@
 function emacsrunregion(file, startchar, endchar)
 % Run code from FILE between STARTCHAR and ENDCHAR.
 % Uses internal Editor API to enable support of local functions and breakpoints.
-    
-    fullFileName = which(file); % get full expansion
 
-    if ~exist(fullFileName,'file')
-        error('You must save your region into an accessible file.');
+    if exist(file,'file')
+        fullFileName = file;
+    else
+        error('You must save your region into a file accessible by MATLAB process.');
     end
+
+    % Now figure out if shortFileName is on the path.  We can use a special eval
+    % if it is.
+    [ fullFilePath, shortFileName ] = fileparts(fullFileName);
+    revlookup = which(shortFileName);
+    if ~isempty(revlookup) && strcmp(revlookup, fullFileName)
+        onpath = true;
+    else
+        onpath = false;
+    end
+
+    % Of not on the path, temporarilly switch to that directory.
+    if ~onpath
+        oldpath = pwd;
+        cd(fullFilePath);
+    end
+    
+    if true % TODO remove true eventually
         
-    [ fullFilePath, shortFileName ] = fileparts(fullFileName);  %#ok  % Get the file parts
-    
-    fullFileText = fileread(fullFileName); % Get the text
+        % When other options aren't a vailable, use eval on extracted text. 
+        % disp('Evaluating with eval');
+        
+        TXT = fileread(fullFileName);
+        ETXT = TXT(startchar:endchar);
+        
+        eval(ETXT);
 
-    % TODO - find out if this is available.  If it isn't, we can extract the text and
-    % then use evalin or something.
+    else
+        % Newer versions of MATLAB with Live Editor can call into the evaluator.
+        % disp('Evaluating with LXE');
+        
+        % TODO - get permission for using internal API for running regions of a file.
+        % builtin('_xxxx', 'base', shortFileName, startchar, endchar-startchar)
+    end
     
-    % Call into the evaluator.
-    feature('DisablePrelineEvents', true);
     
-    % TODO - Info I got says fullFilePath, not the shortFileName for
-    % below.  Need to try in more versions of MATLAB.
-    
-    builtin('_LiveEvaluate', 'caller', shortFileName, startchar, endchar-startchar, [], [], [], [], ...
-            true, fullFileText)
-    feature('DisablePrelineEvents', false);
-
+    if ~onpath % Return to previous directory
+        cd(oldpath);
+    end
 end