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gatech-csl / jes

The Jython Environment for Students allows students to write Jython programs that can manipulate pictures, sounds, and videos.
http://mediacomputation.org/
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Strange error messages fixed by restarting JES #102

Open rcbjork opened 7 years ago

rcbjork commented 7 years ago

We are using JES 5.02 on Mac lab computers. Yesterday several students ran into similar problems - JES would complain about a parameter problem with a call to a builtin function even though the call was correct. (Example: student was using repaint(some picture) and JES complained that repaint takes no parameters and one was supplied - even though the documentation says repaint requires one parameter. ) We ran into issue like this both with the number and the type of parameters - e.g. showPicture(some picture) complained that its parameter was not a picture even though it was. In each case we were able to solve the problem by quitting and then restarting JES - when - e.g. in the examples above it took the repaint call with a parameter as it should, and took the showPicture call with the same picture we had tried before. It appears something is being corrupted internally which is fixed by restarting.

mjguzdial commented 7 years ago

When I've seen problems like this in the past, I found that students had redefined the built-in functions (which is quite possible to do). If you create your own repaint() function without parameters, then that's the one that will get called, and you'll get exactly that error.

What makes me think about this error is that there is no builtin named showPicture(picture). There is a show(picture). If you're getting an error on showPicture(), then that's inside the user's code. That's not about a corrupted builtin.

From: rcbjork notifications@github.com Sent: Wednesday, August 31, 2016 12:44:58 PM To: gatech-csl/jes Subject: [gatech-csl/jes] Strange error messages fixed by restarting JES (#102)

We are using JES 5.02 on Mac lab computers. Yesterday several students ran into similar problems - JES would complain about a parameter problem with a call to a builtin function even though the call was correct. (Example: student was using repaint(some picture) and JES complained that repaint takes no parameters and one was supplied - even though the documentation says repaint requires one parameter. ) We ran into issue like this both with the number and the type of parameters - e.g. showPicture(some picture) complained that its parameter was not a picture even though it was. In each case we were able to solve the problem by quitting and then restarting JES - when - e.g. in the examples above it took the repaint call with a parameter as it should, and took the showPicture call with the same picture we had tried before. It appears something is being corrupted internally which is fixed by restarting.

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