Noodlle TroubleShooting: Error Messages, Documented Bugs, etc

• {Error : "Parse : Unknown character: 0x29'."}
• {Error : "Parse : Unterminated list--too few ')')"}
• {Error : "Unbound variable x"}
• {Error : "Define : Requires variable and value, or (variable type) and value."}
• {Error : "Apply : Too many arguments in function {Method : cons ((P {Class <object>(1)})(Q {Class <object>(1)}))}"}
• {Error : "Apply : Too few arguments in function {Method : cons ((P {Class <object>(1)})(Q {Class <object>(1)}))}"}
• {Error : "Object #f failed type constraint <object>"}
• Ctrl-E does not work
• Flashing in the "main" window
• Other Bugs and  Tips (you really should read them)

• Error message:

  {Error : "Parse : Unknown character: 0x29'."}

  This means that you probably have an extra right paren ')' somewhere in the code just evaluated. Count your parens, and try again. If this doesn't help, save your work and restart Netscape. I have seen this error appear when the parens do match, and the only way to fix this is to restart the applet. Of course, if restarting the applet doesn't help, then you should count your parentheses again. =P

• Error message:

  {Error : "Parse : Unterminated list--too few ')')"}

  This means that you are missing a right paren ')' somewhere. Check your parens. The only case where you will erroneously get this message is if you have a minus sign, '-' immediately followed by a right paren, ')' - for example, ((method (x) x) -) or (singleton '-). This is due to a bug in parsing. You will need to put a space between the minus sign and the paren.

• Error message:

  {Error : "Unbound variable x"}

  This means that a variable called 'x' has been referenced somewhere in the code, and NOODLLE has no clue what x is supposed to be. Either it needs to be defined, or it needs to be bound (in a bind). Or maybe you just need to reference the right variable. Whatever it is, there is something wrong in your code.

• Error message:

  {Error : "Define : Requires variable and value, or (variable type) and value."}

  This is mostly pretty self-explanatory. Make sure that the value is a single expression, and not a body. It is possible that there is an extra paren somewhere earlier in the code, closing off the expression before you really want to.

• Error message:

  {Error : "Apply : Too many arguments in function {Method : cons ((P {Class <object>(1)})(Q {Class <object>(1)}))}"}

  One of your calls to the function specified (in this case, cons) has too many arguments. Just look for all calls to the function and find the error.

• Error message:

  {Error : "Apply : Too few arguments in function {Method : cons ((P {Class <object>(1)})(Q {Class <object>(1)}))}"}

  Same as above, except there are too few arguments.

• Error:

  Ctrl-E does not work.

  In the middle of a (read), or while anything is currently being evaluated, Ctrl-E will not work, and you will have to use the EVAL button instead.

• Flashing will occur in the "main" window (if it doesn't, consider yourself lucky)

  To make the text reappear after flashing, you just have to do something that will make Java call repaint: minimize, cover, or highlight. If you highlight while the game is printing text, it will replace everything you highlight. Be careful to highlight the text only when the screen has stopped flashing.

• If you get an error message saying something like

  {Error : "Object #f failed type constraint <object>"},

  then you must restart Noodlle by pressing Shift-"Reload". If it does not help, restart Netscape.

• Clear the window every so often, because NOODLLE can only handle a limited amount of text at a time.
• For some reason, sometimes the stuff you eval after clearing NOODLLE goes into a black hole, and nothing happens. Just try again.
• Use the frame inspector to track your bugs! For all functions, the bottom frame will list the name of the function running when the error occurred, and the top frame gives you the parameters. The middle frame lists the name of the environment it is currently being evaluated in. You can click on other functions and environments to get the lists of their parameters or definitions.
• the edit areas both skip to the end of the text whenever enter is pressed
• <vector>s containing one object print out as empty vectors
• creating large vectors tends to be slow. This is a java thing.
• truncate will loop indefinitely if given an integer
• Generic functions are being flaky, if you encounter a problem with them accepting classes you create, see the course staff. In general, though, they work.

Sometimes NOODLLE seems to be running, but it is rejecting obviously correct code. In this case, try pressing Shift-"Reload button". If it does not help, you should restart Netscape after clearing both the memory and the disk cache. This clears out all instances of NOODLLE from memory. If it does not help, try it on another computer if possible.

If all else fails, bring it into consulting, and we can track down your bug or tell you if the problem is NOODLLE. If you have a short description, how one can reproduce your problem, post it to cornell.class.cs212 newsgroup.

Do NOT assume that the error you are getting is NOODLLEs fault! If restarting Netscape and trying another computer does not get rid of your problem, then it is more likely that there is a bug in your code.

If this is an emergency, you may also e-mail Melissa Ho (for interpreter related problems)

Last update:  01/19/00 11:36 PM