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Syntax

CATCH "ERROR

Explanation

ERROR is the error object used by error handling mechanism. See also CATCH and THROW.

If you catch an error, the system variable ERROR contains a short word describing the error which occured:

"NODE Out of list space.
"ATOM Out of atom space.
"MEM Out of memory.
"STCK Too many recursive procedure calls.
"AFN Ambiguous filename not allowed.
"FILE File xxxx not found.
"IO Input/output (I/O) error.
"OPEN File stream xxxx not open.
"STRU No more file structures for OPEN or CREATE.
"USED xxxx is already in use. Try a different name.
"HASH Bad number syntax.
"OUT You don't say what to do with the output of xxxx.
"INP The procedure xxxx does not like yyyy as input.
"VAL xxxx is not a valid input for yyyy.
"PROC xxxx is not a Logo procedure.
"NAME xxxx is not a Logo name.
"MORE xxxx needs more input(s).
"CTCH Can't find catch for xxxx
"BUFF Unable to create buffer for picture.
"MATH Math overflow.
"DIV0 Division by zero.
"INT Internal error: xxxx
"MOVE Attempt to move turtle nnnn outside the fence.
"WIN Turtle(s) nnnn must be inside window.
"DOT Attempt to draw a dot outside the screen.
"PCX Unable to load picture xxxx
"TELL Cannot TELL turtle xxxx; there are only nnnn turtles...
"PRN No printer defined.
"RDY Printer not ready.
"CLIP Clipboard error.
"TICK Cannot create timer.
"VER Service not available.
"MCI MCI command interface error.

Note that the variable ERROR always contains the last error which occured, unless you explicitly assign a different value to it.

Example

? HELLO

HELLO is not a Logo procedure.

? CATCH "ERROR [HELLO]

? :ERROR

Result: PROC

?

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