CxObjError

obtain a commodity object's accumulated error. (V36)

When a function acting on an object fails, it records the failure in the object. This function returns the accumulated error value. The values are represented by flag bits defined in <libraries/commodities.h>. Several errors may be recorded by multiple bits in 'error'.

The currently defined errors are:

COERR_ISNULL

The value of parameter 'co' was in fact NULL. This error means "the problem with the object you inquire about is that it failed to be created."

COERR_NULLATTACH

Using the commodities' list manipulation functions, an attempt was made to add a NULL object to the list belonging to 'co'. This allows a line of code as follows to exist in an error-tolerant program:

AttachCxObj(filter,CxSender(myport,MY_ID));

COERR_BADFILTER

The most recent filter specification for a filter object was faulty. This happens if no sense can be made out of a description string, or if an input expression (IX) has an invalid format or version byte. When this bit is set in a filter's error field, the filter will match nothing, but this is not the proper way to "turn off" a filter, use ActivateCxObj().

COERR_BADTYPE

A type specific operation, such as SetFilterIX(), was called for object 'co', but 'co' isn't of the proper type.

co

the commodity object to get the accumulated error from (may be NULL)

error

the accumulated error, or 0 if 'co' is NULL

SetFilter(), SetFilterIX(), AttachCxObj(), ActivateCxObj(), ClearCxObjError()