I like the way FigForth handles message printout, either error messages or other messages.

Normally, error messages are stored on screens 4 & 5.

The meaning of MESSAGE according to the Fig Guide is:


I take this as it can also mean that messages can be stored on Screens 2 & 3 and displayed using a negative number. Although, according to the guide, it doesn't look like MESSAGE allows for block numbers to be subtracted from the starting point of Screen #4, to get to 2 or 3.

1) Is this even a good idea, or is there some reason one shouldn't do this?

1) Another question is, is there even a standard for error numbers stating that a certain error number should produce a certain error?

3) And one more question, in other Forths, are errors grouped together and printed using message #'s or are they printed inline with the definition where the error happens?

For fig Forth, what it is coded to do is its "standard".

In Forth94, there are standard THROW codes, from -255 to -1, and -4095 to -256 are reserved for system defined throw codes. Applications may use any throw codes outside this range.

I think if you wanted a block of application specific MESSAGES ... "MYMESSAGE"... you could set aside a variable for your "MYMESSAGE" base block, somewhere 4095 or less and define:

(edited -- I don't have a running fig-Forth so these are untested)

( THE USING APPLICATION SETS THIS IN ITS LOAD BLOCK )
( DEFAULT REUSES SYSTEM MESSAGES 0-15 )
VARIABLE MYMSGS 0 MYMSGS !

( LINE 15 SHOULD BE "MYMESSAGE out of range error" )
: MYMESSAGE ( mymsg# -- ) 15 UMIN MYMSGS @ 4 + 16 * MESSAGE ;