🚀 go-pugleaf

In article <1992Sep30.205620.5130@quintus.com>
	pds@quintus.com (Peter D. Schachte) writes:

 |The advantage of a formalized distfix syntax extension is the same as
 |the advantage of formalized bracketing:  error detection.

Their merits are not limited to error detection.

 |For example,
 |if you wanted to add if-then-elseif-then-else-endif syntax to Prolog,
 |you could declare each of these words as an operator of the appropriate
 |precedence.

But no precedence selection can make nested if-then-else-endif valid,
as "then" and "else" cannot be declared "yfy".  On the other hand,
this can be made possible by making "if-endif" as a parentheses pair,
or probably by distfix.  In general, they give more freedom to syntax
design.

My point is that the principal difference between distfix and
parentheses is in error detection, not in the extent of such added
freedom.  As parse time error detection cannot be perfect anyway, I
think introducing parentheses would be enough.

Takashi Chikayama
ICOT