I pushed a refactoring patch (4a55356 - reproduced below) that
needs some review.
The idea is that the equality operators don't need to be printed
differently from the other operators. They were, in order to allow for
a function #'parenthsize-equality to ensure that expressions like
(= (= a b) c) and (= a (= b c)) are printed with parenthesized operands.
However, as I read the code, there is no possibility that the default
operator printer would ever not parenthesize those operands. In
other words, the mechanism is superfluous. A further explanation
is given in the commit message below.
All the tests pass and I observe no change in the compiled output of
our application, but this is still the kind of change that someone
should look over.
Daniel
commit 4a55356d6d09715fbd10a01c1b9019e013e42663
Author: Daniel Gackle <danielgackle(a)gmail.com>
Date: Sun Feb 24 17:09:41 2013 -0700
Refactoring: got rid of PARENTHESIZE-EQUALITY.
There is no need for PARENTHESIZE-EQUALITY as distinct from
PRINT-OP-ARGUMENT, because the latter always parenthesizes equality
expressions when they are an operand in some other equality
expression. (In such a case, OP and ARG-OP have the same precedence,
and neither is associative.)
diff --git a/src/printer.lisp b/src/printer.lisp
index 348f55a..f07a5b2 100644
--- a/src/printer.lisp
+++ b/src/printer.lisp
@@ -145,10 +145,8 @@ vice-versa.")
(defmethod ps-print ((number number))
(format *psw-stream* (if (integerp number) "~D" "~F") number))
-(defvar %equality-ops '(ps-js:== ps-js:!= ps-js:=== ps-js:!==))
-
(let ((precedence-table (make-hash-table :test 'eq)))
- (loop for level in `((ps-js:getprop ps-js:aref ps-js:funcall)
+ (loop for level in '((ps-js:getprop ps-js:aref ps-js:funcall)
(ps-js:new)
(ps-js:lambda) ;; you won't find this in JS books
(ps-js:++ ps-js:-- ps-js:post++ ps-js:post--)
@@ -157,7 +155,7 @@ vice-versa.")
(ps-js:- ps-js:+)
(ps-js:<< ps-js:>> ps-js:>>>)
(ps-js:< ps-js:> ps-js:<= ps-js:>= ps-js:instanceof
ps-js:in)
- ,%equality-ops
+ (ps-js:== ps-js:!= ps-js:=== ps-js:!==)
(ps-js:&)
(ps-js:^)
(ps-js:\|)
@@ -218,21 +216,12 @@ vice-versa.")
(defprinter ps-js:post-- (x)
(ps-print x)"--")
-(defprinter (ps-js:+ ps-js:- ps-js:* ps-js:/ ps-js:% ps-js:&& ps-js:\|\|
ps-js:& ps-js:\| ps-js:-= ps-js:+= ps-js:*= ps-js:/= ps-js:%= ps-js:^
ps-js:<< ps-js:>> ps-js:&= ps-js:^= ps-js:\|= ps-js:= ps-js:in ps-js:>
ps-js:>= ps-js:< ps-js:<=)
+(defprinter (ps-js:+ ps-js:- ps-js:* ps-js:/ ps-js:% ps-js:&& ps-js:\|\|
ps-js:& ps-js:\| ps-js:-= ps-js:+= ps-js:*= ps-js:/= ps-js:%= ps-js:^
ps-js:<< ps-js:>> ps-js:&= ps-js:^= ps-js:\|= ps-js:= ps-js:in ps-js:>
ps-js:>= ps-js:< ps-js:<= ps-js:== ps-js:!= ps-js:=== ps-js:!==)
(&rest args)
(loop for (arg . remaining) on args do
(print-op-argument op arg)
(when remaining (format *psw-stream* " ~(~A~) " op))))
-(defprinter (ps-js:== ps-js:!= ps-js:=== ps-js:!==) (x y)
- (flet ((parenthesize-equality (form)
- (if (and (consp form) (member (car form) %equality-ops))
- (parenthesize-print form)
- (print-op-argument op form))))
- (parenthesize-equality x)
- (format *psw-stream* " ~A " op)
- (parenthesize-equality y)))
-
(defprinter ps-js:aref (array &rest indices)
(print-op-argument 'ps-js:aref array)
(dolist (idx indices)
