Ruby Forum Ruby-dev > defined? a &&= 0

$B0J2<$N$h$&$K!"(Bdefined? a &&= 0 $B$,(B nil 
$B$K$J$j$^$9$,!"$3$l$O0U(B
$B?^E*$G$7$g$&$+(B?

% ./ruby -ve 'p(defined? a &&= 0)'
ruby 1.9.0 (2008-05-02 revision 16284) [i686-linux]
nil

1.8 $B$G$O(B "expression" $B$G$7$?!#(B

% ruby-1.8 -ve 'p(defined? a &&= 0)'
ruby 1.8.7 (2008-05-02 patchlevel 5000) [i686-linux]
"expression"

$B%o%J%Y$H?=$7$^$9!#(B

2008/05/04 17:05 Tanaka Akira <akr@fsij.org>:
> $B0J2<$N$h$&$K!"(Bdefined? a &&= 0 $B$,(B nil $B$K$J$j$^$9$,!"$3$l$O0U(B
> $B?^E*$G$7$g$&$+(B?

$BNc30$,5/$-$J$$8B$j(B "expression" 
$B$rJV$9$h$&$K$9$k%Q%C%A$r=q$-$^$7$?!#(B
catch $B%F!<%V%k$N(B sp $B$N7W;;>e!"L58z$J(B branchif 
$B$r$O$5$s$G$"$j$^$9!#(B
$B@5$7$/$O$I$&=q$/$N$,$h$$$N$G$7$g$&$+!#(B

$B$H$3$m$G(B 1.8/1.9 $B6&DL$NF0:n$G!"(Ba $B$,L$Dj5A$N$H$-$K(B 
defined?(a||=0) $B$H$9$k$H(B
a == 0 $B$K$J$k$N$G$9$,!"$3$l$O@5$7$$F0:n$J$N$G$7$g$&$+!#(B

Index: compile.c
===================================================================
--- compile.c  (revision 16303)
+++ compile.c  (working copy)
@@ -2499,7 +2499,9 @@
   if (!lfinish[1]) {
       lfinish[1] = NEW_LABEL(nd_line(node));
   }
-  ADD_INSNL(ret, nd_line(node), branchunless, lfinish[1]);
+  ADD_INSN(ret, nd_line(node), pop);
+  ADD_INSN(ret, nd_line(node), putnil);
+  ADD_INSNL(ret, nd_line(node), branchif, lfinish[1]);
   if (needstr) {
       ADD_INSN1(ret, nd_line(node), putstring, 
rb_str_new2("expression"));
   }

$B!!$5$5$@$G$9!%(B

wanabe wrote:
> $BNc30$,5/$-$J$$8B$j(B "expression" $B$rJV$9$h$&$K$9$k%Q%C%A$r=q$-$^$7$?!#(B

$B!!$9$_$^$;$s!$;d$,;EMM$r4*0c$$$7$F$$$?$h$&$G$9!%$D$^$j!$<0$NCM$,56(B
$B$@$C$?>l9g!$(Bnil $B$rJV$9$s$@$H;W$C$F$$$^$7$?!%(B

> catch $B%F!<%V%k$N(B sp $B$N7W;;>e!"L58z$J(B branchif $B$r$O$5$s$G$"$j$^$9!#(B
> $B@5$7$/$O$I$&=q$/$N$,$h$$$N$G$7$g$&$+!#(B

$B!!$3$N$"$?$j!$>lEv$?$jE*$J(B sp 
$B$N7W;;J}<0$,$^$:$$$h$&$G$9!JD>$C$F$J$$(B
$B%P%0$N(B1$B$D!K!%(B

$B!!(Biseq $B:n@.;~$K$O!$(Barray $B$8$c$J$/$F(B tree 
$B$K$7$F!$(Bsp $B$r7W;;$9$k$7$+$J(B
$B$$$+$H9M$($F$$$k$H$3$m$G$9!%$b$C$H$$$$J}K!$,$"$k$+$b$7$l$J$$$s$G$9$,!%(B

$B!!$H$j$"$($:!$$$$?$@$-$^$7$?%Q%C%A$rF~$l$F$$$?$@$/$N$,$$$$$N$G$O$J$$(B
$B$+$H;W$$$^$9!%$7$+$7!$Nc30$r=P$9(B test $B$,L5$$$s$@$J!%(B

> $B$H$3$m$G(B 1.8/1.9 $B6&DL$NF0:n$G!"(Ba $B$,L$Dj5A$N$H$-$K(B defined?(a||=0) $B$H$9$k$H(B
> a == 0 $B$K$J$k$N$G$9$,!"$3$l$O@5$7$$F0:n$J$N$G$7$g$&$+!#(B

$B!!$3$3$O$I$&$J$s$G$7$g$&!%(B

$B$^$D$b$H(B $B$f$-$R$m$G$9(B

In message "Re: [ruby-dev:34645] Re: defined? a &&= 0"
    on Sun, 11 May 2008 15:06:11 +0900, wanabe <s.wanabe@gmail.com> 
writes:

|$B$H$3$m$G(B 1.8/1.9 $B6&DL$NF0:n$G!"(Ba $B$,L$Dj5A$N$H$-$K(B defined?(a||=0) $B$H$9$k$H(B
|a == 0 $B$K$J$k$N$G$9$,!"$3$l$O@5$7$$F0:n$J$N$G$7$g$&$+!#(B

defined?$B$KBeF~$,$"$k$H%m!<%+%kJQ?t$rDj5A$9$Y$-$@$H$O;W$C$F$$(B
$B$^$7$?$,!"<B:]$KBeF~$9$Y$-$H$^$G$O;W$C$F$$$^$;$s$G$7$?!#$H$$(B
$B$&$o$1$G%P%0$@$H;W$$$^$9!#(B