# \[Bug #1215\] irb doesn't finish evaluate on !false =\> false

**URL:** <https://www.ruby-forum.com/t/bug-1215-irb-doesnt-finish-evaluate-on-false-false/161382>\
**Category:** Development\
**Created:** [February 26, 2009, 2:04am UTC](https://www.ruby-forum.com/t/bug-1215-irb-doesnt-finish-evaluate-on-false-false/161382 "2009-02-26T02:04:14Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Nobuhiro\_IMAI](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/9f8e36/32.png) [@Nobuhiro\_IMAI](https://www.ruby-forum.com/u/Nobuhiro_IMAI)\
**Post date:** [February 26, 2009, 2:04am UTC](https://www.ruby-forum.com/t/bug-1215-irb-doesnt-finish-evaluate-on-false-false/161382/1 "2009-02-26T02:04:14Z")

</div>

Bug #1215: irb doesn’t finish evaluate on !false =\> false  
[http://redmine.ruby-lang.org/issues/show/1215](http://redmine.ruby-lang.org/issues/show/1215)

e$B5/I\<\<Te(B: Nobuhiro IMAI  
e$B%9%F!\<%?%9e(B: Open, e$BM%@hEYe(B: Normal  
e$B%+%F%4%je(B: lib  
ruby -v: ruby 1.9.2dev (2009-02-25 trunk 22626) [i686-linux]

$ irb1.9 -f  
irb(main):001:0\> RUBY\_DESCRIPTION  
=\> “ruby 1.9.2dev (2009-02-25 trunk 22626) [i686-linux]”  
irb(main):002:0\> false  
=\> false  
irb(main):003:0\> false.define\_singleton\_method(:!){p “!false”; false}  
=\> #\<Proc:0x8dd716c@(irb):3 (lambda)\>  
irb(main):004:0\> false  
“!false”  
“!false”  
irb(main):005:0\>  
irb(main):006:0\*  
irb(main):007:0\*  
irb(main):008:0\* irb(main):008:0\> =\> false

!false e$B$,e(B false e$B$rJV$9$h$&$J\>u67$@$H!"e(Birb  
e$B$,\<0$rI\>2A$7$?7k2L$rJV$5$J$$$h$&$G$9!#e(B  
e$B\<j85$G$O!"e(B^D  
e$B$r2?EY$+2!$9$HI\>2A$7$?7k2L$,JV$j$^$7$?!#\>e$NNc$G$O!"e(B005 e$B$+$ie(B  
007 e$B$^$G$Oe(B  
Enter e$B$r!"e(B008 e$B$N$H$3$m$G$Oe(B ^D e$B$re(B 2  
e$B2sF~NO$7$F$$$^$9!#e(B

e$B$k$j$^$K$O!"e(B

> e$B\<g$KO@M}\<0$NI\>2A$KH\<$C$FI{:nMQ$r0z$-5/$3$9$3$H$rL\E\*$Ke(B  
> e$B:FDj5A$9$k$b$N$HA[Dj$5$l$F$$$^$9!#e(B

e$B$H=q$+$l$F$$$k$N$G!"%P%0$H8@$($k$N$+$OHyL/$J5$$b$7$^$9$,!"e(B  
irb e$BB&$G2?$H$+$J$i$J$$$b$N$G$7$g$&$+!)e(B

---

<div class="post-metadata">

**Author:** ![Nobuhiro\_IMAI](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/9f8e36/32.png) [@Nobuhiro\_IMAI](https://www.ruby-forum.com/u/Nobuhiro_IMAI)\
**Post date:** [February 26, 2009, 2:39am UTC](https://www.ruby-forum.com/t/bug-1215-irb-doesnt-finish-evaluate-on-false-false/161382/2 "2009-02-26T02:39:25Z")

</div>

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

In message “Re: [ruby-dev:38087] [Bug #1215] irb doesn’t finish evaluate  
on !false =\> false”  
on Thu, 26 Feb 2009 10:02:45 +0900, Nobuhiro IMAI  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|!false e$B$,e(B false e$B$rJV$9$h$&$J\>u67$@$H!"e(Birb e$B$,\<0$rI\>2A$7$?7k2L$rJV$5$J$$$h$&$G$9!#e(B  
|e$B\<j85$G$O!"e(B^D e$B$r2?EY$+2!$9$HI\>2A$7$?7k2L$,JV$j$^$7$?!#\>e$NNc$G$O!"e(B005 e$B$+$ie(B 007 e$B$^$G$Oe(B  
|Enter e$B$r!"e(B008 e$B$N$H$3$m$G$Oe(B ^D e$B$re(B 2 e$B2sF~NO$7$F$$$^$9!#e(B  
|  
|e$B$k$j$^$K$O!“e(B  
|  
|\> e$B\<g$KO@M}\<0$NI\>2A$KH\<$C$FI{:nMQ$r0z$-5/$3$9$3$H$rL\E\*$Ke(B  
|\> e$B:FDj5A$9$k$b$N$HA[Dj$5$l$F$$$^$9!#e(B  
|  
|e$B$H=q$+$l$F$$$k$N$G!”%P%0$H8@$($k$N$+$OHyL/$J5$$b$7$^$9$,!"e(B  
|irb e$BB&$G2?$H$+$J$i$J$$$b$N$G$7$g$&$+!)e(B

e$BL5M}$G$7$g$&$M!#e(Bfalsee$B$N$h$&$J4pK\E\*$J%\*%V%8%'%/%H$Ne(B!e$B$r:FDj5Ae(B  
e$B$7$?\>l9g$G$b@5Ev$KF0:n$9$k%W%m%0%i%`$r5-=R$9$k$3$H$O:$Fq$G$9!#e(B  
e$B$=$s$JIiC4$r%i%$%V%i%j:n\<T$KIi$o$;$?$/$“$j$^$;$s!#e(B!e$B$N:FDj5Ae(B  
e$B$O$”$/$^$G$b\<+8J@UG$$G!#e(B