# \[Feature #3627\] catch$B$N%V%m%C%/$r:F\<B9T$9$k%a%=%C%I(B

**URL:** <https://www.ruby-forum.com/t/feature-3627-catch-b-n-v-m-c-r-f-b9t-9-k-a-c-i-b/192376>\
**Category:** Development\
**Created:** [July 29, 2010, 10:33am UTC](https://www.ruby-forum.com/t/feature-3627-catch-b-n-v-m-c-r-f-b9t-9-k-a-c-i-b/192376 "2010-07-29T10:33:39Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Makoto\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e8c25b/32.png) [@Makoto\_K](https://www.ruby-forum.com/u/Makoto_K)\
**Post date:** [July 29, 2010, 10:33am UTC](https://www.ruby-forum.com/t/feature-3627-catch-b-n-v-m-c-r-f-b9t-9-k-a-c-i-b/192376/1 "2010-07-29T10:33:39Z")

</div>

Feature #3627: catche$B$N%V%m%C%/$r:F\<B9T$9$k%a%=%C%Ie(B  
[http://redmine.ruby-lang.org/issues/show/3627](http://redmine.ruby-lang.org/issues/show/3627)

e$B5/I\<\<Te(B: Makoto K.  
e$B%9%F!\<%?%9e(B: Open, e$BM%@hEYe(B: Low  
e$B%+%F%4%je(B: core, Target version: 2.0

catche$B$He(Bthrowe$B$G!"%M%9%H$rHt$S1[$($?e(Bbreake$B$N$h$&$J$3$H$,$G$-$k$o$1$G$9$,!“F1MM$N%M%9%H$rHt$S1[$($?e(Bnexte$B$N$h$&$J$b$N!”$r8=:\_$Ne(Brubye$B$G$d$k$N$O\>/!9LLE]$G$9!#e(B  
retrye$B$rMxMQ$7$F!"e(B

tag = Class.new Exception  
begin  
e$B!!e(B…  
e$B!!e(Braise tag  
e$B!!e(B…  
rescue tag  
e$B!!e(Bretry  
end

e$B$H$$$&\<j$b$J$$$G$O$“$j$^$;$s$,L5M}LpM}$C$]$$$G$9!#e(B  
throwe$B$N$+$o$j$K!”$J$K$+JL$N%a%=%C%I!Je(Brewinde$B$H$$$&L\>A0$O$I$&$G$7$g$&!)!K$r\<B9T$9$k$H!“e(Bcatche$B$N%V%m%C%/$,:F\<B9T$5$l$k!”$H$$$&$N$O$I$&$G$7$g$&$+!)e(B

---

<div class="post-metadata">

**Author:** ![Makoto\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e8c25b/32.png) [@Makoto\_K](https://www.ruby-forum.com/u/Makoto_K)\
**Post date:** [July 30, 2010, 12:36am UTC](https://www.ruby-forum.com/t/feature-3627-catch-b-n-v-m-c-r-f-b9t-9-k-a-c-i-b/192376/2 "2010-07-30T00:36:07Z")

</div>

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

In message “Re: [ruby-dev:41892] [Feature #3627]  
catche$B$N%V%m%C%/$r:F\<B9T$9$k%a%=%C%Ie(B”  
on Thu, 29 Jul 2010 17:33:11 +0900, Makoto K.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|throwe$B$N$+$o$j$K!"$J$K$+JL$N%a%=%C%I!Je(Brewinde$B$H$$$&L\>A0$O$I$&$G$7$g$&!)!K$r\<B9T$9$k$H!“e(Bcatche$B$N%V%m%C%/$,:F\<B9T$5$l$k!”$H$$$&$N$O$I$&$G$7$g$&$+!)e(B

e$B4pK\E\*$J%“%$%G%#%”$rH]Dj$9$k$o$1$G$O$"$j$^$;$s$,!"e(B

- catche$B%V%m%C%/$N:F\<B9T$,I,MW$J%f!\<%9%1!\<%9$,\<($5$l$F$$$J$$e(B
- rewinde$B$H$$$&L\>A0$O$$$m$$$m$J$H$3$m$G;H$o$l$F$$$k$N$GK\>$^e(B  
e$B$7$/$J$$e(B

e$B$N$G!"8=;~E@$G$O;?@.$7$^$;$s!#e(B

---

<div class="post-metadata">

**Author:** ![Makoto\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e8c25b/32.png) [@Makoto\_K](https://www.ruby-forum.com/u/Makoto_K)\
**Post date:** [July 31, 2010, 12:17pm UTC](https://www.ruby-forum.com/t/feature-3627-catch-b-n-v-m-c-r-f-b9t-9-k-a-c-i-b/192376/3 "2010-07-31T12:17:21Z")

</div>

e$B$-$7$b$H$G$9e(B

> |throwe$B$N$+$o$j$K!"$J$K$+JL$N%a%=%C%I!Je(Brewinde$B$H$$$&L\>A0$O$I$&$G$7$g$&!)!K$r\<B9T$9$k$H!“e(Bcatche$B$N%V%m%C%/$,:F\<B9T$5$l$k!”$H$$$&$N$O$I$&$G$7$g$&$+!)e(B
> 
> e$B4pK\E\*$J%"%$%G%#%"$rH]Dj$9$k$o$1$G$O$"$j$^$;$s$,!"e(B
> 
> - catche$B%V%m%C%/$N:F\<B9T$,I,MW$J%f!\<%9%1!\<%9$,\<($5$l$F$$$J$$e(B
> - rewinde$B$H$$$&L\>A0$O$$$m$$$m$J$H$3$m$G;H$o$l$F$$$k$N$GK\>$^e(B  
> e$B$7$/$J$$e(B
> 
> e$B$N$G!"8=;~E@$G$O;?@.$7$^$;$s!#e(B

e$B%f!\<%9%1!\<%9$G$9$,!"e(BThe Art of Multiprocessor Programming  
e$B$N!"e(B  
e$B%m%C%/%U%j!\<%9%-%C%W%j%9%H$Ne(B find e$B%a%=%C%I!Je(BFig.  
14.13e$B!K$re(B Ruby e$B$G=q$$$?e(B  
e$B$b$N$r\<($7$^$9!#!Je(Bbegin e$B$He(B rescue e$B$He(B retry  
e$B$GF1Ey$N$b$N$r\<BAu$7$F$$$^$9!#e(B  
e$B85$Ne(B Java e$B%3!\<%I$G$O%i%Y%kIU$-$Ne(B continue e$B$G$7$?!Ke(B

```
def find key, before_list, after_list
    retry_tag = Class.new Exception
    begin
        pp = nil
        p = @head
        @level_max.downto(0){|level|
            pp = p.links[level].get_link
            loop {
                ppp, mark = pp.links[level].get
                while mark do
                    snip = p.links[level].compare_and_set pp, ppp, 

```

false, false  
unless snip then  
raise retry\_tag  
end  
pp = ppp  
ppp, mark = pp.links[level].get  
end  
if pp.key. **send** (@cmp\_op, key) == -1 then  
p = pp  
pp = ppp  
else  
break  
end  
}  
before\_list[level] = p  
after\_list[level] = pp  
}  
if pp.key. **send** (@cmp\_op, key) == 0 then  
pp  
else  
nil  
end  
rescue retry\_tag  
retry  
end  
end  
private :find

e$B$^$?!"$7$P$i$/9M$($F$\_$?$N$G$9$,!“e(BCe$B8@8l$Ge(B do { continue; }  
while (0); e$B$,e(B  
e$B%k!\<%W$K$J$i$J$$$3$H$r9M$($k$H!”%G%U%)%k%H$G$Oe(B1e$B2s$-$j$N\<B9T$,4|BT$5$l$F$$$ke(B  
catch e$B$H$NAH$\_9g$o$;$O$"$^$jNI$/$J$$$h$&$K;W$($F$-$^$7$?!#e(B

loop e$B$N%V%m%C%/$,0z?t$r\<h$k$h$&$K$7$F!"e(B  
loop {|tag|  
e$B!!e(B…  
e$B!!e(Bcontinue tag  
e$B!!e(B…  
}

e$B$H$$$&$+$?$A$G$O$I$&$G$7$g$&$+!)e(B

e$B$"$H!"L\>A0$G$9$,!"e(Bcontinue e$B$NB\>$Ke(B loop e$B$HBP$K$J$k$N$Ge(B  
pool …e$B$H$$$&$N$Oe(B  
e$B%@%a$G$9$MB?J,!#e(B

---

<div class="post-metadata">

**Author:** ![Makoto\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e8c25b/32.png) [@Makoto\_K](https://www.ruby-forum.com/u/Makoto_K)\
**Post date:** [August 2, 2010, 9:52am UTC](https://www.ruby-forum.com/t/feature-3627-catch-b-n-v-m-c-r-f-b9t-9-k-a-c-i-b/192376/4 "2010-08-02T09:52:28Z")

</div>

e$B$-$7$b$H$G$9e(B

> e$B$3$s$J$N$G$O$I$&$G$7$g$&$+!#e(B

e$B$"$j$,$H$&$4$6$$$^$9!#e(B  
while e$B$Ge(B catch  
e$B$r0O$s$@$i!"$H$$$&%"%$%G%#%"$Oe(B%rubye$B$G$$$?$@$$$F$$$?$N$G$9$,!"e(B  
e$B$&$^$/Cj\>]2=$G$-$k$N$G$9$M!#e(B

---

<div class="post-metadata">

**Author:** ![Makoto\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e8c25b/32.png) [@Makoto\_K](https://www.ruby-forum.com/u/Makoto_K)\
**Post date:** [August 1, 2010, 11:08am UTC](https://www.ruby-forum.com/t/feature-3627-catch-b-n-v-m-c-r-f-b9t-9-k-a-c-i-b/192376/5 "2010-08-01T11:08:05Z")

</div>

e$B$J$+$@$G$9!#e(B

At Sat, 31 Jul 2010 19:06:51 +0900,  
KISHIMOTO, Makoto wrote in [ruby-dev:41906]:

> loop e$B$N%V%m%C%/$,0z?t$r\<h$k$h$&$K$7$F!"e(B  
> loop {|tag|  
> e$B!!e(B…  
> e$B!!e(Bcontinue tag  
> e$B!!e(B…  
> }
> 
> e$B$H$$$&$+$?$A$G$O$I$&$G$7$g$&$+!)e(B

e$B$3$s$J$N$G$O$I$&$G$7$g$&$+!#e(B

class Loop  
def loop  
begin  
t, val = catch(self) {  
yield self  
false  
}  
end while t  
val  
end  
def next(\*values)  
Kernel.throw(self, [true, values])  
end  
def break(\*values)  
Kernel.throw(self, [false, values])  
end  
def self.loop(&block)  
new.loop(&block)  
end  
end

i = 0  
Loop.loop do |tag|  
p(i += 1)  
tag.next if i \< 3  
p “end”  
tag.break  
end

---

<div class="post-metadata">

**Author:** ![Makoto\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e8c25b/32.png) [@Makoto\_K](https://www.ruby-forum.com/u/Makoto_K)\
**Post date:** [August 27, 2010, 6:52am UTC](https://www.ruby-forum.com/t/feature-3627-catch-b-n-v-m-c-r-f-b9t-9-k-a-c-i-b/192376/6 "2010-08-27T06:52:34Z")

</div>

e$B%A%1%C%He(B #3627 e$B$,99?7$5$l$^$7$?!#e(B (by Shyouhei U.)

e$B%9%F!\<%?%9e(B Opene$B$+$ie(BRejectede$B$KJQ99e(B

## e$BDs0F;vBV$Oe(Brejecte$B$7$^$9$N$G$b$7?7$7$$%“%$%G%#%”$,$G$-$?$i$^$?EPO?$7$F$/$@$5$$!#e(B

[http://redmine.ruby-lang.org/issues/show/3627](http://redmine.ruby-lang.org/issues/show/3627)