# Array $B$N(B product $B$NLa$jCM(B

**URL:** <https://www.ruby-forum.com/t/array-b-n-b-product-b-nla-jcm-b/128862>\
**Category:** Development\
**Created:** [February 12, 2008, 7:26am UTC](https://www.ruby-forum.com/t/array-b-n-b-product-b-nla-jcm-b/128862 "2008-02-12T07:26:39Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![Hideo\_Konami](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/919ad9/32.png) [@Hideo\_Konami](https://www.ruby-forum.com/u/Hideo_Konami)\
**Post date:** [February 12, 2008, 7:26am UTC](https://www.ruby-forum.com/t/array-b-n-b-product-b-nla-jcm-b/128862/1 "2008-02-12T07:26:39Z")

</div>

e$B\>.GH$G$9!#e(B

Ruby 1.9 e$B$Ne(B Array e$B%/%i%9$Ne(B product  
e$B%a%=%C%I$O;H$($=$&$@$H;W$C$F$$$ke(B  
e$B$N$G$9$,!$JV$5$l$k$N$,G[Ns$NG[Ns$K$J$k$o$1$G$9$M!#e(B

e$B3N$+$K!V=89g$ND\>@Q!W$H9M$($k$H!$=89g$C$]$$%_%V%8%’%/%H!$$3$3$G$Oe(B  
e$BG[Ns$,JV$5$l$k$N$,$$$$$N$+$b$H$$$&?t3XE_$J463P$,J,$+$i$J$/$b$J$$$Ne(B  
e$B$G$9$,!$e(Bpermutation e$B$de(B combination e$B$,e(B  
Enumerable:Enumerator e$B%/%i%9e(B  
e$B$N%\*%V%8%’%/%H$rJV$9$N$r$\_$k$H!$F1$8$h$&$KF0:n$7$?J}$,$`$7$m0l4S@-e(B  
e$B$,$"$k$h$&$K;W$$$^$9!#e(B

e$B$D$^$j!$7k2L$r$R$H$D$:$D\<h$j=P$9$N$K!$\<!$N$h$&$K=q$-J}$rJQ$($J$1$le(B  
e$B$P$J$i$J$$$N$OLLGr$/$J$$$H8D?ME\*$K46$8$k$o$1$9!#e(B

ar.permutation(n) {|x| p x}  
ar.combination(n) {|x| p x}

ar.product(ar2).each {|x| p x}

e$BG[Ns$NG[Ns$@$C$?$i$I$&$;e(B each  
e$B$G=hM}$9$k$@$m$&$H9M$($k$H!$$O$8$a$+e(B  
e$B$ie(B each e$B$G=hM}$5$l$?e(B Enumerator  
e$B$N7A$K$J$C$F$$$?$i!$$=$N$[$&$,;H$$e(B  
e$B$d$9$=$&$@$7!#$I$s$J$b$N$G$7$g$&$+!)e(B

---

<div class="post-metadata">

**Author:** ![Hideo\_Konami](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/919ad9/32.png) [@Hideo\_Konami](https://www.ruby-forum.com/u/Hideo_Konami)\
**Post date:** [February 13, 2008, 6:43am UTC](https://www.ruby-forum.com/t/array-b-n-b-product-b-nla-jcm-b/128862/2 "2008-02-13T06:43:08Z")

</div>

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

In message “Re: [ruby-dev:33712] Array e$B$Ne(B product  
e$B$NLa$jCMe(B”  
on Tue, 12 Feb 2008 15:25:46 +0900, “Hideo Konami”  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|Ruby 1.9 e$B$Ne(B Array e$B%/%i%9$Ne(B product e$B%a%=%C%I$O;H$($=$&$@$H;W$C$F$$$ke(B  
|e$B$N$G$9$,!$JV$5$l$k$N$,G[Ns$NG[Ns$K$J$k$o$1$G$9$M!#e(B

e$B$O$$!#e(B

|e$B3N$+$K!V=89g$ND\>@Q!W$H9M$($k$H!$=89g$C$]$$%_%V%8%'%/%H!$$3$3$G$Oe(B  
|e$BG[Ns$,JV$5$l$k$N$,$$$$$N$+$b$H$$$&?t3XE_$J463P$,J,$+$i$J$/$b$J$$$Ne(B  
|e$B$G$9$,!$e(Bpermutation e$B$de(B combination e$B$,e(B Enumerable:Enumerator e$B%/%i%9e(B  
|e$B$N%\*%V%8%'%/%H$rJV$9$N$r$\_$k$H!$F1$8$h$&$KF0:n$7$?J}$,$`$7$m0l4S@-e(B  
|e$B$,$"$k$h$&$K;W$$$^$9!#e(B

permutatione$B$de(Bcombinatione$B$N\>l9g$K$Oe(B

ar.permutation(n) {|x| p x}  
ar.combination(n) {|x| p x}

e$B$H$$$&;H$$J}$,!VI8=`!W$G!"%V%m%C%/$r;XDj$7$J$$\>l9g$K$Oe(B(e$BB\>$Ne(B  
e$B%V%m%C%/$r;XDj$9$k%a%=%C%I$K$J$i$$e(B)Enumeratore$B$rJV$7$F$$$^$9!#e(B

e$B0lJ}!“e(Bproducte$B$N\>l9g$K$O$”$/$^$G$bD\>@Q$r7W;;$9$k$H$$$&$3$H$G!"e(B  
e$B%V%m%C%/$r;XDj$9$kJ}K!$rDs6!$7$F$$$^$;$s!#;d\<+?H$O\<B@83h$GG[e(B  
e$BNs$ND\>@Q$r;H$&$3$H$,$J$$$N$G6qBNE\*$K%$%a!\<%8$G$-$J$$$N$G$9$,!"e(B  
e$BG[Ns$,JV$C$F$-$Fe(B

ar.product(ar2).each {|x| p x}

e$B$H$9$k$h$j$be(B

ar.product(ar2) {|x| p x}

e$B$H$9$kJ}$,$&$l$7$$$b$N$J$N$G$7$g$&$+!#$^$?!"e(BEnumeratore$B$rJV$9e(B  
e$B$H$$$&$3$H$O!“La$jCM$KBP$7$F$OB\>$NG[NsE\*%a%=%C%I$O;H$($J$$$oe(B  
e$B$1$G$9$,!”$=$NJU$O$I$&$J$N$G$7$g$&!)e(B

```
                            e$B$^$D$b$He(B e$B$f$-$R$me(B /:|)

```

---

<div class="post-metadata">

**Author:** ![Hideo\_Konami](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/919ad9/32.png) [@Hideo\_Konami](https://www.ruby-forum.com/u/Hideo_Konami)\
**Post date:** [February 13, 2008, 7:22am UTC](https://www.ruby-forum.com/t/array-b-n-b-product-b-nla-jcm-b/128862/3 "2008-02-13T07:22:27Z")

</div>

e$B@.@%$G$9!#e(B

e$BHFMQe(B Indexer  
e$B$rMQ0U$G$-$k$^$G@xIz$7$F$$$kM=Dj$@$C$?$N$G$9$,!"3J9%$NNc$,e(B  
e$B$G$F$-$?$N$G!#e(B

Yukihiro M. wrote:

> e$B$^$?!"e(BEnumeratore$B$rJV$9e(B  
> e$B$H$$$&$3$H$O!“La$jCM$KBP$7$F$OB\>$NG[NsE\*%a%=%C%I$O;H$($J$$$oe(B  
> e$B$1$G$9$,!”$=$NJU$O$I$&$J$N$G$7$g$&!)e(B

e$BNc$($P$3$l$,!"e(B[ruby-dev:33448] e$B$de(B [ruby-dev:33472]  
e$B$G=P$7$?!"e(BIndexable  
(e$B$H$$$&$+e(B Indexer) e$B$,M\_$7$/$J$k;vNc$G$9!#e(B

e$B$"$l$+$iB\>$NJ}$K65$($FD:$$$?$N$G$9$,!"!Ve(BEnumeratore$B!W$H!VG[NsE\*%a%=%C%I$re(B  
e$BHw$($?$b$N!W$O!Ve(BC++ e$B$K$\*$1$ke(B  
Iteratore$B!W$K0lHL2=$G$-!"$=$NJ,N`$K$h$k$H!"e(B

- Enumerator -\> Input Iterator
- e$BG[NsE\*%a%=%C%Ie(B -\> Random Access Iterator  
e$B$K$"$?$k$=$&$G$9!#e(B

e$B$=$7$F!"e(B

- e$B8=:_e(B Ruby e$B$K$O:G$b$f$k$$e(B input iterator  
e$B$OB8:_$9$k$,!"e(B  
e$B!!$=$l$h$j87$7$$$b$N$OA4$/$J$$e(B
- e$B$h$C$F!"$b$C$H87$7$$$b$N$,M\_$7$/$F$b!"G[Ns$K5M$a9~$`$+!"e(B  
e$B!!e(BEnumerator e$B$G2fK}$9$k$+!"FH\<+%/%i%9$r:n$k$3$H$K$J$k!#e(B
- e$B$@$+$i!"!VG[NsE\*%a%=%C%I!W$rHw$($?e(B Enumeratore$B!"e(B  
e$B!!$D$^$je(B Indexer e$B$,M\_$7$$!#e(B
- e$B$J$_!"!VG[NsE_%a%=%C%I!W$N%-%b$Oe(B [], []=, length e$B$G$"$j!“e(B  
e$B!!$3$l$i$,\<BAu$5$l$F$$$l$P!”$"$H$O$=$l$rMQ$$$F\<BAu$G$-$ke(B  
e$B$H$$$&$3$H$,8@$$$?$+$C$?$N$G$9!#e(B

---

<div class="post-metadata">

**Author:** ![Hideo\_Konami](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/919ad9/32.png) [@Hideo\_Konami](https://www.ruby-forum.com/u/Hideo_Konami)\
**Post date:** [February 14, 2008, 7:17am UTC](https://www.ruby-forum.com/t/array-b-n-b-product-b-nla-jcm-b/128862/4 "2008-02-14T07:17:30Z")

</div>

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

In message “Re: [ruby-dev:33752] Re: Array e$B$Ne(B product  
e$B$NLa$jCMe(B”  
on Wed, 13 Feb 2008 15:21:51 +0900, “NARUSE, Yui”  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|e$B$“$l$+$iB\>$NJ}$K65$($FD:$$$?$N$G$9$,!”!Ve(BEnumeratore$B!W$H!VG[NsE\*%a%=%C%I$re(B  
|e$BHw$($?$b$N!W$O!Ve(BC++ e$B$K$_$1$ke(B Iteratore$B!W$K0lHL2=$G$-!"$=$NJ,N`$K$h$k$H!"e(B  
|_ Enumerator → Input Iterator  
|\* e$BG[NsE\*%a%=%C%Ie(B → Random Access Iterator  
|e$B$K$"$?$k$=$&$G$9!#e(B

e$B\<+J,$GJY6/$9$k$Y$-$J$N$+$b$7$l$^$;$s$,!“:G6a$Ne(BC++e$B;v\>p$K$OABe(B  
e$B$$$N$Ge(B(e$B;d$,e(BC++e$B%W%m%0%i%^$@$C$?$N$Oe(B10e$BG/0J\>eA0e(B)e$B!”!Ve(BC++  
e$B$K$\*$1e(B  
e$B$ke(B Iteratore$B!W$H$$$&$N$Oe(BInput Iteratore$B$He(BRandom Access  
Iteratore$B$NB\>$K$b$$$m$$$m$"$k$s$G$9$+$M!#e(B

|e$B$=$7$F!"e(B  
|\* e$B8=:_e(B Ruby e$B$K$O:G$b$f$k$$e(B input iterator e$B$OB8:_$9$k$,!“e(B  
|e$B!!$=$l$h$j87$7$$$b$N$OA4$/$J$$e(B  
|\* e$B$h$C$F!”$b$C$H87$7$$$b$N$,M\_$7$/$F$b!"G[Ns$K5M$a9~$`$+!"e(B  
|e$B!!e(BEnumerator e$B$G2fK}$9$k$+!"FH\<+%/%i%9$r:n$k$3$H$K$J$k!#e(B

e$B$^$"!"8@$C$F$k$3$H$OJ,$+$j$^$9!#e(B

|\* e$B$@$+$i!“!VG[NsE\*%a%=%C%I!W$rHw$($?e(B Enumeratore$B!“e(B  
|e$B!!$D$^$je(B Indexer e$B$,M\_$7$$!#e(B  
|\* e$B$J$_!"!VG[NsE_%a%=%C%I!W$N%-%b$Oe(B [], []=, length e$B$G$”$j!“e(B  
|e$B!!$3$l$i$,\<BAu$5$l$F$$$l$P!”$”$H$O$=$l$rMQ$$$F\<BAu$G$-$ke(B  
|e$B$H$$$&$3$H$,8@$$$?$+$C$?$N$G$9!#e(B

e$B$&!\<$s!“e(Blengthe$B$,I,?$G$”$k$J$i$PG[Ns$K$7$F$7$^$C$F$$$1$J$$M}e(B  
e$BM3$,$"$^$j;W$$$D$+$J$$$N$G$9$,!#e(Blengthe$B$,$J$$$J$i$Pe(BLazye$B$Je(BList  
e$B$,:n$l$k$H$$$&M}M3$,;W$$$D$/$N$G$9$,!#%a%b%j8zN(!)e(B

e$B$b$&$A$g$C$H$$$m$$$m5DO@$7$J$$$H!"$J$\<e(BRandom Access Iterator  
e$B$,I,MW$J$N$+8+$($F$-$^$;$s!#e(B

```
                            e$B$^$D$b$He(B e$B$f$-$R$me(B /:|)

```

---

<div class="post-metadata">

**Author:** ![Hideo\_Konami](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/919ad9/32.png) [@Hideo\_Konami](https://www.ruby-forum.com/u/Hideo_Konami)\
**Post date:** [February 13, 2008, 10:21am UTC](https://www.ruby-forum.com/t/array-b-n-b-product-b-nla-jcm-b/128862/5 "2008-02-13T10:21:17Z")

</div>

On 2/13/08, Yukihiro M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> ar.product(ar2) {|x| p x}
> 
> e$B$H$9$kJ}$,$&$l$7$$$b$N$J$N$G$7$g$&$+!#$^$?!"e(BEnumeratore$B$rJV$9e(B  
> e$B$H$$$&$3$H$O!“La$jCM$KBP$7$F$OB\>$NG[NsE\*%a%=%C%I$O;H$($J$$$oe(B  
> e$B$1$G$9$,!”$=$NJU$O$I$&$J$N$G$7$g$&!)e(B

e$B$I$C$A$+$H$$$&$H!"$^$D$b$H$5$s$X$N1g73$J$N$G$9$,!“e(B  
e$B$`$+$7!”\<+J,$Ge(B \* e$B$He(B \*\*  
e$B$r\>e=q$-$7$FD\>@Q%\*%V%8%'%/%H$rJV$9$b$N$re(B  
e$BDj5A$7$?$H$-$O!"e(B

for i,j,k,l in [true,false]\*[-1,+1]\*\*3  
check(i,j,k,l)  
end

e$B$_$?$$$J;H$$J}$r0U?^$7$^$7$?!#69$$HO0O$N$7$i$_$D$V$7MQ$G$9!#e(B

e$B$$/$N\>l9g$O!“e(B\* e$B$K3d$jEv$F$?$/$i$$$J$N$G!“B?\<!85G[Ns$Ne(B  
e$B@8@.$H$7$F;H$C$?$o$1$G$9$,!”$=$&$9$k$H!”%V%m%C%/$r\<u$1$ke(B  
e$BM\>CO$O$J$/$J$j$^$7$?!#\<B:]!"e(Bproduct e$B$K$7$F$b%A%'!\<%s$7$Fe(B  
e$B;H$$$?$$$3$H$N$[$&$,C1H/$N%$%F%l!\<%?!\<$K;H$&$h$j$be(B  
e$BB?$$$s$8$c$J$$$G$7$g$&$+!#e(B

e$B$G!“$=$N$3$m=gNsAH$_9g$o$;$H$+$b:n$C$?$N$G$9$,!“e(B  
e$B$=$C$A$OG[Ns$,$G$+$9$.$FCM$rJV$9$N$K;~4V$,$+$+$j$9$.$k$N$H!“e(B  
e$BL\E\*$,%k!\<%W$N@8@.$N$?$a$G$”$k$3$H!”$=$l$+$i!"$I$N$_$A7+$jJV$7E,MQ$Oe(B  
e$B=PMh$J$$4X?t$J$N$G!”$_$H$J$7$/e(B each\_permutation  
e$B$H$$$&%$%F%l!\<%?!\<$He(B  
permutation e$B$H$$$&=gNs%_%V%8%'%/%H@8@.%a%=%C%I$KJ,$1$F$^$7$?!#e(B

e$B$H$$$&$h$&$J46$8$G!“D\>@Q$O7+$jJV$;$k1i;;$@$1$I!“e(B  
e$B=gNsAH$\_9g$o$;$ONs@8@.!”=89g@8@.$@$H46$8$^$7$?!#e(B  
e$B\<B:]$=$&$$$&0c$$$O$”$k$H$$/$O;W$&$N$G!"0lMM$K$I$C$A$+$N7?$K$7$F$be(B  
e$BI,$:$7$bBP\>]$NB\*$(J}$,C1=c$K$J$k$H$O9M$($K$/$$$G$9!#e(B

# 

e$B%a%s%F%J%s%9$7$F$J$$$N$Ge(B1.8e$B$G$9$iF0$/$+$I$&$+J,$+$j$^$;$s$,!"e(B

# e$B$$$A$_$&8+$($k$H$3$m$K$_$$$F$"$j$^$9!#e(B

# [http://www.notwork.org/~gotoken/ruby/p/product/](http://www.notwork.org/~gotoken/ruby/p/product/)

# [http://www.notwork.org/~gotoken/ruby/p/as-is/combinatoria.rb](http://www.notwork.org/~gotoken/ruby/p/as-is/combinatoria.rb)

e$B$4$H$1$se(B

---

<div class="post-metadata">

**Author:** ![Hideo\_Konami](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/919ad9/32.png) [@Hideo\_Konami](https://www.ruby-forum.com/u/Hideo_Konami)\
**Post date:** [February 17, 2008, 6:06am UTC](https://www.ruby-forum.com/t/array-b-n-b-product-b-nla-jcm-b/128862/6 "2008-02-17T06:06:45Z")

</div>

In article [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid),  
Yukihiro M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

> e$B$H$9$kJ}$,$&$l$7$$$b$N$J$N$G$7$g$&$+!#e(B

e$B;W$$=P$7$?$s$G$9$,!"$7$i$\_$D$V$7$K%F%9%H$r9T$&$H$-$KD\>@Q$r\<Be(B  
e$B:]$K;H$C$F$$$^$9!#$?$H$($Pe(B test\_m17n\_comb.rb e$B$de(B  
test\_sprintf\_comb.rb e$B$G$O$=$&$$$&%a%=%C%I$r$=$l$\>$l$KDj5A$7e(B  
e$B$F$$$^$9!#e(B

e$B$3$N\>l9g!“D\>@Q$r0l5$$K@8@.$9$k%a%b$j\>CHq$OITMW$J$N$G!”%$%F%l!\<e(B  
e$B%?$N$[$&$,5$J,$,$h$m$7$$$H$$$&$N$O$"$j$^$9$M!#e(B

e$B$?$@!"8=;~E@$GD4$Y$F$\_$?$H$3$m!“e(B41e$BMWAG$NG[Ns$re(B  
3e$B$DAH$\_9g$o$;e(B  
e$B$ke(B 68921e$B8D$N$,:GBg$G!”@8@.$7$F$b$=$s$J$K:$$k$H$$$&$o$1$G$O$Je(B  
e$B$$46$8$G$9$,!#e(B

---

<div class="post-metadata">

**Author:** ![Hideo\_Konami](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/919ad9/32.png) [@Hideo\_Konami](https://www.ruby-forum.com/u/Hideo_Konami)\
**Post date:** [February 15, 2008, 2:19am UTC](https://www.ruby-forum.com/t/array-b-n-b-product-b-nla-jcm-b/128862/7 "2008-02-15T02:19:48Z")

</div>

e$B@.@%$G$9!#e(B

Yukihiro M. wrote:

> e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B  
> e$B\<+J,$GJY6/$9$k$Y$-$J$N$+$b$7$l$^$;$s$,!“:G6a$Ne(BC++e$B;v\>p$K$OABe(B  
> e$B$$$N$Ge(B(e$B;d$,e(BC++e$B%W%m%0%i%^$@$C$?$N$Oe(B10e$BG/0J\>eA0e(B)e$B!”!Ve(BC++ e$B$K$\*$1e(B  
> e$B$ke(B Iteratore$B!W$H$$$&$N$Oe(BInput Iteratore$B$He(BRandom Access  
> Iteratore$B$NB\>$K$b$$$m$$$m$"$k$s$G$9$+$M!#e(B

e$B$“!”;2\>H$rD%$m$&$H;W$C$FK:$l$F$$$^$7$?!#e(B  
[http://www.kuzbass.ru/docs/isocpp/lib-iterators.html](http://www.kuzbass.ru/docs/isocpp/lib-iterators.html)

e$B?^$K$9$k$H0J2\<$NDL$j!"e(B

Random access → Bidirectional → Forward → Input  
 → Output  
e$B$=$l$\>$l0J2\<$N$h$&$K$J$j$^$9!#e(B  
Input: e$BF~NO$N$\_0lJ}8~%7!\<%1%s%7%c%ke(B  
Output: e$B=PNO$N$\_0lJ}8~%7!\<%1%s%7%c%ke(B  
Forward: e$BF~=PNO0lJ}8~%7!\<%1%s%7%c%ke(B  
Bidirectional: e$BF~=PNOAPJ}8~%7!\<%1%s%7%c%ke(B  
Random access: e$BF~=PNO%i%s%@%`%"%/%;%9e(B

e$B$A$J$\_$K!"e(Bboost e$B$@$H$A$g$C$HJQ$o$C$F!"e(B  
Incrementable → Single Pass → Forward Traversal  
 → Bidirectional Traversal → Random Access Traversal  
[http://www.boost.org/libs/iterator/doc/new-iter-concepts.html](http://www.boost.org/libs/iterator/doc/new-iter-concepts.html)  
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