# Def m(a=nil, b)

**URL:** <https://www.ruby-forum.com/t/def-m-a-nil-b/97894>\
**Category:** Development\
**Created:** [July 11, 2006, 5:54am UTC](https://www.ruby-forum.com/t/def-m-a-nil-b/97894 "2006-07-11T05:54:26Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [July 11, 2006, 5:54am UTC](https://www.ruby-forum.com/t/def-m-a-nil-b/97894/1 "2006-07-11T05:54:26Z")

</div>

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e$BBh0l0z?t$r\>Je(B  
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e$B$&$+!”$HA[A|$7!";n$7$F$\_$?$N$G$9$,!"$G$-$J$$$h$&$G$9!#e(B

% ./ruby -ve ‘def m(a=nil, b) end’  
ruby 1.9.0 (2006-07-10) [i686-linux]  
-e:1: syntax error, unexpected ‘)’, expecting ‘=’  
def m(a=nil, b) end  
^

def m(a=nil, \*x, b) end e$B$J$iDL$k$o$1$G$9$,!"$I$&$b;d$O$3$N5!e(B  
e$BG=$r!VI,?\0z?t$r:G8e$K$D$1$i$l$k!W$HM}2r$7$F$$$?$h$&$G$9!#e(B

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TCPServer#initialize e$B$N$h$&$K$=$&9M$($?$[$&$,JXMx$JNc$b$”$je(B  
e$B$^$9!#e(B

e$B$"$H!“e(B[ruby-dev:28715] e$B$N:G=i$NLdBj$O!”$3$N5!G=$N$H$i$($+$?e(B  
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e$B$J$N$G!"$G$-$?$i$$$$$s$G$O$J$+$m$&$+$H;W$C$?$N$G$9$,!"$I$&$Ge(B  
e$B$7$g$&e(B?

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [July 11, 2006, 6:24am UTC](https://www.ruby-forum.com/t/def-m-a-nil-b/97894/2 "2006-07-11T06:24:45Z")

</div>

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

In message “Re: [ruby-dev:29014] def m(a=nil, b)”  
on Tue, 11 Jul 2006 12:51:33 +0900, Tanaka A. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
writes:

|e$B$U$H!“e(B1.9 e$B$J$ie(B (TCPServer#initialize e$B$N$h$&$Ke(B) e$BBh0l0z?t$r\>Je(B  
|e$BN,2DG=$J%a%=%C%I$re(B def m(a=nil, b) e$B$HDj5A$G$-$k$N$G$O$J$+$me(B  
|e$B$&$+!”$HA[A|$7!“;n$7$F$\_$?$N$G$9$,!”$G$-$J$$$h$&$G$9!#e(B

e$B$G$-$^$;$s!#e(B

|def m(a=nil, \*x, b) end e$B$J$iDL$k$o$1$G$9$,!"$I$&$b;d$O$3$N5!e(B  
|e$BG=$r!VI,?\0z?t$r:G8e$K$D$1$i$l$k!W$HM}2r$7$F$$$?$h$&$G$9!#e(B

e$B$(!\<$H!“8=\>u!”$3$l$O!Ve(Breste$B0z?t$+$iI,?\0z?t$r0z$-Gm$,$9!W5!G=e(B  
e$B$G$9$M!#e(B

def m(a=nil, b)

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|def m(a=nil, \*x, b) end e$B$J$iDL$k$o$1$G$9$,!“$I$&$b;d$O$3$N5!e(B  
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|  
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e$B$H!#e(B

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

```

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [July 11, 2006, 6:42am UTC](https://www.ruby-forum.com/t/def-m-a-nil-b/97894/3 "2006-07-11T06:42:48Z")

</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$B$G$9$M!#e(B  
> e$B0z$-Gm$,$9!"$H$$$&I=8=$r;H$&$J$i!"0J2\<$NF0:n$r8+$k8B$j!"e(Brest  
> e$B0z?t$@$1$G$J$/e(B optionale$B0z?t$+$i$b0z$-Gm$,$7$^$9!#e(B

% ./ruby -e ’  
def m(a, b=nil, \*c, d)  
p [a,b,c,d]  
end  
m(1,2)’  
[1, nil, [], 2]

% ./ruby -e ’  
def m(a, b=nil, \*c)  
p [a,b,c]  
end  
m(1,2)’  
[1, 2, []]

lm(a, b=nil, \*c) e$B$Ge(B b e$B$KF~$C$F$$$?0z?t$,0z$-Gm$,$5$l$F!"e(B  
m(a, b=nil, \*c, d) e$B$G$Oe(B d e$B$KF~$C$F$$$^$9!#e(B

e$B=\>$C$F!"!Ve(Breste$B0z?t$+$iI,?\0z?t$r0z$-Gm$,$9!W5!G=$H$$$&@bL@$Oe(B  
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> def m(a=nil, b)
> 
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> 
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e$B$9$,e(B…

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [July 11, 2006, 8:57am UTC](https://www.ruby-forum.com/t/def-m-a-nil-b/97894/4 "2006-07-11T08:57:50Z")

</div>

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

In message “Re: [ruby-dev:29017] Re: def m(a=nil, b)”  
on Tue, 11 Jul 2006 13:40:40 +0900, Tanaka A. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
writes:

|\> e$B$(!\<$H!“8=\>u!”$3$l$O!Ve(Breste$B0z?t$+$iI,?\0z?t$r0z$-Gm$,$9!W5!G=e(B  
|\> e$B$G$9$M!#e(B  
|  
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|e$B0z?t$@$1$G$J$/e(B optionale$B0z?t$+$i$b0z$-Gm$,$7$^$9!#e(B

e$B$“$”!“$=$&$G$7$?!#e(B[ruby-dev:28715]e$B$r\<u$1$F$=$N$h$&$K=$@5$7$?e(B  
e$B$N$G$7$?!#$H$J$k$H!”$I$&$7$?$b$N$+$J!#e(B

|e$B$J$k$[$I!#$^$!!“;Y1g$7$?$/$J$$$N$G$”$l$P\<BAu$7$J$$$N$OM-$j$Ge(B  
|e$B$9$,!"@bL@$H\<BAu$,9g$C$F$$$J$$$N$O$I$&$+$H;W$$$^$9!#e(B

e$B$=$&$G$9$M!#@bL@$H\<BAu$O9g$o$;$?$[$&$,$h$$$H;W$$$^$9!#$G!"$Ie(B  
e$B$&9g$o$;$k$+$G$9$M!#e(B

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [July 12, 2006, 5:08am UTC](https://www.ruby-forum.com/t/def-m-a-nil-b/97894/5 "2006-07-12T05:08:38Z")

</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$B$&9g$o$;$k$+$G$9$M!#e(B  
> e$B0JA0e(B Matze$B$K$C$-$K5-=R$“$C$?$O$:$@!”$H;W$C$FC5$7$F8+$^$7$?!#e(B

mandatory arguments after splat  
[http://www.rubyist.net/~matz/20060601.html#p03](http://www.rubyist.net/~matz/20060601.html#p03)

RCR 315: allow required arguments after optional arguments  
[http://www.rcrchive.net/rcr/show/315](http://www.rcrchive.net/rcr/show/315)

e$B\>/$J$/$H$b!"e(BRCR 315 e$B$O!VI,?\0z?t$r8e$m$K$b$D$1$i$l$k!W5!G=$re(B  
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e$B$b$N$G$”$j!"e(B[ruby-dev:29014]  
e$B$N$h$&$J5!G=$bA[Dj$5$l$F$$$^$9!#e(B

Also consider the cases where the optional arguments (c,d)  
or the splatted arg array (e) aren’t there.  
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e$B$J$s$G!“e(BRCR 315 e$B$N$h$&$Je(B (e$B$”$k$$$O;d$,A[A|$7$?$h$&$Je(B)  
e$B$b$N$+e(B  
e$B$i!“e(Brest e$B$+$i$@$1!”$HJQ$($?$s$G$9$+e(B?

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [July 12, 2006, 4:23pm UTC](https://www.ruby-forum.com/t/def-m-a-nil-b/97894/6 "2006-07-12T16:23:57Z")

</div>

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

In message “Re: [ruby-dev:29020] Re: def m(a=nil, b)”  
on Tue, 11 Jul 2006 15:55:58 +0900, Yukihiro M.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|e$B$=$&$G$9$M!#@bL@$H\<BAu$O9g$o$;$?$[$&$,$h$$$H;W$$$^$9!#$G!"$Ie(B  
|e$B$&9g$o$;$k$+$G$9$M!#e(B

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