# {|(a,a)|}

**URL:** <https://www.ruby-forum.com/t/a-a/112451>\
**Category:** Development\
**Created:** [August 19, 2007, 8:55am UTC](https://www.ruby-forum.com/t/a-a/112451 "2007-08-19T08:55:44Z")\
**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:** [August 19, 2007, 8:55am UTC](https://www.ruby-forum.com/t/a-a/112451/1 "2007-08-19T08:55:44Z")

</div>

e$B0J2\<$,%(%i!\<$K$J$j$^$;$s!#e(B

% ./ruby -vce ‘m() {|(a,a)|}’  
ruby 1.9.0 (2007-08-19 patchlevel 0) [i686-linux]  
Syntax OK

duplicated argument name e$B$G$O$J$$$G$7$g$&$+!#e(B

% ./ruby -vce ‘m() {|a,a|}’  
ruby 1.9.0 (2007-08-19 patchlevel 0) [i686-linux]  
-e:1: duplicated argument name  
m() {|a,a|}  
^

---

<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:** [August 20, 2007, 3:44pm UTC](https://www.ruby-forum.com/t/a-a/112451/2 "2007-08-20T15:44:13Z")

</div>

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

> e$B0J2\<$,%(%i!\<$K$J$j$^$;$s!#e(B
> 
> % ./ruby -vce ‘m() {|(a,a)|}’  
> ruby 1.9.0 (2007-08-19 patchlevel 0) [i686-linux]  
> Syntax OK
> 
> duplicated argument name e$B$G$O$J$$$G$7$g$&$+!#e(B

{|a,(a)|} e$B$@$H$J$i$J$/$F!"e(B{|(a),a|}  
e$B$@$H$J$k$3$H$K5$$,$D$-$^$7$?!#e(B

% ./ruby -ce ‘m {|a,(a)|}’  
Syntax OK  
% ./ruby -ce ‘m {|(a),a|}’  
-e:1: duplicated argument name  
m {|(a),a|}  
^

e$B$&$%$`!"$J$s$H$b!#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:** [August 22, 2007, 8:32am UTC](https://www.ruby-forum.com/t/a-a/112451/3 "2007-08-22T08:32:40Z")

</div>

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

At Sun, 19 Aug 2007 15:54:50 +0900,  
Tanaka A. wrote in [ruby-dev:31502]:

> e$B0J2\<$,%(%i!\<$K$J$j$^$;$s!#e(B
> 
> % ./ruby -vce ‘m() {|(a,a)|}’  
> ruby 1.9.0 (2007-08-19 patchlevel 0) [i686-linux]  
> Syntax OK
> 
> duplicated argument name e$B$G$O$J$$$G$7$g$&$+!#e(B

e$B$$$C$=e(Bduplicated argument  
namee$B$r$J$/$7$A$c$&$C$F$N$O$I$&$G$9$+!#e(B

# Index: parse.y

— parse.y (revision 13128)  
+++ parse.y (working copy)  
@@ -4155,4 +4155,5 @@ f\_norm\_arg : tCONSTANT  
| tIDENTIFIER  
{

- 

```
 shadowing_lvar($1);
 $$ = $1;
   }

```

@@ -4164,5 +4165,4 @@ f\_arg\_item : f\_norm\_arg  
if (!is\_local\_id($1))  
yyerror(“formal argument must be local variable”);

- 

```
 shadowing_lvar($1);
 arg_var($1);
 $$ = NEW_ARGS_AUX($1, 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:** [August 22, 2007, 9:35am UTC](https://www.ruby-forum.com/t/a-a/112451/4 "2007-08-22T09:35:11Z")

</div>

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

> e$B$$$C$=e(Bduplicated argument namee$B$r$J$/$7$A$c$&$C$F$N$O$I$&$G$9$+!#e(B

e$B$"$F$k$H!"0J2\<$N$h$&$K$J$j$^$9!#e(B

% ./ruby -ce ‘m() {|(a,a)|}’  
-e:1: duplicated argument name  
m() {|(a,a)|}  
^  
% ./ruby -ce ‘m() {|a,a|}’  
-e:1: duplicated argument name  
m() {|a,a|}  
^

e$B$h$m$7$$5sF0$@$H;W$$$^$9!#e(B

e$B$?$@!"$3$NJQ2=$r!V$J$/$7$A$c$&!W$HI=8=$9$k$N$O$h$/$o$+$j$^$;e(B  
e$B$s!#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:** [August 22, 2007, 9:50am UTC](https://www.ruby-forum.com/t/a-a/112451/5 "2007-08-22T09:50:15Z")

</div>

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

At Wed, 22 Aug 2007 16:33:42 +0900,  
Tanaka A. wrote in [ruby-dev:31593]:

> > e$B$$$C$=e(Bduplicated argument namee$B$r$J$/$7$A$c$&$C$F$N$O$I$&$G$9$+!#e(B
> 
> e$B$?$@!"$3$NJQ2=$r!V$J$/$7$A$c$&!W$HI=8=$9$k$N$O$h$/$o$+$j$^$;e(B  
> e$B$s!#e(B

e$B$$$d!"@h$N%Q%C%A$O%A%’%C%/$7$Fe(Bsyntax errore$B$K$9$k$b$N$G$9!#e(B

e$B0z?t$N=EJ#$b2D$K$7$A$c$&$H$$$&$N$O;W$$IU$$$?$@$1$G!":n$C$F$^$;$s!#e(B  
e$B$^$@!#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:** [August 23, 2007, 2:21am UTC](https://www.ruby-forum.com/t/a-a/112451/6 "2007-08-23T02:21:33Z")

</div>

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

In message “Re: [ruby-dev:31590] Re: {|(a,a)|}”  
on Wed, 22 Aug 2007 15:32:10 +0900, Nobuyoshi N.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|\> % ./ruby -vce ‘m() {|(a,a)|}’  
|\> ruby 1.9.0 (2007-08-19 patchlevel 0) [i686-linux]  
|\> Syntax OK  
|\>  
|\> duplicated argument name e$B$G$O$J$$$G$7$g$&$+!#e(B  
|  
|e$B$$$C$=e(Bduplicated argument namee$B$r$J$/$7$A$c$&$C$F$N$O$I$&$G$9$+!#e(B

e$BF1$8L\>A0$rJ#?t5v$7$F4r$7$$$3$H$,$“$j$^$9$+$M$(!#$?$@!“e(Bplace  
holdere$B$,M\_$7$$$3$H$O$”$k$s$G!”!Ve(B\_e$B!W$@$1$O=EJ#%A%'%C%/$+$i$O$:e(B  
e$B$9$H$+$O9M$($?$3$H$,$“$j$^$9!#e(Bplace  
holdere$B$NL\>A0$O!Ve(B\_e$B!W$K8BDje(B  
e$B$9$kI,MW$O$J$$!”=EJ#$7$?$N$O$5$;$??M$N\<+8J@UG$!"$H$$$&$N$b0le(B  
e$B$D$N9M$($G$9$,!#e(B

e$B$=$l$O$=$l$H$7$F!"%Q%C%A$O%3%\_%C%H$7$F$/$@$5$$!#e(B