# Why only inject() accepts :symbols as if it's a Proc in Enumerable?

**URL:** <https://www.ruby-forum.com/t/why-only-inject-accepts-symbols-as-if-its-a-proc-in-enumerable/124026>\
**Category:** Development\
**Created:** [December 23, 2007, 6:53pm UTC](https://www.ruby-forum.com/t/why-only-inject-accepts-symbols-as-if-its-a-proc-in-enumerable/124026 "2007-12-23T18:53:41Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![sugie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/82dd89/32.png) [@sugie](https://www.ruby-forum.com/u/sugie)\
**Post date:** [December 23, 2007, 6:53pm UTC](https://www.ruby-forum.com/t/why-only-inject-accepts-symbols-as-if-its-a-proc-in-enumerable/124026/1 "2007-12-23T18:53:41Z")

</div>

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$ ruby-trunk -ve ‘p (1…10).inject(:+)’  
ruby 1.9.0 (2007-12-24 revision 0) [i686-linux]  
-e:1: warning: (…) interpreted as grouped expression  
55

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(1…10).map(:to\_s)  
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in `to_s': wrong number of arguments(1 for 0) (ArgumentError) from -e:1:in`’

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inject(reduce)e$B$N$_$,e(B

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(1…10).inject(&:+)

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# 

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# Enumeratore$B!W$r:n$l$J$$!"$H$$$&Nc30$,$G$-$k5$$,$7$^$9e(B

---

<div class="post-metadata">

**Author:** ![sugie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/82dd89/32.png) [@sugie](https://www.ruby-forum.com/u/sugie)\
**Post date:** [December 23, 2007, 8:03pm UTC](https://www.ruby-forum.com/t/why-only-inject-accepts-symbols-as-if-its-a-proc-in-enumerable/124026/2 "2007-12-23T20:03:27Z")

</div>

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

In message “Re: [ruby-dev:32691] Why only inject() accepts :symbols as  
if it’s a Proc in Enumerable?”  
on Mon, 24 Dec 2007 02:53:00 +0900, Tadashi S.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|e$B$=$N8e%=!\<%9$r\<P$aFI$_$7$?$N$G$9$,!"$I$&$be(BEnumerablee$B$NCf$G$Oe(B  
|inject(reduce)e$B$N$_$,e(B  
|  
|e$B!V%V%m%C%/$,M?$($i$l$:!“$+$D0z?t$Ke(BSymbole$B$r;XDj$7$?\>l9g!“e(B  
| Symbole$B$re(BProce$B$H$7$F8+$ke(B(e$B$H$$$&$+!”$=$N$^$^e(Bfuncall()e$B$9$ke(B)e$B!We(B  
|  
|e$B$H$$$&;EMM$G$”$k$h$&$G$9!#e(B  
|  
|1.8e$B$G$OEvA3L58z$G$“$k$N$O3NG’$7$?$N$G$9$,!”\>e5-$O0U?^E\*$J$b$N$G$7$g$&e(B  
|e$B$+!#$^$?$I$N$h$&$J@\_7W\>e$NM}M3$,$"$k$N$G$7$g$&$+!#e(B

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|e$B$9$,!“FCJL$JM}M3$,L5$$8B$j$O$H$j$”$($:B7$($F$_$$$?J}$,!"$D$^$j$Oe(B  
|  
| (1…10).inject(&:+)  
|  
|e$B$HL@\<(E_$Ke(B&e$B$Ge(BSymbol#to\_proce$B$r8F$S=P$9$h$&%f!\<%6$KMW5a$7$?J}$,NI$$$H;W$&e(B  
|e$B$N$G$9$,!”$I$&$G$7$g$&$+!#e(B

mape$B$K0z?t$H$7$F%7%s%%k$rM?$($F$b!"e(Binjecte$B$[$I!V0U?^DL$j!W$He(B  
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|# e$B$G$J$$$H!“6KC\<$JNc$G$9$,!Ve(Binitiale$B$,e(BSymbole$B$G$”$ke(Binjecte$B$Ne(B  
|# Enumeratore$B!W$r:n$l$J$$!"$H$$$&Nc30$,$G$-$k5$$,$7$^$9e(B

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

```