Re: Deparse isn't as reliable as I thought

Not exactly :)

C:\>perl -MO=Concise -e"@f = split ' ', shift"
9  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
8     <@> split[t5] vK ->9
3        </> pushre(/"\\s+"/ => @f) s*/64 ->4
6        <1> shift sK/1 ->7
5           <1> rv2av[t4] sKRM/1 ->6
4              <#> gv[*ARGV] s ->5
7        <$> const[IV 0] s ->8
-e syntax OK

C:\>perl -MO=Concise -e"@f = split /\s+/, shift"
9  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
8     <@> split[t5] vK ->9
3        </> pushre(/"\\s+"/ => @f) s/64 ->4
6        <1> shift sK/1 ->7
5           <1> rv2av[t4] sKRM/1 ->6
4              <#> gv[*ARGV] s ->5
7        <$> const[IV 0] s ->8
-e syntax OK

C:\>perl -MO=Concise -e"@f = split ?\s+?, shift"
9  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
8     <@> split[t5] vK ->9
3        </> pushre(/"\\s+"/ => @f) s/64 ->4
6        <1> shift sK/1 ->7
5           <1> rv2av[t4] sKRM/1 ->6
4              <#> gv[*ARGV] s ->5
7        <$> const[IV 0] s ->8
-e syntax OK
[download]

B::Deparse cautions you that the output might not be what you expect (or that it might be a bug, which you should report), but B::Concise seems to agree that there's no difference (but don't take my word for it, it might just be a similar bug).

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Comment on Re: Deparse isn't as reliable as I thought Download Code

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Re^2: Deparse isn't as reliable as I thought by harleypig (Monk) on Mar 04, 2006 at 00:21 UTC
Thanks. I didn't know about Concise. The only difference I can see in these two is the asterisk (): `</> pushre(/"\\s+"/ => @f) s/64 ->4 (split " ") </> pushre(/"\\s+"/ => @f) s/64 ->4 (split ?\s+?)` [download] The most I've been able to find out is that the '' means 'do something weird for this op' and a reference to op.h, which says 'On pushre, re is /\s+/ imp. by split " "'. We already know this. So this is gonna have to be one of those cases where I'm just gonna have to accept it as a peculiarity of perl. This is not a big issue as I won't be running into this any time soon again. Also, the magic only happens when assigning to an array, using in implied contexts or assigning to a scalar the " " is not* converted to ?\s+?. Harley J Pig	[reply] [d/l]
Re^2: Deparse isn't as reliable as I thought by ambrus (Abbot) on Mar 05, 2006 at 23:35 UTC
Well, Concise doesn't even distingush between `perl -MO=Concise -we 'warn "foo"=~/f./g'` [download] and `perl -MO=Concise -we 'warn "foo"=~/f./'` [download] so I wouldn't trust it so much.	[reply] [d/l] [select]
Re^3: Deparse isn't as reliable as I thought by BrowserUk (Patriarch) on Mar 05, 2006 at 23:52 UTC
See what happens when you put that into a list context: C:\>perl -MO=Concise -e"'foofoo' =~ /f../" 5 <@> leave[1 ref] vKP/REFC ->(end) 1 <0> enter ->2 2 <;> nextstate(main 1 -e:1) v ->3 4 </> match(/"f.."/) vKS/RTIME ->5 3 <$> const[PV "foofoo"] s ->4 -e syntax OK C:\>perl -MO=Concise -e"'foofoo' =~ /f../g" 5 <@> leave[1 ref] vKP/REFC ->(end) 1 <0> enter ->2 2 <;> nextstate(main 1 -e:1) v ->3 4 </> match(/"f.."/) vKS/RTIME ->5 3 <$> const[PV "foofoo"] s ->4 -e syntax OK C:\>perl -MO=Concise -e"() = 'foofoo' =~ /f../g" 8 <@> leave[1 ref] vKP/REFC ->(end) 1 <0> enter ->2 2 <;> nextstate(main 1 -e:1) v ->3 7 <2> aassign[t1] vKS/COMMON ->8 - <1> ex-list lK ->6 3 <0> pushmark s ->4 5 </> match(/"f.."/) lKS/RTIME ->6 4 <$> const[PV "foofoo"] s ->5 - <1> ex-list lK ->7 6 <0> pushmark s ->7 - <0> stub lPRM* ->- -e syntax OK [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]


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