Re: print particular lines question

[Andy Bach]

> Every time $ shows up, it is a different scalar.

Ah ... I was mistakenly thinking it was akin to $_ etc, where you could just 
use it for "free" but it persisted as any var would. So, in:
 raku -e 'for  -> $alpha {  for (1..14) { say (state $ = $alpha)++; }  }

it's the "state" that keeping it around, but only ... arrgh! I'm going to have 
to read
https://docs.raku.org/language/variables#The_state_declarator

a few more times ... $ normally doesn't need state, but if you want the 
assignment to happen just once (as above), you need to explicitly add the 
state.  Without an assignment:
 raku -e 'for  -> $alpha {  for (1..14) { say  $++; }  }'   # 0-13 0-13
 raku -e 'for  -> $alpha {  for (1..14) { say state $++; }  }'  # 0-13 
0-13

Those the same, but
 raku -e 'for  -> $alpha {  for (1..14) { say ( $ = $alpha)++; }  }
just shows AA and NN 14 times.  Because the inner for loops block is being 
"rerun", the state-liness of $ works, but when the outer loop loops (from AA to 
NN) the inner block and the inner version of $ go away.
 raku -e 'for  -> $alpha {  for (1..14) { say (state $ = $alpha)++; say 
"d2: " ~ ++$ }  }'
AA
d2: 1
AB
d2: 2
...

By Geoffrey, I think I almost have it!

Thanks!




From: yary 
Sent: Tuesday, September 1, 2020 6:16 PM
To: Andy Bach 
Cc: William Michels ; perl6-users 
Subject: Re: print particular lines question

Every time $ shows up, it is a different scalar.

$=1; say $;

is similar to

my $anonONE=1; say $anonTWO;

thus they are very limited use

-y


On Tue, Sep 1, 2020 at 3:55 PM Andy Bach 
mailto:andy_b...@wiwb.uscourts.gov>> wrote:
> My first clue that something is amiss is in your third line of code when the  
> return skips "AA" and starts "AB, AC, AD". That suggests to me that the 
> two step assign/printf call is playing havoc with the $ anonymous variable

Missed that about the missing AA - does the same thing  with a named var, 
though:
 raku -e 'for  -> $alpha {  for (1..14) { (state $sv = $alpha)++;  
printf("d: %s\n", $sv ) } }'
d: AB
d: AC

So
 raku -e 'for  -> $alpha {  for (1..14) { say (state $sv = $alpha)++;  
printf("d: %s\n", $sv ) } }'
AA
d: AB
AB
d: AC

Ah, the increment happens the initial assignment.
$sv = "AA";
$sv++;
print $sv;  # AB

but the
say (state $sv = $alpha)++

says the result of the assignment, then the increment.  My confusion was more 
about my inability to use "$" anywhere else.
 raku -e 'for  -> $alpha {  for (1..14) { say (state $ = $alpha)++;  
printf("d: %s\n", $ ) } }'
AA
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in block  at -e line 1
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in any join at gen/moar/stage2/NQPCORE.setting line 1075
d:
AB
Use of uninitialized value of type Any in string context.
...

break it out of the parens, and it loses some "stateness":
 raku -e 'for  -> $alpha {  for (1..14) { say state $ = $alpha; $++;  
printf("d: %s\n", $ ) } }'
AA
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in block  at -e line 1
...
AA

but the named doesn't
 raku -e 'for  -> $alpha {  for (1..14) { state $sv = $alpha; say $sv; 
$sv++;  printf("d: %s\n", $sv ) } }'
AA
d: AB
AB
d: AC





From: William Michels mailto:w...@caa.columbia.edu>>
Sent: Tuesday, September 1, 2020 5:30 PM
To: Andy Bach mailto:andy_b...@wiwb.uscourts.gov>>
Cc: yary mailto:not@gmail.com>>; perl6-users 
mailto:perl6-users@perl.org>>
Subject: Re: print particular lines question

My first clue that something is amiss is in your third line of code when the  
return skips "AA" and starts "AB, AC, AD". That suggests to me that the two 
step assign/printf call is playing havoc with the $ anonymous variable. Try 
this instead:

~$ raku -e 'for  -> $alpha {  for (1..14) { printf("d: %s\n", (state $ = 
$alpha)++ ) }; };'
d: AA
d: AB
d: AC
d: AD
d: AE
d: AF
d: AG
d: AH
d: AI
d: AJ
d: AK
d: AL
d: AM
d: AN
d: NN
d: NO
d: NP
d: NQ
d: NR
d: NS
d: NT
d: NU
d: NV
d: NW
d: NX
d: NY
d: NZ
d: OA

HTH, Bill.

On Tue, Sep 1, 2020 at 2:57 PM Andy Bach 
mailto:andy_b...@wiwb.uscourts.gov>> wrote:
I'm barely hanging on with the "$" so ... so from:
raku -e 'for  -> $alpha { for (1..14) {   print (state $ = $alpha)++ ~ " 
"  } }'
AA AB AC AD AE AF

I tried an actual, er, non-anon var
# raku -e 'for  -> $alpha { for (1..14) {   print (state $sv = $alpha)++ 
~ " "  } }'
AA AB AC AD AE AF ...

and then I tried
r

Re: print particular lines question

[yary]

Every time $ shows up, it is a different scalar.

$=1; say $;

is similar to

my $anonONE=1; say $anonTWO;

thus they are very limited use

-y


On Tue, Sep 1, 2020 at 3:55 PM Andy Bach 
wrote:

> > My first clue that something is amiss is in your third line of code when
> the  return skips "AA" and starts "AB, AC, AD". That suggests to me
> that the two step assign/printf call is playing havoc with the $ anonymous
> variable
>
> Missed that about the missing AA - does the same thing  with a named var,
> though:
>  raku -e 'for  -> $alpha {  for (1..14) { (state $sv = $alpha)++;
>  printf("d: %s\n", $sv ) } }'
> d: AB
> d: AC
>
> So
>  raku -e 'for  -> $alpha {  for (1..14) { say (state $sv =
> $alpha)++;  printf("d: %s\n", $sv ) } }'
> AA
> d: AB
> AB
> d: AC
>
> Ah, the increment happens the initial assignment.
> $sv = "AA";
> $sv++;
> print $sv;  # AB
>
> but the
> say (state $sv = $alpha)++
>
> says the result of the assignment, then the increment.  My confusion was
> more about my inability to use "$" anywhere else.
>  raku -e 'for  -> $alpha {  for (1..14) { say (state $ = $alpha)++;
>  printf("d: %s\n", $ ) } }'
> AA
> Use of uninitialized value of type Any in string context.
> Methods .^name, .raku, .gist, or .say can be used to stringify it to
> something meaningful.
>   in block  at -e line 1
> Use of uninitialized value of type Any in string context.
> Methods .^name, .raku, .gist, or .say can be used to stringify it to
> something meaningful.
>   in any join at gen/moar/stage2/NQPCORE.setting line 1075
> d:
> AB
> Use of uninitialized value of type Any in string context.
> ...
>
> break it out of the parens, and it loses some "stateness":
>  raku -e 'for  -> $alpha {  for (1..14) { say state $ = $alpha;
> $++;  printf("d: %s\n", $ ) } }'
> AA
> Use of uninitialized value of type Any in string context.
> Methods .^name, .raku, .gist, or .say can be used to stringify it to
> something meaningful.
>   in block  at -e line 1
> ...
> AA
>
> but the named doesn't
>  raku -e 'for  -> $alpha {  for (1..14) { state $sv = $alpha; say
> $sv; $sv++;  printf("d: %s\n", $sv ) } }'
> AA
> d: AB
> AB
> d: AC
>
>
>
>
> --
> *From:* William Michels 
> *Sent:* Tuesday, September 1, 2020 5:30 PM
> *To:* Andy Bach 
> *Cc:* yary ; perl6-users 
> *Subject:* Re: print particular lines question
>
> My first clue that something is amiss is in your third line of code when
> the  return skips "AA" and starts "AB, AC, AD". That suggests to me
> that the two step assign/printf call is playing havoc with the $ anonymous
> variable. Try this instead:
>
> ~$ raku -e 'for  -> $alpha {  for (1..14) { printf("d: %s\n",
> (state $ = $alpha)++ ) }; };'
> d: AA
> d: AB
> d: AC
> d: AD
> d: AE
> d: AF
> d: AG
> d: AH
> d: AI
> d: AJ
> d: AK
> d: AL
> d: AM
> d: AN
> d: NN
> d: NO
> d: NP
> d: NQ
> d: NR
> d: NS
> d: NT
> d: NU
> d: NV
> d: NW
> d: NX
> d: NY
> d: NZ
> d: OA
>
> HTH, Bill.
>
> On Tue, Sep 1, 2020 at 2:57 PM Andy Bach 
> wrote:
>
> I'm barely hanging on with the "$" so ... so from:
> raku -e 'for  -> $alpha { for (1..14) {   print (state $ =
> $alpha)++ ~ " "  } }'
> AA AB AC AD AE AF
>
> I tried an actual, er, non-anon var
> # raku -e 'for  -> $alpha { for (1..14) {   print (state $sv =
> $alpha)++ ~ " "  } }'
> AA AB AC AD AE AF ...
>
> and then I tried
> raku -e 'for  -> $alpha {  for (1..14) { (state $sv = $alpha)++;
>  printf("d: %s\n", $sv ) } }'
> d: AB
> d: AC
> d: AD
> d: AE
> d: AF
> ...
>
> but back to "$"
>  raku -e 'for  -> $alpha {  for (1..14) { (state $ = $alpha)++;
>  printf("d: %s\n", $ ) } }'
> Use of uninitialized value of type Any in string context.
> Methods .^name, .raku, .gist, or .say can be used to stringify it to
> something meaningful.
>   in block  at -e line 1
> Use of uninitialized value of type Any in string context.
> Methods .^name, .raku, .gist, or .say can be used to stringify it to
> something meaningful.
>   in any join at gen/moar/stage2/NQPCORE.setting line 1075
> d:
>
> [27 more times]
>
> I used printf hoping the %s context would stringify "$" as trying any of
> the suggested "methods" complain of a missing "self"
>  raku -e 'for  -> $alpha {  for (1..14) { (state $ = $alpha)++;
>  printf("d: %s\n", $.raku ) } }'
> ===

Re: print particular lines question

[Andy Bach]

> My first clue that something is amiss is in your third line of code when the  
> return skips "AA" and starts "AB, AC, AD". That suggests to me that the 
> two step assign/printf call is playing havoc with the $ anonymous variable

Missed that about the missing AA - does the same thing  with a named var, 
though:
 raku -e 'for  -> $alpha {  for (1..14) { (state $sv = $alpha)++;  
printf("d: %s\n", $sv ) } }'
d: AB
d: AC

So
 raku -e 'for  -> $alpha {  for (1..14) { say (state $sv = $alpha)++;  
printf("d: %s\n", $sv ) } }'
AA
d: AB
AB
d: AC

Ah, the increment happens the initial assignment.
$sv = "AA";
$sv++;
print $sv;  # AB

but the
say (state $sv = $alpha)++

says the result of the assignment, then the increment.  My confusion was more 
about my inability to use "$" anywhere else.
 raku -e 'for  -> $alpha {  for (1..14) { say (state $ = $alpha)++;  
printf("d: %s\n", $ ) } }'
AA
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in block  at -e line 1
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in any join at gen/moar/stage2/NQPCORE.setting line 1075
d:
AB
Use of uninitialized value of type Any in string context.
...

break it out of the parens, and it loses some "stateness":
 raku -e 'for  -> $alpha {  for (1..14) { say state $ = $alpha; $++;  
printf("d: %s\n", $ ) } }'
AA
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in block  at -e line 1
...
AA

but the named doesn't
 raku -e 'for  -> $alpha {  for (1..14) { state $sv = $alpha; say $sv; 
$sv++;  printf("d: %s\n", $sv ) } }'
AA
d: AB
AB
d: AC




____
From: William Michels 
Sent: Tuesday, September 1, 2020 5:30 PM
To: Andy Bach 
Cc: yary ; perl6-users 
Subject: Re: print particular lines question

My first clue that something is amiss is in your third line of code when the  
return skips "AA" and starts "AB, AC, AD". That suggests to me that the two 
step assign/printf call is playing havoc with the $ anonymous variable. Try 
this instead:

~$ raku -e 'for  -> $alpha {  for (1..14) { printf("d: %s\n", (state $ = 
$alpha)++ ) }; };'
d: AA
d: AB
d: AC
d: AD
d: AE
d: AF
d: AG
d: AH
d: AI
d: AJ
d: AK
d: AL
d: AM
d: AN
d: NN
d: NO
d: NP
d: NQ
d: NR
d: NS
d: NT
d: NU
d: NV
d: NW
d: NX
d: NY
d: NZ
d: OA

HTH, Bill.

On Tue, Sep 1, 2020 at 2:57 PM Andy Bach 
mailto:andy_b...@wiwb.uscourts.gov>> wrote:
I'm barely hanging on with the "$" so ... so from:
raku -e 'for  -> $alpha { for (1..14) {   print (state $ = $alpha)++ ~ " 
"  } }'
AA AB AC AD AE AF

I tried an actual, er, non-anon var
# raku -e 'for  -> $alpha { for (1..14) {   print (state $sv = $alpha)++ 
~ " "  } }'
AA AB AC AD AE AF ...

and then I tried
raku -e 'for  -> $alpha {  for (1..14) { (state $sv = $alpha)++;  
printf("d: %s\n", $sv ) } }'
d: AB
d: AC
d: AD
d: AE
d: AF
...

but back to "$"
 raku -e 'for  -> $alpha {  for (1..14) { (state $ = $alpha)++;  
printf("d: %s\n", $ ) } }'
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in block  at -e line 1
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in any join at gen/moar/stage2/NQPCORE.setting line 1075
d:

[27 more times]

I used printf hoping the %s context would stringify "$" as trying any of the 
suggested "methods" complain of a missing "self"
 raku -e 'for  -> $alpha {  for (1..14) { (state $ = $alpha)++;  
printf("d: %s\n", $.raku ) } }'
===SORRY!=== Error while compiling -e
Variable $.raku used where no 'self' is available
at -e:1
--> v = $alpha)++;  printf("d: %s\n", $.raku⏏ ) } }
expecting any of:
term

So I'm missing something about "$", I think






From: William Michels via perl6-users 
mailto:perl6-users@perl.org>>
Sent: Tuesday, September 1, 2020 3:17 PM
To: yary mailto:not@gmail.com>>
Cc: perl6-users mailto:perl6-users@perl.org>>
Subject: Re: print particular lines question

I tried combining Larry's code and Yary's code, variously using
"state" or "INIT" or "BEGIN". This is what I saw:

~$ raku -e 'for  -> $alpha { for (1..14) { print (state $ =
$alpha)++ ~ " " } }'
AA AB AC AD AE AF AG AH AI AJ AK AL AM AN NN NO NP NQ NR NS NT NU NV
NW NX NY NZ OA

~$ raku -e 'for  

Re: print particular lines question

[William Michels via perl6-users]

My first clue that something is amiss is in your third line of code when
the  return skips "AA" and starts "AB, AC, AD". That suggests to me
that the two step assign/printf call is playing havoc with the $ anonymous
variable. Try this instead:

~$ raku -e 'for  -> $alpha {  for (1..14) { printf("d: %s\n", (state
$ = $alpha)++ ) }; };'
d: AA
d: AB
d: AC
d: AD
d: AE
d: AF
d: AG
d: AH
d: AI
d: AJ
d: AK
d: AL
d: AM
d: AN
d: NN
d: NO
d: NP
d: NQ
d: NR
d: NS
d: NT
d: NU
d: NV
d: NW
d: NX
d: NY
d: NZ
d: OA

HTH, Bill.

On Tue, Sep 1, 2020 at 2:57 PM Andy Bach 
wrote:

> I'm barely hanging on with the "$" so ... so from:
> raku -e 'for  -> $alpha { for (1..14) {   print (state $ =
> $alpha)++ ~ " "  } }'
> AA AB AC AD AE AF
>
> I tried an actual, er, non-anon var
> # raku -e 'for  -> $alpha { for (1..14) {   print (state $sv =
> $alpha)++ ~ " "  } }'
> AA AB AC AD AE AF ...
>
> and then I tried
> raku -e 'for  -> $alpha {  for (1..14) { (state $sv = $alpha)++;
>  printf("d: %s\n", $sv ) } }'
> d: AB
> d: AC
> d: AD
> d: AE
> d: AF
> ...
>
> but back to "$"
>  raku -e 'for  -> $alpha {  for (1..14) { (state $ = $alpha)++;
>  printf("d: %s\n", $ ) } }'
> Use of uninitialized value of type Any in string context.
> Methods .^name, .raku, .gist, or .say can be used to stringify it to
> something meaningful.
>   in block  at -e line 1
> Use of uninitialized value of type Any in string context.
> Methods .^name, .raku, .gist, or .say can be used to stringify it to
> something meaningful.
>   in any join at gen/moar/stage2/NQPCORE.setting line 1075
> d:
>
> [27 more times]
>
> I used printf hoping the %s context would stringify "$" as trying any of
> the suggested "methods" complain of a missing "self"
>  raku -e 'for  -> $alpha {  for (1..14) { (state $ = $alpha)++;
>  printf("d: %s\n", $.raku ) } }'
> ===SORRY!=== Error while compiling -e
> Variable $.raku used where no 'self' is available
> at -e:1
> --> v = $alpha)++;  printf("d: %s\n", $.raku⏏ ) } }
> expecting any of:
> term
>
> So I'm missing something about "$", I think
>
>
>
>
>
> --
> *From:* William Michels via perl6-users 
> *Sent:* Tuesday, September 1, 2020 3:17 PM
> *To:* yary 
> *Cc:* perl6-users 
> *Subject:* Re: print particular lines question
>
> I tried combining Larry's code and Yary's code, variously using
> "state" or "INIT" or "BEGIN". This is what I saw:
>
> ~$ raku -e 'for  -> $alpha { for (1..14) { print (state $ =
> $alpha)++ ~ " " } }'
> AA AB AC AD AE AF AG AH AI AJ AK AL AM AN NN NO NP NQ NR NS NT NU NV
> NW NX NY NZ OA
>
> ~$ raku -e 'for  -> $alpha { for (1..14) { print (INIT $ =
> $alpha)++ ~ " " } }'
> 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
>
> ~$ raku -e 'for  -> $alpha { for (1..14) { print (BEGIN $ =
> $alpha)++ ~ " " } }'
> 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
>
> Expected?  --Bill.
>
> On Tue, Sep 1, 2020 at 11:44 AM yary  wrote:
> >
> >
> > Thanks, that's cool, and shows me something I was wondering about
> >
> > On Tue, Sep 1, 2020 at 11:36 AM Larry Wall  wrote:
> >>
> >> If you want to re-initialize a state variable, it's probably better to
> make
> >> it explicit with the state declarator:
> >>
> >> $ raku -e "for  { for (1..2) { say (state $ = 'AAA')++ } }"
> >> AAA
> >> AAB
> >> AAA
> >> AAB
> >
> >
> > $ raku -e 'for  -> $alpha { for (1..3) { say (state $ = $alpha)++
> } }'
> > AA
> > AB
> > AC
> > OO
> > OP
> > OQ
> >
>

Re: print particular lines question

[Andy Bach]

I'm barely hanging on with the "$" so ... so from:
raku -e 'for  -> $alpha { for (1..14) {   print (state $ = $alpha)++ ~ " 
"  } }'
AA AB AC AD AE AF

I tried an actual, er, non-anon var
# raku -e 'for  -> $alpha { for (1..14) {   print (state $sv = $alpha)++ 
~ " "  } }'
AA AB AC AD AE AF ...

and then I tried
raku -e 'for  -> $alpha {  for (1..14) { (state $sv = $alpha)++;  
printf("d: %s\n", $sv ) } }'
d: AB
d: AC
d: AD
d: AE
d: AF
...

but back to "$"
 raku -e 'for  -> $alpha {  for (1..14) { (state $ = $alpha)++;  
printf("d: %s\n", $ ) } }'
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in block  at -e line 1
Use of uninitialized value of type Any in string context.
Methods .^name, .raku, .gist, or .say can be used to stringify it to something 
meaningful.
  in any join at gen/moar/stage2/NQPCORE.setting line 1075
d:

[27 more times]

I used printf hoping the %s context would stringify "$" as trying any of the 
suggested "methods" complain of a missing "self"
 raku -e 'for  -> $alpha {  for (1..14) { (state $ = $alpha)++;  
printf("d: %s\n", $.raku ) } }'
===SORRY!=== Error while compiling -e
Variable $.raku used where no 'self' is available
at -e:1
--> v = $alpha)++;  printf("d: %s\n", $.raku⏏ ) } }
expecting any of:
term

So I'm missing something about "$", I think





________
From: William Michels via perl6-users 
Sent: Tuesday, September 1, 2020 3:17 PM
To: yary 
Cc: perl6-users 
Subject: Re: print particular lines question

I tried combining Larry's code and Yary's code, variously using
"state" or "INIT" or "BEGIN". This is what I saw:

~$ raku -e 'for  -> $alpha { for (1..14) { print (state $ =
$alpha)++ ~ " " } }'
AA AB AC AD AE AF AG AH AI AJ AK AL AM AN NN NO NP NQ NR NS NT NU NV
NW NX NY NZ OA

~$ raku -e 'for  -> $alpha { for (1..14) { print (INIT $ =
$alpha)++ ~ " " } }'
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

~$ raku -e 'for  -> $alpha { for (1..14) { print (BEGIN $ =
$alpha)++ ~ " " } }'
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Expected?  --Bill.

On Tue, Sep 1, 2020 at 11:44 AM yary  wrote:
>
>
> Thanks, that's cool, and shows me something I was wondering about
>
> On Tue, Sep 1, 2020 at 11:36 AM Larry Wall  wrote:
>>
>> If you want to re-initialize a state variable, it's probably better to make
>> it explicit with the state declarator:
>>
>> $ raku -e "for  { for (1..2) { say (state $ = 'AAA')++ } }"
>> AAA
>> AAB
>> AAA
>> AAB
>
>
> $ raku -e 'for  -> $alpha { for (1..3) { say (state $ = $alpha)++ } }'
> AA
> AB
> AC
> OO
> OP
> OQ
>

Re: print particular lines question

[yary]

Yes, because INIT and BEGIN happen before runtime, and $alpha is set at
runtime! Hence my original BEGIN example using a constant to set the first
value.

Another reason to prefer "state" over those phasers... unless you want a
counter over the lifetime of the process, which is valid.

-y


On Tue, Sep 1, 2020 at 1:17 PM William Michels 
wrote:

> I tried combining Larry's code and Yary's code, variously using
> "state" or "INIT" or "BEGIN". This is what I saw:
>
> ~$ raku -e 'for  -> $alpha { for (1..14) { print (state $ =
> $alpha)++ ~ " " } }'
> AA AB AC AD AE AF AG AH AI AJ AK AL AM AN NN NO NP NQ NR NS NT NU NV
> NW NX NY NZ OA
>
> ~$ raku -e 'for  -> $alpha { for (1..14) { print (INIT $ =
> $alpha)++ ~ " " } }'
> 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
>
> ~$ raku -e 'for  -> $alpha { for (1..14) { print (BEGIN $ =
> $alpha)++ ~ " " } }'
> 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
>
> Expected?  --Bill.
>
> On Tue, Sep 1, 2020 at 11:44 AM yary  wrote:
> >
> >
> > Thanks, that's cool, and shows me something I was wondering about
> >
> > On Tue, Sep 1, 2020 at 11:36 AM Larry Wall  wrote:
> >>
> >> If you want to re-initialize a state variable, it's probably better to
> make
> >> it explicit with the state declarator:
> >>
> >> $ raku -e "for  { for (1..2) { say (state $ = 'AAA')++ } }"
> >> AAA
> >> AAB
> >> AAA
> >> AAB
> >
> >
> > $ raku -e 'for  -> $alpha { for (1..3) { say (state $ = $alpha)++
> } }'
> > AA
> > AB
> > AC
> > OO
> > OP
> > OQ
> >
>

Re: print particular lines question

[William Michels via perl6-users]

I tried combining Larry's code and Yary's code, variously using
"state" or "INIT" or "BEGIN". This is what I saw:

~$ raku -e 'for  -> $alpha { for (1..14) { print (state $ =
$alpha)++ ~ " " } }'
AA AB AC AD AE AF AG AH AI AJ AK AL AM AN NN NO NP NQ NR NS NT NU NV
NW NX NY NZ OA

~$ raku -e 'for  -> $alpha { for (1..14) { print (INIT $ =
$alpha)++ ~ " " } }'
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

~$ raku -e 'for  -> $alpha { for (1..14) { print (BEGIN $ =
$alpha)++ ~ " " } }'
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Expected?  --Bill.

On Tue, Sep 1, 2020 at 11:44 AM yary  wrote:
>
>
> Thanks, that's cool, and shows me something I was wondering about
>
> On Tue, Sep 1, 2020 at 11:36 AM Larry Wall  wrote:
>>
>> If you want to re-initialize a state variable, it's probably better to make
>> it explicit with the state declarator:
>>
>> $ raku -e "for  { for (1..2) { say (state $ = 'AAA')++ } }"
>> AAA
>> AAB
>> AAA
>> AAB
>
>
> $ raku -e 'for  -> $alpha { for (1..3) { say (state $ = $alpha)++ } }'
> AA
> AB
> AC
> OO
> OP
> OQ
>

Re: print particular lines question

[yary]

Thanks, that's cool, and shows me something I was wondering about

On Tue, Sep 1, 2020 at 11:36 AM Larry Wall  wrote:

> If you want to re-initialize a state variable, it's probably better to make
> it explicit with the state declarator:
>
> $ raku -e "for  { for (1..2) { say (state $ = 'AAA')++ } }"
> AAA
> AAB
> AAA
> AAB
>

$ raku -e 'for  -> $alpha { for (1..3) { say (state $ = $alpha)++ }
}'
AA
AB
AC
OO
OP
OQ

Re: print particular lines question

[Larry Wall]

On Mon, Aug 31, 2020 at 05:05:53PM -0700, yary wrote:
: I like this better for alpha counter
: 
: raku -e "for (1..4) { say (BEGIN $ = 'AAA')++ }"
: 
: with BEGIN, the assignment of AAA happens once. With the earlier ||= it
: checks each time through the loop.
: -y

Careful with that, though, since BEGIN/INIT happen only once ever (and in the
context of the top-level run), so the state variable acts more like a global:

$ raku -e "for  { for (1..2) { say (BEGIN $ = 'AAA')++ } }"
AAA
AAB
AAC
AAD

$ raku -e "for  { for (1..2) { say (INIT $ = 'AAA')++ } }"
AAA
AAB
AAC
AAD

If you want to re-initialize a state variable, it's probably better to make
it explicit with the state declarator:

$ raku -e "for  { for (1..2) { say (state $ = 'AAA')++ } }"
AAA
AAB
AAA
AAB

Larry

Re: print particular lines question

[yary]

Nope $_ is the "default topic" if you want to use the jargon. It has a
name, the underscore character.

$ is a nameless variable, jargon is "anonymous scalar"

$_ is different specialness from $

-y


On Mon, Aug 31, 2020 at 5:13 PM ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:

> On 2020-08-31 17:03, yary wrote:
> > anonymous variable
>
> Would be safe thinking it had the same properties as `$_`?
>

Re: print particular lines question

[ToddAndMargo via perl6-users]

On 2020-08-31 17:03, yary wrote:

anonymous variable


Would be safe thinking it had the same properties as `$_`?

Re: print particular lines question

[yary]

I like this better for alpha counter

raku -e "for (1..4) { say (BEGIN $ = 'AAA')++ }"

with BEGIN, the assignment of AAA happens once. With the earlier ||= it
checks each time through the loop.
-y


On Mon, Aug 31, 2020 at 5:03 PM yary  wrote:

> Not even a reset- every time there's a $ by itself it is a new/different
> anonymous variable. So it is only useful where it is never referred to
> anywhere else.
>
> $ raku -e "for (1..4) { say $++, ' ,  ', ++$; say 'again- ',$;}"
>
> 0 ,  1
>
> again- (Any)
>
> 1 ,  2
>
> again- (Any)
>
> 2 ,  3
>
> again- (Any)
>
> 3 ,  4
>
> again- (Any)
>
> Hmm, how to make an alpha counter?
>
> $ raku -e "for (1..4) { say ($ ||= 'AAA')++ }"
>
> AAA
>
> AAB
>
> AAC
>
> AAD
>
> There is also anonymous @ and % but I don't have an example off the top of
> my head.
> -y
>
>
> On Mon, Aug 31, 2020 at 4:57 PM ToddAndMargo via perl6-users <
> perl6-users@perl.org> wrote:
>
>> On 2020-08-31 16:53, ToddAndMargo via perl6-users wrote:
>> >>> On Mon, Aug 31, 2020, 4:20 PM ToddAndMargo via perl6-users
>> >>> mailto:perl6-users@perl.org>> wrote:
>> >>>
>> >>> On 2020-08-31 05:53, Brian Duggan wrote:
>> >>>  > On Monday, August 24, Curt Tilmes wrote:
>> >>>  >> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'
>> >>>  >
>> >>>  > The -n flag is an option here too:
>> >>>  >
>> >>>  > raku -ne '.say if $++ == 3|2|5' Lines.txt
>> >>>  >
>> >>>  > Brian
>> >>>  >
>> >>>
>> >
>>  Hi Bill,
>> 
>>  Works beatifically! And no bash pipe!
>> 
>>  $ raku -ne '.say if $++ == 3|2|5' Lines.txt
>>  Line 2
>>  Line 3
>>  Line 5
>> 
>>  What is `$++`?
>> 
>>  -T
>> 
>> >
>> > On 2020-08-31 16:36, yary wrote:
>> >> $ by itself is an anonymous variable, putting ++ after starts it at 0
>> >> (hmm or nil?) and increments up.
>> >>
>> >> By putting the plus plus first, ++$, it will start at 1, thanks to
>> >> pre-increment versus post increment
>> >>
>> >
>> > Hi Yary,
>> >
>> > Excellent instructions!  It is a counter.   I found
>> > it over on
>> >
>> >  https://docs.raku.org/perl6.html
>> >
>> > with a search on `$++`.  But I had to pick it up
>> > from "context"
>> >
>> >
>> >
>> > $ p6 'my @x=<"a" "b" "c">; for @x -> $i { print $++," ", ++$, " ", $i,
>> > "\n";}'
>> > 0 1 "a"
>> > 1 2 "b"
>> > 2 3 "c"
>> >
>> > Question: does the counter restart after its use, or do
>> > I need to do it myself?
>> >
>> > -T
>> >
>>
>> To answer my own question.  It resets itself:
>>
>> $ p6 'my @x=<"a" "b" "c">; for @x -> $i { print $++, " ", ++$, " ", $i,
>> "\n" }; print "\n", $++, "\n";'
>> 0 1 "a"
>> 1 2 "b"
>> 2 3 "c"
>>
>> 0
>>
>>
>>
>> --
>> ~~
>> Computers are like air conditioners.
>> They malfunction when you open windows
>> ~~
>>
>

Re: print particular lines question

[Aureliano Guedes]

Depends where in your code the $++ is.
It may play as global or as local.

raku -e 'for 1..3 {say $++}; say $++'

On Mon, Aug 31, 2020 at 9:03 PM ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:

>
> >  adn
>
> fixed
>


-- 
Aureliano Guedes
skype: aureliano.guedes
contato:  (11) 94292-6110
whatsapp +5511942926110

Re: print particular lines question

[yary]

Not even a reset- every time there's a $ by itself it is a new/different
anonymous variable. So it is only useful where it is never referred to
anywhere else.

$ raku -e "for (1..4) { say $++, ' ,  ', ++$; say 'again- ',$;}"

0 ,  1

again- (Any)

1 ,  2

again- (Any)

2 ,  3

again- (Any)

3 ,  4

again- (Any)

Hmm, how to make an alpha counter?

$ raku -e "for (1..4) { say ($ ||= 'AAA')++ }"

AAA

AAB

AAC

AAD

There is also anonymous @ and % but I don't have an example off the top of
my head.
-y


On Mon, Aug 31, 2020 at 4:57 PM ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:

> On 2020-08-31 16:53, ToddAndMargo via perl6-users wrote:
> >>> On Mon, Aug 31, 2020, 4:20 PM ToddAndMargo via perl6-users
> >>> mailto:perl6-users@perl.org>> wrote:
> >>>
> >>> On 2020-08-31 05:53, Brian Duggan wrote:
> >>>  > On Monday, August 24, Curt Tilmes wrote:
> >>>  >> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'
> >>>  >
> >>>  > The -n flag is an option here too:
> >>>  >
> >>>  > raku -ne '.say if $++ == 3|2|5' Lines.txt
> >>>  >
> >>>  > Brian
> >>>  >
> >>>
> >
>  Hi Bill,
> 
>  Works beatifically! And no bash pipe!
> 
>  $ raku -ne '.say if $++ == 3|2|5' Lines.txt
>  Line 2
>  Line 3
>  Line 5
> 
>  What is `$++`?
> 
>  -T
> 
> >
> > On 2020-08-31 16:36, yary wrote:
> >> $ by itself is an anonymous variable, putting ++ after starts it at 0
> >> (hmm or nil?) and increments up.
> >>
> >> By putting the plus plus first, ++$, it will start at 1, thanks to
> >> pre-increment versus post increment
> >>
> >
> > Hi Yary,
> >
> > Excellent instructions!  It is a counter.   I found
> > it over on
> >
> >  https://docs.raku.org/perl6.html
> >
> > with a search on `$++`.  But I had to pick it up
> > from "context"
> >
> >
> >
> > $ p6 'my @x=<"a" "b" "c">; for @x -> $i { print $++," ", ++$, " ", $i,
> > "\n";}'
> > 0 1 "a"
> > 1 2 "b"
> > 2 3 "c"
> >
> > Question: does the counter restart after its use, or do
> > I need to do it myself?
> >
> > -T
> >
>
> To answer my own question.  It resets itself:
>
> $ p6 'my @x=<"a" "b" "c">; for @x -> $i { print $++, " ", ++$, " ", $i,
> "\n" }; print "\n", $++, "\n";'
> 0 1 "a"
> 1 2 "b"
> 2 3 "c"
>
> 0
>
>
>
> --
> ~~
> Computers are like air conditioners.
> They malfunction when you open windows
> ~~
>

Re: print particular lines question

[ToddAndMargo via perl6-users]

 adn


fixed

Re: print particular lines question

[ToddAndMargo via perl6-users]

On 2020-08-31 16:57, ToddAndMargo via perl6-users wrote:

On 2020-08-31 16:53, ToddAndMargo via perl6-users wrote:
On Mon, Aug 31, 2020, 4:20 PM ToddAndMargo via perl6-users 
mailto:perl6-users@perl.org>> wrote:


    On 2020-08-31 05:53, Brian Duggan wrote:
 > On Monday, August 24, Curt Tilmes wrote:
 >> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'
 >
 > The -n flag is an option here too:
 >
 > raku -ne '.say if $++ == 3|2|5' Lines.txt
 >
 > Brian
 >




    Hi Bill,

    Works beatifically! And no bash pipe!

    $ raku -ne '.say if $++ == 3|2|5' Lines.txt
    Line 2
    Line 3
    Line 5

    What is `$++`?

    -T



On 2020-08-31 16:36, yary wrote:
$ by itself is an anonymous variable, putting ++ after starts it at 0 
(hmm or nil?) and increments up.


By putting the plus plus first, ++$, it will start at 1, thanks to 
pre-increment versus post increment




Hi Yary,

Excellent instructions!  It is a counter.   I found
it over on

 https://docs.raku.org/perl6.html

with a search on `$++`.  But I had to pick it up
from "context"



$ p6 'my @x=<"a" "b" "c">; for @x -> $i { print $++," ", ++$, " ", $i, 
"\n";}'

0 1 "a"
1 2 "b"
2 3 "c"

Question: does the counter restart after its use, or do
I need to do it myself?

-T



To answer my own question.  It resets itself:

$ p6 'my @x=<"a" "b" "c">; for @x -> $i { print $++, " ", ++$, " ", $i, 
"\n" }; print "\n", $++, "\n";'

0 1 "a"
1 2 "b"
2 3 "c"

0





perl6.++.counters.txt

++ counters:

$++ adn ++$ are both anonymous variables

   `$++` is a counter that start at zero and increments by 1
   `++$` is a counter that start at one and increments by 1

and the reset themselves.

For example:

$ p6 'my @x=<"a" "b" "c">;
 for @x -> $i { print $++, " ", ++$, " ", $i, "\n" };
 print "\n", $++, "\n";'

0 1 "a"
1 2 "b"
2 3 "c"

0

Re: print particular lines question

[ToddAndMargo via perl6-users]

On 2020-08-31 16:53, ToddAndMargo via perl6-users wrote:
On Mon, Aug 31, 2020, 4:20 PM ToddAndMargo via perl6-users 
mailto:perl6-users@perl.org>> wrote:


    On 2020-08-31 05:53, Brian Duggan wrote:
 > On Monday, August 24, Curt Tilmes wrote:
 >> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'
 >
 > The -n flag is an option here too:
 >
 > raku -ne '.say if $++ == 3|2|5' Lines.txt
 >
 > Brian
 >




    Hi Bill,

    Works beatifically! And no bash pipe!

    $ raku -ne '.say if $++ == 3|2|5' Lines.txt
    Line 2
    Line 3
    Line 5

    What is `$++`?

    -T



On 2020-08-31 16:36, yary wrote:
$ by itself is an anonymous variable, putting ++ after starts it at 0 
(hmm or nil?) and increments up.


By putting the plus plus first, ++$, it will start at 1, thanks to 
pre-increment versus post increment




Hi Yary,

Excellent instructions!  It is a counter.   I found
it over on

     https://docs.raku.org/perl6.html

with a search on `$++`.  But I had to pick it up
from "context"



$ p6 'my @x=<"a" "b" "c">; for @x -> $i { print $++," ", ++$, " ", $i, 
"\n";}'

0 1 "a"
1 2 "b"
2 3 "c"

Question: does the counter restart after its use, or do
I need to do it myself?

-T



To answer my own question.  It resets itself:

$ p6 'my @x=<"a" "b" "c">; for @x -> $i { print $++, " ", ++$, " ", $i, 
"\n" }; print "\n", $++, "\n";'

0 1 "a"
1 2 "b"
2 3 "c"

0



--
~~
Computers are like air conditioners.
They malfunction when you open windows
~~

Re: print particular lines question

[ToddAndMargo via perl6-users]

On Mon, Aug 31, 2020, 4:20 PM ToddAndMargo via perl6-users 
mailto:perl6-users@perl.org>> wrote:


On 2020-08-31 05:53, Brian Duggan wrote:
 > On Monday, August 24, Curt Tilmes wrote:
 >> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'
 >
 > The -n flag is an option here too:
 >
 > raku -ne '.say if $++ == 3|2|5' Lines.txt
 >
 > Brian
 >




Hi Bill,

Works beatifically! And no bash pipe!

$ raku -ne '.say if $++ == 3|2|5' Lines.txt
Line 2
Line 3
Line 5

What is `$++`?

-T



On 2020-08-31 16:36, yary wrote:
$ by itself is an anonymous variable, putting ++ after starts it at 0 
(hmm or nil?) and increments up.


By putting the plus plus first, ++$, it will start at 1, thanks to 
pre-increment versus post increment




Hi Yary,

Excellent instructions!  It is a counter.   I found
it over on

https://docs.raku.org/perl6.html

with a search on `$++`.  But I had to pick it up
from "context"



$ p6 'my @x=<"a" "b" "c">; for @x -> $i { print $++," ", ++$, " ", $i, 
"\n";}'

0 1 "a"
1 2 "b"
2 3 "c"

Question: does the counter restart after its use, or do
I need to do it myself?

-T

--
~~
Computers are like air conditioners.
They malfunction when you open windows
~~

Re: print particular lines question

[yary]

Answering my own question, the operator sets the type of $. That's what
gradual typing is all about!

$ seq 5 | raku -ne "say $++"

0

1

2

3

4

$ seq 5 | raku -ne "say $ ~= 'Hi' "

Hi

HiHi

HiHiHi

HiHiHiHi

HiHiHiHiHi

$ seq 5 | raku -ne "say $++, $ ~= ' Hi' "

0 Hi

1 Hi Hi

2 Hi Hi Hi

3 Hi Hi Hi Hi

4 Hi Hi Hi Hi Hi

-y


On Mon, Aug 31, 2020 at 4:39 PM Aureliano Guedes 
wrote:

> Basically :
>
> $ raku -e 'my $a = 1; say ++$a; say $a'
> 2
> 2
> $ raku -e 'my $a = 1; say $a++; say $a'
> 1
> 2
>
> On Mon, Aug 31, 2020 at 8:36 PM yary  wrote:
>
>> $ by itself is an anonymous variable, putting ++ after starts it at 0
>> (hmm or nil?) and increments up.
>>
>> By putting the plus plus first, ++$, it will start at 1, thanks to
>> pre-increment versus post increment
>>
>> On Mon, Aug 31, 2020, 4:20 PM ToddAndMargo via perl6-users <
>> perl6-users@perl.org> wrote:
>>
>>> On 2020-08-31 05:53, Brian Duggan wrote:
>>> > On Monday, August 24, Curt Tilmes wrote:
>>> >> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'
>>> >
>>> > The -n flag is an option here too:
>>> >
>>> > raku -ne '.say if $++ == 3|2|5' Lines.txt
>>> >
>>> > Brian
>>> >
>>>
>>> Hi Bill,
>>>
>>> Works beatifically! And no bash pipe!
>>>
>>> $ raku -ne '.say if $++ == 3|2|5' Lines.txt
>>> Line 2
>>> Line 3
>>> Line 5
>>>
>>> What is `$++`?
>>>
>>> -T
>>>
>>
>
> --
> Aureliano Guedes
> skype: aureliano.guedes
> contato:  (11) 94292-6110
> whatsapp +5511942926110
>

Re: print particular lines question

[Aureliano Guedes]

Basically :

$ raku -e 'my $a = 1; say ++$a; say $a'
2
2
$ raku -e 'my $a = 1; say $a++; say $a'
1
2

On Mon, Aug 31, 2020 at 8:36 PM yary  wrote:

> $ by itself is an anonymous variable, putting ++ after starts it at 0 (hmm
> or nil?) and increments up.
>
> By putting the plus plus first, ++$, it will start at 1, thanks to
> pre-increment versus post increment
>
> On Mon, Aug 31, 2020, 4:20 PM ToddAndMargo via perl6-users <
> perl6-users@perl.org> wrote:
>
>> On 2020-08-31 05:53, Brian Duggan wrote:
>> > On Monday, August 24, Curt Tilmes wrote:
>> >> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'
>> >
>> > The -n flag is an option here too:
>> >
>> > raku -ne '.say if $++ == 3|2|5' Lines.txt
>> >
>> > Brian
>> >
>>
>> Hi Bill,
>>
>> Works beatifically! And no bash pipe!
>>
>> $ raku -ne '.say if $++ == 3|2|5' Lines.txt
>> Line 2
>> Line 3
>> Line 5
>>
>> What is `$++`?
>>
>> -T
>>
>

-- 
Aureliano Guedes
skype: aureliano.guedes
contato:  (11) 94292-6110
whatsapp +5511942926110

Re: print particular lines question

[yary]

$ by itself is an anonymous variable, putting ++ after starts it at 0 (hmm
or nil?) and increments up.

By putting the plus plus first, ++$, it will start at 1, thanks to
pre-increment versus post increment

On Mon, Aug 31, 2020, 4:20 PM ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:

> On 2020-08-31 05:53, Brian Duggan wrote:
> > On Monday, August 24, Curt Tilmes wrote:
> >> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'
> >
> > The -n flag is an option here too:
> >
> > raku -ne '.say if $++ == 3|2|5' Lines.txt
> >
> > Brian
> >
>
> Hi Bill,
>
> Works beatifically! And no bash pipe!
>
> $ raku -ne '.say if $++ == 3|2|5' Lines.txt
> Line 2
> Line 3
> Line 5
>
> What is `$++`?
>
> -T
>

Re: print particular lines question

[ToddAndMargo via perl6-users]

On 2020-08-31 05:53, Brian Duggan wrote:

On Monday, August 24, Curt Tilmes wrote:

$ cat Lines.txt | raku -e '.say for lines()[3,2,5]'


The -n flag is an option here too:

raku -ne '.say if $++ == 3|2|5' Lines.txt

Brian



Hi Bill,

Works beatifically! And no bash pipe!

$ raku -ne '.say if $++ == 3|2|5' Lines.txt
Line 2
Line 3
Line 5

What is `$++`?

-T

Re: print particular lines question

[Andy Bach]

> Not getting back line #11 with
 perl -ne 'print if $. =~ /\b[3 2 5 11]\b/' test_lines.txt

Right, as the char class contains , 1, 2, 3 and 5. I guess alternatives
 perl -ne 'print if $. =~ /\b(1|5|3|11)\b/' /tmp/lines.txt
line: 1
line: 3
line: 5
line: 11




From: William Michels 
Sent: Monday, August 31, 2020 10:28 AM
To: Brian Duggan 
Cc: Andy Bach ; perl6-users 
Subject: Re: print particular lines question

How would P5 handle line numbers > 10 ? Not getting back line #11 with
the P5 examples below:

$ raku -ne '.say if ++$ == 3|2|5|11' test_lines.txt
Line 2
Line 3
Line 5
Line 11

~$ perl -ne 'print if $. =~ /\b[3 2 5 11]\b/' test_lines.txt
Line 1
Line 2
Line 3
Line 5

~$ perl -ne 'print if $. =~ /\b[3,2, 5, 11]\b/' test_lines.txt
Line 1
Line 2
Line 3
Line 5

On Mon, Aug 31, 2020 at 8:17 AM Brian Duggan  wrote:
>
> On Monday, August 31, Andy Bach wrote:
> > >  raku -ne '.say if $++ == 3|2|5' Lines.txt
> >
> > OT, maybe, but is
> > perl -ne 'print if $. =~ /\b[325]\b/' Lines.txt
> >
> > or
> > perl -ne 'print if $c++ =~ /\b[436]\b/' Lines.txt
> >
> > the best you can do in P5?
>
> I can't think of anything better :-)
>
> Brian

Re: print particular lines question

[William Michels via perl6-users]

Thanks Yary! So that means Brian's answer in Raku can use the
smartmatch operator instead of the "==". Good to know!

~$ raku -ne '.say  if ++$ ~~ 3|5|11' test_lines.txt
Line 3
Line 5
Line 11
On Mon, Aug 31, 2020 at 8:47 AM yary  wrote:
>
> Aww don't you remember Raku's earliest(?) contribution to Perl? I was so 
> happy when this arrived, and sad over its subsequent neglect
>
> perl -ne 'no warnings "experimental"; print if $. ~~ [3,5,11]' line0-10.txt
>
>
> -y
>
>
> On Mon, Aug 31, 2020 at 8:28 AM William Michels via perl6-users 
>  wrote:
>>
>> How would P5 handle line numbers > 10 ? Not getting back line #11 with
>> the P5 examples below:
>>
>> $ raku -ne '.say if ++$ == 3|2|5|11' test_lines.txt
>> Line 2
>> Line 3
>> Line 5
>> Line 11
>>
>> ~$ perl -ne 'print if $. =~ /\b[3 2 5 11]\b/' test_lines.txt
>> Line 1
>> Line 2
>> Line 3
>> Line 5
>>
>> ~$ perl -ne 'print if $. =~ /\b[3,2, 5, 11]\b/' test_lines.txt
>> Line 1
>> Line 2
>> Line 3
>> Line 5
>>
>> On Mon, Aug 31, 2020 at 8:17 AM Brian Duggan  wrote:
>> >
>> > On Monday, August 31, Andy Bach wrote:
>> > > >  raku -ne '.say if $++ == 3|2|5' Lines.txt
>> > >
>> > > OT, maybe, but is
>> > > perl -ne 'print if $. =~ /\b[325]\b/' Lines.txt
>> > >
>> > > or
>> > > perl -ne 'print if $c++ =~ /\b[436]\b/' Lines.txt
>> > >
>> > > the best you can do in P5?
>> >
>> > I can't think of anything better :-)
>> >
>> > Brian

Re: print particular lines question

[yary]

Aww don't you remember Raku's earliest(?) contribution to Perl? I was so
happy when this arrived, and sad over its subsequent neglect

perl -ne 'no warnings "experimental"; print if $. ~~ [3,5,11]' line0-10.txt


-y


On Mon, Aug 31, 2020 at 8:28 AM William Michels via perl6-users <
perl6-users@perl.org> wrote:

> How would P5 handle line numbers > 10 ? Not getting back line #11 with
> the P5 examples below:
>
> $ raku -ne '.say if ++$ == 3|2|5|11' test_lines.txt
> Line 2
> Line 3
> Line 5
> Line 11
>
> ~$ perl -ne 'print if $. =~ /\b[3 2 5 11]\b/' test_lines.txt
> Line 1
> Line 2
> Line 3
> Line 5
>
> ~$ perl -ne 'print if $. =~ /\b[3,2, 5, 11]\b/' test_lines.txt
> Line 1
> Line 2
> Line 3
> Line 5
>
> On Mon, Aug 31, 2020 at 8:17 AM Brian Duggan  wrote:
> >
> > On Monday, August 31, Andy Bach wrote:
> > > >  raku -ne '.say if $++ == 3|2|5' Lines.txt
> > >
> > > OT, maybe, but is
> > > perl -ne 'print if $. =~ /\b[325]\b/' Lines.txt
> > >
> > > or
> > > perl -ne 'print if $c++ =~ /\b[436]\b/' Lines.txt
> > >
> > > the best you can do in P5?
> >
> > I can't think of anything better :-)
> >
> > Brian
>

Re: print particular lines question

[William Michels via perl6-users]

How would P5 handle line numbers > 10 ? Not getting back line #11 with
the P5 examples below:

$ raku -ne '.say if ++$ == 3|2|5|11' test_lines.txt
Line 2
Line 3
Line 5
Line 11

~$ perl -ne 'print if $. =~ /\b[3 2 5 11]\b/' test_lines.txt
Line 1
Line 2
Line 3
Line 5

~$ perl -ne 'print if $. =~ /\b[3,2, 5, 11]\b/' test_lines.txt
Line 1
Line 2
Line 3
Line 5

On Mon, Aug 31, 2020 at 8:17 AM Brian Duggan  wrote:
>
> On Monday, August 31, Andy Bach wrote:
> > >  raku -ne '.say if $++ == 3|2|5' Lines.txt
> >
> > OT, maybe, but is
> > perl -ne 'print if $. =~ /\b[325]\b/' Lines.txt
> >
> > or
> > perl -ne 'print if $c++ =~ /\b[436]\b/' Lines.txt
> >
> > the best you can do in P5?
>
> I can't think of anything better :-)
>
> Brian

Re: print particular lines question

[Brian Duggan]

On Monday, August 31, Andy Bach wrote: 
> >  raku -ne '.say if $++ == 3|2|5' Lines.txt
> 
> OT, maybe, but is
> perl -ne 'print if $. =~ /\b[325]\b/' Lines.txt
> 
> or
> perl -ne 'print if $c++ =~ /\b[436]\b/' Lines.txt
> 
> the best you can do in P5?

I can't think of anything better :-)

Brian

Re: print particular lines question

[Andy Bach]

>  raku -ne '.say if $++ == 3|2|5' Lines.txt

OT, maybe, but is
perl -ne 'print if $. =~ /\b[325]\b/' Lines.txt

or
perl -ne 'print if $c++ =~ /\b[436]\b/' Lines.txt

the best you can do in P5?

a

Andy Bach, BS, MSCMECFA
Systems Mangler
Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
Voice: (608) 261-5738, Cell: (608) 658-1890

"The three great problems of computer science:
compiler complexity and 'off-by-one' errors".
https://martinfowler.com/bliki/TwoHardThings.html


From: Brian Duggan 
Sent: Monday, August 31, 2020 7:53 AM
To: Curt Tilmes 
Cc: perl6-users 
Subject: Re: print particular lines question

On Monday, August 24, Curt Tilmes wrote:
> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'

The -n flag is an option here too:

   raku -ne '.say if $++ == 3|2|5' Lines.txt

Brian

Re: print particular lines question

[Brian Duggan]

On Monday, August 24, Curt Tilmes wrote: 
> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'

The -n flag is an option here too:

   raku -ne '.say if $++ == 3|2|5' Lines.txt

Brian

Re: Seq whitespace sensitivity? (was Re: print particular lines question)

[William Michels via perl6-users]

Dear Tobias (and Sean), I opened a Github issue:

https://github.com/rakudo/rakudo/issues/3881

On Wed, Aug 26, 2020 at 12:12 PM Tobias Boege  wrote:

> On Wed, 26 Aug 2020, Tobias Boege wrote:
> > Observe:
> >
> >   > 1 ...^ 20
> >   (1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)
> >
> >   > 1 ... ^20  # actually C«1 ... (0..19)»
> >   (1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)
> >
> > The documentation [1] states that the C«...» infix is list-associative
> > and while I have never seen an example of that (including in that docs
> > page), it would explain why it happily takes in your list (1) and then
> > your list (0 .. 19) and concatenates them into a sequence, without
> > applying any of the usual sequence operator magic.
>
> And I must correct myself. The associativity has nothing to do with this.
> I don't know where my mind was when I wrote that. From the documtation,
> I would blame the slurpy argument **@ for that behavior of just taking in
> lists and effectively iterating them into a new Seq, and in Rakudo it is
> apparently this special candidate:
>
>   #
> https://github.com/rakudo/rakudo/blob/e2855aa/src/core.c/operators.pm6#L129
>   multi sub infix:<...>(\a, Mu \b) {
>   Seq.new(SEQUENCE(a, b))
>   }
>
> Best,
> Tobias
>

Re: Seq whitespace sensitivity? (was Re: print particular lines question)

[Tobias Boege]

On Wed, 26 Aug 2020, Tobias Boege wrote:
> Observe:
> 
>   > 1 ...^ 20
>   (1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)
> 
>   > 1 ... ^20  # actually C«1 ... (0..19)»
>   (1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)
> 
> The documentation [1] states that the C«...» infix is list-associative
> and while I have never seen an example of that (including in that docs
> page), it would explain why it happily takes in your list (1) and then
> your list (0 .. 19) and concatenates them into a sequence, without
> applying any of the usual sequence operator magic.

And I must correct myself. The associativity has nothing to do with this.
I don't know where my mind was when I wrote that. From the documtation,
I would blame the slurpy argument **@ for that behavior of just taking in
lists and effectively iterating them into a new Seq, and in Rakudo it is
apparently this special candidate:

  # https://github.com/rakudo/rakudo/blob/e2855aa/src/core.c/operators.pm6#L129
  multi sub infix:<...>(\a, Mu \b) {
  Seq.new(SEQUENCE(a, b))
  }

Best,
Tobias

Re: Seq whitespace sensitivity? (was Re: print particular lines question)

[William Michels via perl6-users]

On Wed, Aug 26, 2020 at 10:33 AM Tobias Boege  wrote:
>
> On Wed, 26 Aug 2020, William Michels via perl6-users wrote:
> > > They can be pretty great, especially when combined with the magic op= 
> > > operators that (in essence) know about identity elements.  I've done a 
> > > few challenges on the Code Golf Stackexchange site where I wanted an 
> > > infinite sequence like this:
> > >
> > > 0, 1, -2, 3, -4, 5, -6, ...
> > >
> > > It took me a while to realize this can be expressed in Raku simply as:
> > >
> > > { $++ * ($ *= -1) } ... *
> > >
> >
> > Hi Sean, that's a neat solution! I seem to have found an oddity though
> > (whitespace sensitivity). In the REPL:
> >
> > > say { $++ * ($ *= -1) } ...21
> > (0 1 -2 3 -4 5 -6 7 -8 9 -10 11 -12 13 -14 15 -16 17 -18 19 -20 21)
> > > say { $++ * ($ *= -1) } ...^21
> > (0 1 -2 3 -4 5 -6 7 -8 9 -10 11 -12 13 -14 15 -16 17 -18 19 -20)
> > > say { $++ * ($ *= -1) } ... 21
> > (0 1 -2 3 -4 5 -6 7 -8 9 -10 11 -12 13 -14 15 -16 17 -18 19 -20 21)
> > > say { $++ * ($ *= -1) } ... ^21
> > (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20)
> >
> > I would have expected the last line of code (whitespace between "..."
> > and "^21") to give the same answer as the first three. Any ideas?
> >
>
> The difference is likely to come from the fact that "^20" as a term is
> a shorthand for the range "0..^20", while "...^" is the sequence operator
> with exclusive endpoint. Placement of whitespace will dictate where the
> little hat attaches to and thus change the meaning of the statement.
>
> Observe:
>
>   > 1 ...^ 20
>   (1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)
>
>   > 1 ... ^20  # actually C«1 ... (0..19)»
>   (1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)
>
> The documentation [1] states that the C«...» infix is list-associative
> and while I have never seen an example of that (including in that docs
> page), it would explain why it happily takes in your list (1) and then
> your list (0 .. 19) and concatenates them into a sequence, without
> applying any of the usual sequence operator magic.
>
> When you write "1 ...^20" I suppose that longest-token matching prefers
> the former interpretation as it makes the infix token longer.
>
> Best,
> Tobias
>
> [1] https://docs.raku.org/language/operators#index-entry-..._operators
>
> --
> "There's an old saying: Don't change anything... ever!" -- Mr. Monk


Thank you, Tobias! Here's my take (REPL, below):

> 1...20
(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20)

> 1... 20
(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20)

> 1...^20
(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)

> 1... ^20
(1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)

WOW. I never would have expected the last line of code above to return
a sequence starting "1, 0, 1 ..." up to 19.

Would I ever want that sequence? Couldn't I get that sequence just as
easily by asking for a sequence of (-1 ... ^20), and then calling
abs() on each element (using hyper)? See below:

> (-1... ^20)>>.abs
(1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)
>

Anyway, I opened a Github issue, and (like yourself here), Jonathan
has graciously replied. Feel free to chime in at:

https://github.com/rakudo/rakudo/issues/3881

Thanks again, Bill.

Re: Seq whitespace sensitivity? (was Re: print particular lines question)

[Tobias Boege]

On Wed, 26 Aug 2020, William Michels via perl6-users wrote:
> > They can be pretty great, especially when combined with the magic op= 
> > operators that (in essence) know about identity elements.  I've done a few 
> > challenges on the Code Golf Stackexchange site where I wanted an infinite 
> > sequence like this:
> >
> > 0, 1, -2, 3, -4, 5, -6, ...
> >
> > It took me a while to realize this can be expressed in Raku simply as:
> >
> > { $++ * ($ *= -1) } ... *
> >
> 
> Hi Sean, that's a neat solution! I seem to have found an oddity though
> (whitespace sensitivity). In the REPL:
> 
> > say { $++ * ($ *= -1) } ...21
> (0 1 -2 3 -4 5 -6 7 -8 9 -10 11 -12 13 -14 15 -16 17 -18 19 -20 21)
> > say { $++ * ($ *= -1) } ...^21
> (0 1 -2 3 -4 5 -6 7 -8 9 -10 11 -12 13 -14 15 -16 17 -18 19 -20)
> > say { $++ * ($ *= -1) } ... 21
> (0 1 -2 3 -4 5 -6 7 -8 9 -10 11 -12 13 -14 15 -16 17 -18 19 -20 21)
> > say { $++ * ($ *= -1) } ... ^21
> (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20)
> 
> I would have expected the last line of code (whitespace between "..."
> and "^21") to give the same answer as the first three. Any ideas?
> 

The difference is likely to come from the fact that "^20" as a term is
a shorthand for the range "0..^20", while "...^" is the sequence operator
with exclusive endpoint. Placement of whitespace will dictate where the
little hat attaches to and thus change the meaning of the statement.

Observe:

  > 1 ...^ 20
  (1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)

  > 1 ... ^20  # actually C«1 ... (0..19)»
  (1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)

The documentation [1] states that the C«...» infix is list-associative
and while I have never seen an example of that (including in that docs
page), it would explain why it happily takes in your list (1) and then
your list (0 .. 19) and concatenates them into a sequence, without
applying any of the usual sequence operator magic.

When you write "1 ...^20" I suppose that longest-token matching prefers
the former interpretation as it makes the infix token longer.

Best,
Tobias

[1] https://docs.raku.org/language/operators#index-entry-..._operators

-- 
"There's an old saying: Don't change anything... ever!" -- Mr. Monk

Seq whitespace sensitivity? (was Re: print particular lines question)

[William Michels via perl6-users]

> They can be pretty great, especially when combined with the magic op= 
> operators that (in essence) know about identity elements.  I've done a few 
> challenges on the Code Golf Stackexchange site where I wanted an infinite 
> sequence like this:
>
> 0, 1, -2, 3, -4, 5, -6, ...
>
> It took me a while to realize this can be expressed in Raku simply as:
>
> { $++ * ($ *= -1) } ... *
>

Hi Sean, that's a neat solution! I seem to have found an oddity though
(whitespace sensitivity). In the REPL:

> say { $++ * ($ *= -1) } ...21
(0 1 -2 3 -4 5 -6 7 -8 9 -10 11 -12 13 -14 15 -16 17 -18 19 -20 21)
> say { $++ * ($ *= -1) } ...^21
(0 1 -2 3 -4 5 -6 7 -8 9 -10 11 -12 13 -14 15 -16 17 -18 19 -20)
> say { $++ * ($ *= -1) } ... 21
(0 1 -2 3 -4 5 -6 7 -8 9 -10 11 -12 13 -14 15 -16 17 -18 19 -20 21)
> say { $++ * ($ *= -1) } ... ^21
(0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20)

I would have expected the last line of code (whitespace between "..."
and "^21") to give the same answer as the first three. Any ideas?

Best, Bill.

Re: print particular lines question

[ToddAndMargo via perl6-users]

On 2020-08-24 20:30, ToddAndMargo via perl6-users wrote:


On Mon, Aug 24, 2020 at 11:08 PM ToddAndMargo via perl6-users
 wrote:


On 2020-08-24 19:35, ToddAndMargo via perl6-users wrote:

Hi All,

I seems I should know how to do this, but
I am drawing a blank.

$ cat Lines.txt | raku -ne 'say $_;'
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11


I want to print liens 1, 3, and 7.

Assigning  `my @x=$_.lines` puts everything into $x[0]


Many thanks,
-T


This is what I have so far:

$ cat Lines.txt
Line 0
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11

$ cat Lines.txt | raku -e ' my @x=$*IN.lines; for @x[3,2,5] {say $_};'
Line 3
Line 2
Line 5


is there a quicker way to get to the point?

Many thanks,
-T


On 2020-08-24 20:24, Curt Tilmes wrote:

$ cat Lines.txt | raku -e '.say for lines()[3,2,5]'


Love it!  Thank you!


I suppose I'd better add I was looking
for a improvement

   ... | sed -n 'x,yp'

For my remaining bash programs

Re: print particular lines question

[Bruce Gray]

> On Aug 25, 2020, at 4:13 PM, yary  wrote:
> 
> > Now, does anyone have a simpler way than using the ".map" above?
> 
> There were a few in the thread!
> 
> Here's my golfing, unlike the others, this preserves the order of the lines 
> (which may or may not be desired)
> 
> raku -ne '.say if $++ == any 6,3,1' line0-10.txt

—snip—

That technique is called the "anonymous state variable", and is documented here:
https://docs.raku.org/language/variables#The_$_variable

I especially favor the `-n` flag for this problem, because we con’t have to 
“slurp” a possibly-large file into memory, and because it enables the `UNIX 
filter` behavior that allows us to specify the filename as a command-line 
argument, instead of having to pipe it in with `cat` (or `type` on Win32).

My version is almost identical, but changing to pre-increment allows you to 
specify the line numbers with the more natural numbering:
raku -ne '.say if ++$ == any(1,3,7);' Lines.txt
Line 1
Line 3
Line 7

-- 
Bruce Gray (Util of PerlMonks)

Re: print particular lines question

[William Michels via perl6-users]

Funny, I didn't see anyone compute an offset. Could you point it out?
I'm interested.

Anyway, I golfed it a little bit with a whatever-star. Below you can
preserve or rearrange the order of returned lines (#1, and #2). And
you offset using whatever value you'd like (#3):

#1
~$ raku -e '$*IN.lines[ (1,3,7).map(*-1) ].join("\n").put;' < Lines.txt
Line 1
Line 3
Line 7

#2
~$ raku -e '$*IN.lines[ (1,7,3).map(*-1) ].join("\n").put;' < Lines.txt
Line 1
Line 7
Line 3

#3
~$ raku -e '$*IN.lines[ (1,3,7).map(*+3) ].join("\n").put;' < Lines.txt
Line 5
Line 7
Line 11

HTH, Bill.


On Tue, Aug 25, 2020 at 2:13 PM yary  wrote:

> > Now, does anyone have a simpler way than using the ".map" above?
>
> There were a few in the thread!
>
> Here's my golfing, unlike the others, this preserves the order of the
> lines (which may or may not be desired)
>
> raku -ne '.say if $++ == any 6,3,1' line0-10.txt
>
> -y
>
>
> On Tue, Aug 25, 2020 at 12:03 PM William Michels via perl6-users <
> perl6-users@perl.org> wrote:
>
>> If Todd wants to print lines containing "Line 1", "Line 3", and "Line 7",
>> he's going to have to correct for zero-indexing:
>>
>> user@book:~$ raku -e '$*IN.lines[ 1,3,7 ].join("\n").put;' < Lines.txt
>> Line 2
>> Line 4
>> Line 8
>>
>> #Below: subtracting one from (1,3,7) gives the return he wants:
>>
>> user@book:~$ raku -e '$*IN.lines[ (1,3,7).map: { $_ - 1 }
>> ].join("\n").put;' < Lines.txt
>> Line 1
>> Line 3
>> Line 7
>>
>> Now, does anyone have a simpler way than using the ".map" above?
>>
>> HTH, Bill.
>>
>>
>>
>> On Tue, Aug 25, 2020 at 10:46 AM Andy Bach 
>> wrote:
>>
>>> Ah, I see, the -n reads a line and then my lines on $*IN starts with the
>>> next one
>>> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e
>>> "my @x = $*IN.lines(); say @x[0,1,7,3]; "
>>> (Line 0 Line 1 Line 7 Line 3)
>>>
>>> and so $*IN is the default for lines()
>>> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e
>>> "my @x = lines(); say @x[0,1,7,3]; "
>>> (Line 0 Line 1 Line 7 Line 3)
>>>
>>> This hangs, with and without the -n
>>> C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x =
>>> $*IN.lines(); say @x[0,1,7,3]; " lines.txt
>>>
>>> Though:
>>> C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = lines();
>>> say @x[0,1,7,3]; " lines.txt
>>> (Line 1 Line 2 Line 8 Line 4)
>>> Cannot do 'get' on a handle in binary mode
>>>   in block  at -e line 1
>>>
>>> a
>>>
>>> Andy Bach, BS, MSCMECFA
>>> Systems Mangler
>>> Internet: andy_b...@wiwb.uscourts.gov
>>> Voice: (608) 261-5738, Cell: (608) 658-1890
>>>
>>> "The three great problems of computer science:
>>> compiler complexity and 'off-by-one' errors".
>>> https://martinfowler.com/bliki/TwoHardThings.html
>>>
>>> --
>>> *From:* Andy Bach 
>>> *Sent:* Tuesday, August 25, 2020 12:18 PM
>>> *To:* Parrot Raiser <1parr...@gmail.com>
>>> *Cc:* perl6-users ; ToddAndMargo <
>>> toddandma...@zoho.com>
>>> *Subject:* Re: print particular lines question
>>>
>>> On Win10
>>> C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne
>>> "say lines()[1,7,3]; "
>>> (Line 2 Line 8 Line 4)
>>> (Line 11 Nil Nil)
>>>
>>> C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne
>>> "say lines()[1,7,3].join(qq~\n~); "
>>> Line 2
>>> Line 8
>>> Line 4
>>> Use of Nil in string context
>>>   in block  at -e line 1
>>> Use of Nil in string context
>>>   in block  at -e line 1
>>> Line 11
>>>
>>> and, speaking of that off by one problem ... lines.txt does start with
>>> "line 0"
>>> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne
>>> "my @x = $*IN.lines(); say @x[0,1,7,3]; "
>>> (Line 1 Line 2 Line 8 Line 4)
>>>
>>> a
>>>
>>> Andy Bach, BS, MSCMECFA
>>> Systems Mangler
>>> Internet: andy_b...@wiwb.uscourts.gov
>>> Voice: (608) 261-5738, Cell: (

Re: print particular lines question

[Sean McAfee]

On Tue, Aug 25, 2020 at 2:31 PM Andy Bach 
wrote:

> Pretty cool - I didn't know about the bare "$" as a magic state var.
>

They can be pretty great, especially when combined with the magic op=
operators that (in essence) know about identity elements.  I've done a few
challenges on the Code Golf Stackexchange site where I wanted an infinite
sequence like this:

0, 1, -2, 3, -4, 5, -6, ...

It took me a while to realize this can be expressed in Raku simply as:

{ $++ * ($ *= -1) } ... *

Re: print particular lines question

[Andy Bach]

> this preserves the order of the lines (which may or may not be desired)


raku -ne '.say if $++ == any 6,3,1' line0-10.txt

So there is no "$."/current input line # built-in?  I started with
# cat /tmp/lines.txt | perl -ne  'print if $. == 1 or $. == 3 or $. == 7'

but couldn't find a $. raku-ism.
https://docs.raku.org/language/variables#Special_variables

Pretty cool - I didn't know about the bare "$" as a magic state var.

a

Andy Bach, BS, MSCMECFA
Systems Mangler
Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
Voice: (608) 261-5738, Cell: (608) 658-1890

"The three great problems of computer science:
compiler complexity and 'off-by-one' errors".
https://martinfowler.com/bliki/TwoHardThings.html


From: yary 
Sent: Tuesday, August 25, 2020 4:13 PM
To: William Michels 
Cc: perl6-users ; Parrot Raiser <1parr...@gmail.com>; 
ToddAndMargo ; Andy Bach ; 
Curt Tilmes 
Subject: Re: print particular lines question

> Now, does anyone have a simpler way than using the ".map" above?

There were a few in the thread!

Here's my golfing, unlike the others, this preserves the order of the lines 
(which may or may not be desired)


raku -ne '.say if $++ == any 6,3,1' line0-10.txt

-y


On Tue, Aug 25, 2020 at 12:03 PM William Michels via perl6-users 
mailto:perl6-users@perl.org>> wrote:
If Todd wants to print lines containing "Line 1", "Line 3", and "Line 7", he's 
going to have to correct for zero-indexing:

user@book:~$ raku -e '$*IN.lines[ 1,3,7 ].join("\n").put;' < Lines.txt
Line 2
Line 4
Line 8

#Below: subtracting one from (1,3,7) gives the return he wants:

user@book:~$ raku -e '$*IN.lines[ (1,3,7).map: { $_ - 1 } ].join("\n").put;' < 
Lines.txt
Line 1
Line 3
Line 7

Now, does anyone have a simpler way than using the ".map" above?

HTH, Bill.



On Tue, Aug 25, 2020 at 10:46 AM Andy Bach 
mailto:andy_b...@wiwb.uscourts.gov>> wrote:
Ah, I see, the -n reads a line and then my lines on $*IN starts with the next 
one
C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e "my @x = 
$*IN.lines(); say @x[0,1,7,3]; "
(Line 0 Line 1 Line 7 Line 3)

and so $*IN is the default for lines()
C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e "my @x = 
lines(); say @x[0,1,7,3]; "
(Line 0 Line 1 Line 7 Line 3)

This hangs, with and without the -n
C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = $*IN.lines(); 
say @x[0,1,7,3]; " lines.txt

Though:
C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = lines(); say 
@x[0,1,7,3]; " lines.txt
(Line 1 Line 2 Line 8 Line 4)
Cannot do 'get' on a handle in binary mode
  in block  at -e line 1

a

Andy Bach, BS, MSCMECFA
Systems Mangler
Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
Voice: (608) 261-5738, Cell: (608) 658-1890

"The three great problems of computer science:
compiler complexity and 'off-by-one' errors".
https://martinfowler.com/bliki/TwoHardThings.html


From: Andy Bach 
mailto:andy_b...@wiwb.uscourts.gov>>
Sent: Tuesday, August 25, 2020 12:18 PM
To: Parrot Raiser <1parr...@gmail.com<mailto:1parr...@gmail.com>>
Cc: perl6-users mailto:perl6-users@perl.org>>; 
ToddAndMargo mailto:toddandma...@zoho.com>>
Subject: Re: print particular lines question

On Win10
C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "say 
lines()[1,7,3]; "
(Line 2 Line 8 Line 4)
(Line 11 Nil Nil)

C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "say 
lines()[1,7,3].join(qq~\n~); "
Line 2
Line 8
Line 4
Use of Nil in string context
  in block  at -e line 1
Use of Nil in string context
  in block  at -e line 1
Line 11

and, speaking of that off by one problem ... lines.txt does start with "line 0"
C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = 
$*IN.lines(); say @x[0,1,7,3]; "
(Line 1 Line 2 Line 8 Line 4)

a

Andy Bach, BS, MSCMECFA
Systems Mangler
Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
Voice: (608) 261-5738, Cell: (608) 658-1890

"The three great problems of computer science:
compiler complexity and 'off-by-one' errors".
https://martinfowler.com/bliki/TwoHardThings.html


From: Parrot Raiser <1parr...@gmail.com<mailto:1parr...@gmail.com>>
Sent: Tuesday, August 25, 2020 11:22 AM
To: Andy Bach mailto:andy_b...@wiwb.uscourts.gov>>
Cc: perl6-users mailto:perl6-users@perl.org>>; 
ToddAndMargo mailto:toddandma...@zoho.com>>
Subject: Re: print particular lines question

That will golf a little (and i

Re: print particular lines question

[yary]

> Now, does anyone have a simpler way than using the ".map" above?

There were a few in the thread!

Here's my golfing, unlike the others, this preserves the order of the lines
(which may or may not be desired)

raku -ne '.say if $++ == any 6,3,1' line0-10.txt

-y


On Tue, Aug 25, 2020 at 12:03 PM William Michels via perl6-users <
perl6-users@perl.org> wrote:

> If Todd wants to print lines containing "Line 1", "Line 3", and "Line 7",
> he's going to have to correct for zero-indexing:
>
> user@book:~$ raku -e '$*IN.lines[ 1,3,7 ].join("\n").put;' < Lines.txt
> Line 2
> Line 4
> Line 8
>
> #Below: subtracting one from (1,3,7) gives the return he wants:
>
> user@book:~$ raku -e '$*IN.lines[ (1,3,7).map: { $_ - 1 }
> ].join("\n").put;' < Lines.txt
> Line 1
> Line 3
> Line 7
>
> Now, does anyone have a simpler way than using the ".map" above?
>
> HTH, Bill.
>
>
>
> On Tue, Aug 25, 2020 at 10:46 AM Andy Bach 
> wrote:
>
>> Ah, I see, the -n reads a line and then my lines on $*IN starts with the
>> next one
>> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e "my
>> @x = $*IN.lines(); say @x[0,1,7,3]; "
>> (Line 0 Line 1 Line 7 Line 3)
>>
>> and so $*IN is the default for lines()
>> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e "my
>> @x = lines(); say @x[0,1,7,3]; "
>> (Line 0 Line 1 Line 7 Line 3)
>>
>> This hangs, with and without the -n
>> C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x =
>> $*IN.lines(); say @x[0,1,7,3]; " lines.txt
>>
>> Though:
>> C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = lines();
>> say @x[0,1,7,3]; " lines.txt
>> (Line 1 Line 2 Line 8 Line 4)
>> Cannot do 'get' on a handle in binary mode
>>   in block  at -e line 1
>>
>> a
>>
>> Andy Bach, BS, MSCMECFA
>> Systems Mangler
>> Internet: andy_b...@wiwb.uscourts.gov
>> Voice: (608) 261-5738, Cell: (608) 658-1890
>>
>> "The three great problems of computer science:
>> compiler complexity and 'off-by-one' errors".
>> https://martinfowler.com/bliki/TwoHardThings.html
>>
>> --
>> *From:* Andy Bach 
>> *Sent:* Tuesday, August 25, 2020 12:18 PM
>> *To:* Parrot Raiser <1parr...@gmail.com>
>> *Cc:* perl6-users ; ToddAndMargo <
>> toddandma...@zoho.com>
>> *Subject:* Re: print particular lines question
>>
>> On Win10
>> C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne
>> "say lines()[1,7,3]; "
>> (Line 2 Line 8 Line 4)
>> (Line 11 Nil Nil)
>>
>> C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne
>> "say lines()[1,7,3].join(qq~\n~); "
>> Line 2
>> Line 8
>> Line 4
>> Use of Nil in string context
>>   in block  at -e line 1
>> Use of Nil in string context
>>   in block  at -e line 1
>> Line 11
>>
>> and, speaking of that off by one problem ... lines.txt does start with
>> "line 0"
>> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne
>> "my @x = $*IN.lines(); say @x[0,1,7,3]; "
>> (Line 1 Line 2 Line 8 Line 4)
>>
>> a
>>
>> Andy Bach, BS, MSCMECFA
>> Systems Mangler
>> Internet: andy_b...@wiwb.uscourts.gov
>> Voice: (608) 261-5738, Cell: (608) 658-1890
>>
>> "The three great problems of computer science:
>> compiler complexity and 'off-by-one' errors".
>> https://martinfowler.com/bliki/TwoHardThings.html
>>
>> --
>> *From:* Parrot Raiser <1parr...@gmail.com>
>> *Sent:* Tuesday, August 25, 2020 11:22 AM
>> *To:* Andy Bach 
>> *Cc:* perl6-users ; ToddAndMargo <
>> toddandma...@zoho.com>
>> *Subject:* Re: print particular lines question
>>
>> That will golf a little (and improve it) to:
>>
>> $ raku -e '.say for lines()[3,2,5]' lines.txt
>>
>> but you have to remember that it's zero-based. I used the first sample
>> file and got
>> Line 4
>> Line 3
>> Line 6
>>
>> "The three great problems of computer science: compiler complexity and
>> 'off-by-one' errors".
>>
>>
>> On 8/25/20, Andy Bach  wrote:
>> >> Assigning  `my @x=$_.lines` puts everything into $x[0]
>> >
>> > Trying 

Re: print particular lines question

[William Michels via perl6-users]

If Todd wants to print lines containing "Line 1", "Line 3", and "Line 7",
he's going to have to correct for zero-indexing:

user@book:~$ raku -e '$*IN.lines[ 1,3,7 ].join("\n").put;' < Lines.txt
Line 2
Line 4
Line 8

#Below: subtracting one from (1,3,7) gives the return he wants:

user@book:~$ raku -e '$*IN.lines[ (1,3,7).map: { $_ - 1 }
].join("\n").put;' < Lines.txt
Line 1
Line 3
Line 7

Now, does anyone have a simpler way than using the ".map" above?

HTH, Bill.



On Tue, Aug 25, 2020 at 10:46 AM Andy Bach 
wrote:

> Ah, I see, the -n reads a line and then my lines on $*IN starts with the
> next one
> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e "my
> @x = $*IN.lines(); say @x[0,1,7,3]; "
> (Line 0 Line 1 Line 7 Line 3)
>
> and so $*IN is the default for lines()
> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e "my
> @x = lines(); say @x[0,1,7,3]; "
> (Line 0 Line 1 Line 7 Line 3)
>
> This hangs, with and without the -n
> C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x =
> $*IN.lines(); say @x[0,1,7,3]; " lines.txt
>
> Though:
> C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = lines();
> say @x[0,1,7,3]; " lines.txt
> (Line 1 Line 2 Line 8 Line 4)
> Cannot do 'get' on a handle in binary mode
>   in block  at -e line 1
>
> a
>
> Andy Bach, BS, MSCMECFA
> Systems Mangler
> Internet: andy_b...@wiwb.uscourts.gov
> Voice: (608) 261-5738, Cell: (608) 658-1890
>
> "The three great problems of computer science:
> compiler complexity and 'off-by-one' errors".
> https://martinfowler.com/bliki/TwoHardThings.html
>
> --
> *From:* Andy Bach 
> *Sent:* Tuesday, August 25, 2020 12:18 PM
> *To:* Parrot Raiser <1parr...@gmail.com>
> *Cc:* perl6-users ; ToddAndMargo <
> toddandma...@zoho.com>
> *Subject:* Re: print particular lines question
>
> On Win10
> C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "say
> lines()[1,7,3]; "
> (Line 2 Line 8 Line 4)
> (Line 11 Nil Nil)
>
> C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "say
> lines()[1,7,3].join(qq~\n~); "
> Line 2
> Line 8
> Line 4
> Use of Nil in string context
>   in block  at -e line 1
> Use of Nil in string context
>   in block  at -e line 1
> Line 11
>
> and, speaking of that off by one problem ... lines.txt does start with
> "line 0"
> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my
> @x = $*IN.lines(); say @x[0,1,7,3]; "
> (Line 1 Line 2 Line 8 Line 4)
>
> a
>
> Andy Bach, BS, MSCMECFA
> Systems Mangler
> Internet: andy_b...@wiwb.uscourts.gov
> Voice: (608) 261-5738, Cell: (608) 658-1890
>
> "The three great problems of computer science:
> compiler complexity and 'off-by-one' errors".
> https://martinfowler.com/bliki/TwoHardThings.html
>
> --
> *From:* Parrot Raiser <1parr...@gmail.com>
> *Sent:* Tuesday, August 25, 2020 11:22 AM
> *To:* Andy Bach 
> *Cc:* perl6-users ; ToddAndMargo <
> toddandma...@zoho.com>
> *Subject:* Re: print particular lines question
>
> That will golf a little (and improve it) to:
>
> $ raku -e '.say for lines()[3,2,5]' lines.txt
>
> but you have to remember that it's zero-based. I used the first sample
> file and got
> Line 4
> Line 3
> Line 6
>
> "The three great problems of computer science: compiler complexity and
> 'off-by-one' errors".
>
>
> On 8/25/20, Andy Bach  wrote:
> >> Assigning  `my @x=$_.lines` puts everything into $x[0]
> >
> > Trying this on windows
> >
> > C:\> raku.exe   -e "my @x = 'lines.txt'.IO.lines; say
> > @x[1,7,3].join(qq~\n~); "
> > Line 1
> > Line 7
> > Line 3
> >
> > or
> > C:\> raku.exe -e " say 'lines.txt'.IO.lines[1,7,3].join(qq~\n~); "
> > Line 1
> > Line 7
> > Line 3
> >
> > a
> >
> > Andy Bach, BS, MSCMECFA
> > Systems Mangler
> > Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov
> >
> > Voice: (608) 261-5738, Cell: (608) 658-1890
> >
> > Every man has the right to an opinion but no man
> > has a right to be wrong in his facts. Nor, above all,
> > to persist in errors as to facts. Bernard Baruch
> >
> > 
> > From: ToddAndMargo via perl6-users 
> > Sent: Monday, August 24, 2020 9:35 PM
> > To: perl6-users 
> > Subject: print particular lines question
> >
> > Hi All,
> >
> > I seems I should know how to do this, but
> > I am drawing a blank.
> >
> > $ cat Lines.txt | raku -ne 'say $_;'
> > Line 1
> > Line 2
> > Line 3
> > Line 4
> > Line 5
> > Line 6
> > Line 7
> > Line 8
> > Line 9
> > Line 10
> > Line 11
> >
> >
> > I want to print liens 1, 3, and 7.
> >
> > Assigning  `my @x=$_.lines` puts everything into $x[0]
> >
> >
> > Many thanks,
> > -T
> >
>

Re: print particular lines question

[Andy Bach]

Ah, I see, the -n reads a line and then my lines on $*IN starts with the next 
one
C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e "my @x = 
$*IN.lines(); say @x[0,1,7,3]; "
(Line 0 Line 1 Line 7 Line 3)

and so $*IN is the default for lines()
C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -e "my @x = 
lines(); say @x[0,1,7,3]; "
(Line 0 Line 1 Line 7 Line 3)

This hangs, with and without the -n
C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = $*IN.lines(); 
say @x[0,1,7,3]; " lines.txt

Though:
C:\> "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = lines(); say 
@x[0,1,7,3]; " lines.txt
(Line 1 Line 2 Line 8 Line 4)
Cannot do 'get' on a handle in binary mode
  in block  at -e line 1

a

Andy Bach, BS, MSCMECFA
Systems Mangler
Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
Voice: (608) 261-5738, Cell: (608) 658-1890

"The three great problems of computer science:
compiler complexity and 'off-by-one' errors".
https://martinfowler.com/bliki/TwoHardThings.html


From: Andy Bach 
Sent: Tuesday, August 25, 2020 12:18 PM
To: Parrot Raiser <1parr...@gmail.com>
Cc: perl6-users ; ToddAndMargo 
Subject: Re: print particular lines question

On Win10
C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "say 
lines()[1,7,3]; "
(Line 2 Line 8 Line 4)
(Line 11 Nil Nil)

C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "say 
lines()[1,7,3].join(qq~\n~); "
Line 2
Line 8
Line 4
Use of Nil in string context
  in block  at -e line 1
Use of Nil in string context
  in block  at -e line 1
Line 11

and, speaking of that off by one problem ... lines.txt does start with "line 0"
C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = 
$*IN.lines(); say @x[0,1,7,3]; "
(Line 1 Line 2 Line 8 Line 4)

a

Andy Bach, BS, MSCMECFA
Systems Mangler
Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
Voice: (608) 261-5738, Cell: (608) 658-1890

"The three great problems of computer science:
compiler complexity and 'off-by-one' errors".
https://martinfowler.com/bliki/TwoHardThings.html


From: Parrot Raiser <1parr...@gmail.com>
Sent: Tuesday, August 25, 2020 11:22 AM
To: Andy Bach 
Cc: perl6-users ; ToddAndMargo 
Subject: Re: print particular lines question

That will golf a little (and improve it) to:

$ raku -e '.say for lines()[3,2,5]' lines.txt

but you have to remember that it's zero-based. I used the first sample
file and got
Line 4
Line 3
Line 6

"The three great problems of computer science: compiler complexity and
'off-by-one' errors".


On 8/25/20, Andy Bach  wrote:
>> Assigning  `my @x=$_.lines` puts everything into $x[0]
>
> Trying this on windows
>
> C:\> raku.exe   -e "my @x = 'lines.txt'.IO.lines; say
> @x[1,7,3].join(qq~\n~); "
> Line 1
> Line 7
> Line 3
>
> or
> C:\> raku.exe -e " say 'lines.txt'.IO.lines[1,7,3].join(qq~\n~); "
> Line 1
> Line 7
> Line 3
>
> a
>
> Andy Bach, BS, MSCMECFA
> Systems Mangler
> Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
> Voice: (608) 261-5738, Cell: (608) 658-1890
>
> Every man has the right to an opinion but no man
> has a right to be wrong in his facts. Nor, above all,
> to persist in errors as to facts. Bernard Baruch
>
> 
> From: ToddAndMargo via perl6-users 
> Sent: Monday, August 24, 2020 9:35 PM
> To: perl6-users 
> Subject: print particular lines question
>
> Hi All,
>
> I seems I should know how to do this, but
> I am drawing a blank.
>
> $ cat Lines.txt | raku -ne 'say $_;'
> Line 1
> Line 2
> Line 3
> Line 4
> Line 5
> Line 6
> Line 7
> Line 8
> Line 9
> Line 10
> Line 11
>
>
> I want to print liens 1, 3, and 7.
>
> Assigning  `my @x=$_.lines` puts everything into $x[0]
>
>
> Many thanks,
> -T
>

Re: print particular lines question

[Andy Bach]

On Win10
C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "say 
lines()[1,7,3]; "
(Line 2 Line 8 Line 4)
(Line 11 Nil Nil)

C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "say 
lines()[1,7,3].join(qq~\n~); "
Line 2
Line 8
Line 4
Use of Nil in string context
  in block  at -e line 1
Use of Nil in string context
  in block  at -e line 1
Line 11

and, speaking of that off by one problem ... lines.txt does start with "line 0"
C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe"   -ne "my @x = 
$*IN.lines(); say @x[0,1,7,3]; "
(Line 1 Line 2 Line 8 Line 4)

a

Andy Bach, BS, MSCMECFA
Systems Mangler
Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
Voice: (608) 261-5738, Cell: (608) 658-1890

"The three great problems of computer science:
compiler complexity and 'off-by-one' errors".
https://martinfowler.com/bliki/TwoHardThings.html


From: Parrot Raiser <1parr...@gmail.com>
Sent: Tuesday, August 25, 2020 11:22 AM
To: Andy Bach 
Cc: perl6-users ; ToddAndMargo 
Subject: Re: print particular lines question

That will golf a little (and improve it) to:

$ raku -e '.say for lines()[3,2,5]' lines.txt

but you have to remember that it's zero-based. I used the first sample
file and got
Line 4
Line 3
Line 6

"The three great problems of computer science: compiler complexity and
'off-by-one' errors".


On 8/25/20, Andy Bach  wrote:
>> Assigning  `my @x=$_.lines` puts everything into $x[0]
>
> Trying this on windows
>
> C:\> raku.exe   -e "my @x = 'lines.txt'.IO.lines; say
> @x[1,7,3].join(qq~\n~); "
> Line 1
> Line 7
> Line 3
>
> or
> C:\> raku.exe -e " say 'lines.txt'.IO.lines[1,7,3].join(qq~\n~); "
> Line 1
> Line 7
> Line 3
>
> a
>
> Andy Bach, BS, MSCMECFA
> Systems Mangler
> Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
> Voice: (608) 261-5738, Cell: (608) 658-1890
>
> Every man has the right to an opinion but no man
> has a right to be wrong in his facts. Nor, above all,
> to persist in errors as to facts. Bernard Baruch
>
> 
> From: ToddAndMargo via perl6-users 
> Sent: Monday, August 24, 2020 9:35 PM
> To: perl6-users 
> Subject: print particular lines question
>
> Hi All,
>
> I seems I should know how to do this, but
> I am drawing a blank.
>
> $ cat Lines.txt | raku -ne 'say $_;'
> Line 1
> Line 2
> Line 3
> Line 4
> Line 5
> Line 6
> Line 7
> Line 8
> Line 9
> Line 10
> Line 11
>
>
> I want to print liens 1, 3, and 7.
>
> Assigning  `my @x=$_.lines` puts everything into $x[0]
>
>
> Many thanks,
> -T
>

Re: print particular lines question

[Parrot Raiser]

That will golf a little (and improve it) to:

$ raku -e '.say for lines()[3,2,5]' lines.txt

but you have to remember that it's zero-based. I used the first sample
file and got
Line 4
Line 3
Line 6

"The three great problems of computer science: compiler complexity and
'off-by-one' errors".


On 8/25/20, Andy Bach  wrote:
>> Assigning  `my @x=$_.lines` puts everything into $x[0]
>
> Trying this on windows
>
> C:\> raku.exe   -e "my @x = 'lines.txt'.IO.lines; say
> @x[1,7,3].join(qq~\n~); "
> Line 1
> Line 7
> Line 3
>
> or
> C:\> raku.exe -e " say 'lines.txt'.IO.lines[1,7,3].join(qq~\n~); "
> Line 1
> Line 7
> Line 3
>
> a
>
> Andy Bach, BS, MSCMECFA
> Systems Mangler
> Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
> Voice: (608) 261-5738, Cell: (608) 658-1890
>
> Every man has the right to an opinion but no man
> has a right to be wrong in his facts. Nor, above all,
> to persist in errors as to facts. Bernard Baruch
>
> ________
> From: ToddAndMargo via perl6-users 
> Sent: Monday, August 24, 2020 9:35 PM
> To: perl6-users 
> Subject: print particular lines question
>
> Hi All,
>
> I seems I should know how to do this, but
> I am drawing a blank.
>
> $ cat Lines.txt | raku -ne 'say $_;'
> Line 1
> Line 2
> Line 3
> Line 4
> Line 5
> Line 6
> Line 7
> Line 8
> Line 9
> Line 10
> Line 11
>
>
> I want to print liens 1, 3, and 7.
>
> Assigning  `my @x=$_.lines` puts everything into $x[0]
>
>
> Many thanks,
> -T
>

Re: print particular lines question

[Andy Bach]

> Assigning  `my @x=$_.lines` puts everything into $x[0]

Trying this on windows

C:\> raku.exe   -e "my @x = 'lines.txt'.IO.lines; say @x[1,7,3].join(qq~\n~); "
Line 1
Line 7
Line 3

or
C:\> raku.exe -e " say 'lines.txt'.IO.lines[1,7,3].join(qq~\n~); "
Line 1
Line 7
Line 3

a

Andy Bach, BS, MSCMECFA
Systems Mangler
Internet: andy_b...@wiwb.uscourts.gov<mailto:andy_b...@wiwb.uscourts.gov>
Voice: (608) 261-5738, Cell: (608) 658-1890

Every man has the right to an opinion but no man
has a right to be wrong in his facts. Nor, above all,
to persist in errors as to facts. Bernard Baruch


From: ToddAndMargo via perl6-users 
Sent: Monday, August 24, 2020 9:35 PM
To: perl6-users 
Subject: print particular lines question

Hi All,

I seems I should know how to do this, but
I am drawing a blank.

$ cat Lines.txt | raku -ne 'say $_;'
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11


I want to print liens 1, 3, and 7.

Assigning  `my @x=$_.lines` puts everything into $x[0]


Many thanks,
-T

Re: print particular lines question

[ToddAndMargo via perl6-users]

On Mon, Aug 24, 2020 at 11:08 PM ToddAndMargo via perl6-users
 wrote:


On 2020-08-24 19:35, ToddAndMargo via perl6-users wrote:

Hi All,

I seems I should know how to do this, but
I am drawing a blank.

$ cat Lines.txt | raku -ne 'say $_;'
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11


I want to print liens 1, 3, and 7.

Assigning  `my @x=$_.lines` puts everything into $x[0]


Many thanks,
-T


This is what I have so far:

$ cat Lines.txt
Line 0
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11

$ cat Lines.txt | raku -e ' my @x=$*IN.lines; for @x[3,2,5] {say $_};'
Line 3
Line 2
Line 5


is there a quicker way to get to the point?

Many thanks,
-T


On 2020-08-24 20:24, Curt Tilmes wrote:

$ cat Lines.txt | raku -e '.say for lines()[3,2,5]'


Love it!  Thank you!

Re: print particular lines question

[Curt Tilmes]

$ cat Lines.txt | raku -e '.say for lines()[3,2,5]'

On Mon, Aug 24, 2020 at 11:08 PM ToddAndMargo via perl6-users
 wrote:
>
> On 2020-08-24 19:35, ToddAndMargo via perl6-users wrote:
> > Hi All,
> >
> > I seems I should know how to do this, but
> > I am drawing a blank.
> >
> > $ cat Lines.txt | raku -ne 'say $_;'
> > Line 1
> > Line 2
> > Line 3
> > Line 4
> > Line 5
> > Line 6
> > Line 7
> > Line 8
> > Line 9
> > Line 10
> > Line 11
> >
> >
> > I want to print liens 1, 3, and 7.
> >
> > Assigning  `my @x=$_.lines` puts everything into $x[0]
> >
> >
> > Many thanks,
> > -T
>
> This is what I have so far:
>
> $ cat Lines.txt
> Line 0
> Line 1
> Line 2
> Line 3
> Line 4
> Line 5
> Line 6
> Line 7
> Line 8
> Line 9
> Line 10
> Line 11
>
> $ cat Lines.txt | raku -e ' my @x=$*IN.lines; for @x[3,2,5] {say $_};'
> Line 3
> Line 2
> Line 5
>
>
> is there a quicker way to get to the point?
>
> Many thanks,
> -T

Re: print particular lines question

[ToddAndMargo via perl6-users]

On 2020-08-24 19:35, ToddAndMargo via perl6-users wrote:

Hi All,

I seems I should know how to do this, but
I am drawing a blank.

$ cat Lines.txt | raku -ne 'say $_;'
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11


I want to print liens 1, 3, and 7.

Assigning  `my @x=$_.lines` puts everything into $x[0]


Many thanks,
-T


This is what I have so far:

$ cat Lines.txt
Line 0
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11

$ cat Lines.txt | raku -e ' my @x=$*IN.lines; for @x[3,2,5] {say $_};'
Line 3
Line 2
Line 5


is there a quicker way to get to the point?

Many thanks,
-T

print particular lines question

[ToddAndMargo via perl6-users]

Hi All,

I seems I should know how to do this, but
I am drawing a blank.

$ cat Lines.txt | raku -ne 'say $_;'
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11


I want to print liens 1, 3, and 7.

Assigning  `my @x=$_.lines` puts everything into $x[0]


Many thanks,
-T