Current file name used by $*ARGS filehandle
Brian D Foy
Is there going to be a Perl 6 equivalent to $ARGV (the current filename
for the ARGV filehandle)?
This is something I wanted to use in an example in the Learning Perl 6
filehandles chapter:
Larry Wall
: Is there going to be a Perl 6 equivalent to $ARGV (the current filename
: for the ARGV filehandle)?
Hmm, well, we did away with unsigiled filehandles, and renamed @ARGV
to @*ARGS, so $*ARGS is presumably the magical filehandle, which means
it can't really serve as the filename at the same time. So assuming
that any filehandle knows the name of its file (if available), it'd
probably be available via a method like $ARGS.name or some such.
Larry
Brian D Foy
<la...@wall.org> wrote:
$ARGS.name seems reasonable enough, and the method could be very handle
for other things that use filehandles too. However, until it shows up
in a synopsis, I'll assume you're just thinking aloud rather than
making a decision. :)
Andrew Shitov
To avoid any uncertainty: the subject is a parody for similar
discussion on perl6-internals@ about Parrot.
=FOREWORD
What I want to say is that after N years of developing Perl 6 we do
not have a practical (P in Perl stands for Practical) tool which can
work in real life.
Even worse: today there is no way to speed up the interpreter - it is
good for parsing the language but is very slow for real applications.
(mod_pugs is not the case while there is no command-line tool).
=EXPLANATION
We have Pugs to play with. We have no tool to run with.
Current Pugs have options to compile the programme into several
intermediate languages, for example PIR:
You can
pugs -CPIR helloworld.pl > helloworld.pir
But you cannot later do this:
pugs -BPIR helloworld.pir
Standalone parrot does not help.
=WHAT IS TO BE DONE
What is nedded is a very simple step: complete the Pugs compiler so
that it could provide good PASM (PIR). Going this way we will achieve
the main goal: it will be possible to use hi-speed applications
written in Perl 6 today. No care the language itself is not fully
standardized.
It will change the status of 'conception' and 'project'
to 'utilizing' and 'using'.
=CUT
A bit of fun is that three years ago the situation was better: language
was more poor, the tools for more pure. In April of 2004 I made
a toy server with demos of how real Perl 6 works on a web-server. There
was a bit of examples with comments in Russian that were written on
real Perl 6 of that day, compiled into Parrot bytecode (.pbc) and run
on Apache under Parrot virtual machine. I cannot do the same with
today's instrumentary (or maybe I do not know how to?).
Thank you for understanding :-)
--
Andrew Shitov
______________________________________________________________________
an...@shitov.ru | http://www.shitov.ru
Chromatic
> What is nedded is a very simple step:
Contributors.
-- c
Thomas Wittek
> On Thursday 03 May 2007 03:06:43 Andrew Shitov wrote:
>> What is nedded is a very simple step:
> Contributors.
And to attract contributors, you have to have a convincing vision.
I'm not sure, if the (current) Perl6 specs are convincing enough to
attract the developers out there.
Sure there are a lot of great ideas. But imho Perl6 still has quite some
deficiencies, that are criticized very often for Perl5.
<digressing>
I'm only a distant observer of the Perl6 design process, so I might not
be in the position to criticize Perl6.
On the other hand, a distant view might be insightful.
This is not intended to be a provocation.
But I also think that there is a great opportunity to make _big_ changes
to Perl to be even more competitive.
But maybe Perl6 is probably too far defined to encounter big changes in
some critical aspects.
As Ruby and Python are getting more and more attraction [1][2] I think
they do something right, that Perl doesn't.
What I think where both (especially Python) do better is in readable code.
What makes Perl hard to read is the excessive use of special characters
(/\W/).
In my opinion, reducing the use of those characters would make Perl a
lot easier to read and also easier to write.
Global variables with cryptic names, that no beginner can make any sense
of by reading it. And after not working with "$<" for some months I
can't remember it either, although I've got quite some Perl experience.
Additionally I'm not a friend of sigils: Typing them is relatively
painful, for reading there is no advantage if you use an editor with
decent syntax highlighting and the code looks more cryptic. The answer
in Perl6 are twigils, great... One step backwards in my optinion.
Most programming languages
/C(++|#)?|Java(Script)?|Python|Ruby|Groovy/... don't need them. The only
obvious advantage of using sigils is variable interpolation in strings.
But that could easily be done only in strings without the need to put a
$ in front of each and every variable name in the rest of the code.
I would also like semicolons to be optional. There are far more cases of
single line statements than multiline statements. So you would save
quite some characters, when the semicolon would be optional and you
could concatenate multiline statements with e.g. a backslash.
Some say that there are too much operators in Perl(6). I partially
agree. I don't like the implicit type casting forced by the operators
(== int / eq string). That's harder to learn and remember. Harder to
read also.
I really like the Python way of doing it: Set the variables type on the
assignment and remember it. The (fewer) operators now work according to
the type of the operands. No implicit (and error prone) type casting.
That way seems to be the best compromise of easiness and type safety.
I could continue on that, but I've already written too much...
[1] http://radar.oreilly.com/archives/2007/05/state_of_the_co_6.html
[2] http://www.google.com/trends?q=perl%2C+python+-snake%2C+ruby
</digressing>
People not only want code that _is_ sexy, but they also want it to
_look_ sexy.
--
Thomas Wittek
http://gedankenkonstrukt.de/
Jabber: strea...@jabber.i-pobox.net
Moritz Lenz
> chromatic schrieb:
>> On Thursday 03 May 2007 03:06:43 Andrew Shitov wrote:
>>> What is nedded is a very simple step:
>> Contributors.
>
> And to attract contributors, you have to have a convincing vision.
> I'm not sure, if the (current) Perl6 specs are convincing enough to
> attract the developers out there.
I think they are ;-)
> But I also think that there is a great opportunity to make _big_ changes
> to Perl to be even more competitive.
I don't think that there is space for the changes you are implying in
the following paragraphs. Small changes are acceptable, of course.
> But maybe Perl6 is probably too far defined to encounter big changes in
> some critical aspects.
Right ;-)
> As Ruby and Python are getting more and more attraction [1][2] I think
> they do something right, that Perl doesn't.
> What I think where both (especially Python) do better is in readable code.
>
> What makes Perl hard to read is the excessive use of special characters
> (/\W/).
I disagree: The make it look ugly, but not hard to read.
> Global variables with cryptic names, that no beginner can make any sense
> of by reading it. And after not working with "$<" for some months I
> can't remember it either, although I've got quite some Perl experience.
Well, most of them are gone or renamed to more readable ones in p6.
> Additionally I'm not a friend of sigils:
Then you shouldn't program in perl. Really.
> I would also like semicolons to be optional.
Most people don't ;-).
> I really like the Python way of doing it: Set the variables type on the
> assignment and remember it. The (fewer) operators now work according to
> the type of the operands. No implicit (and error prone) type casting.
> That way seems to be the best compromise of easiness and type safety.
Well, if you like the python way, feel free to code in python.
Perhaps some day it will be possible to mix them:
use python;
# Write python code here
Don't get me wrong, there's nothing bad in writing some critics, but
yours is impossible to realize in Perl 6, and therefore are it's hard to
call it constructive.
Cheers,
Moritz
--
Moritz Lenz
http://moritz.faui2k3.org/ | http://perl-6.de/
Chromatic
> What makes Perl hard to read is the excessive use of special characters
> (/\W/).
It also makes Mandarin and other ideographic languages impossible to read. As
evidence I admit that, though I am very smart, *I* can't read them.
(Try to ignore the billion-plus people who can.)
> Global variables with cryptic names, that no beginner can make any sense
> of by reading it. And after not working with "$<" for some months I
> can't remember it either, although I've got quite some Perl experience.
Most of those have gone away.
> Additionally I'm not a friend of sigils:
I'm not a friend of potential conflicts between built-in operators and my
identifier names (and especially the conflicts between scalar, aggregate,
type, and function names).
> I would also like semicolons to be optional. There are far more cases of
> single line statements than multiline statements. So you would save
> quite some characters, when the semicolon would be optional and you
> could concatenate multiline statements with e.g. a backslash.
When (smart) people talk about Python's whitespace problem, they don't mean
*horizontal* whitespace.
> Some say that there are too much operators in Perl(6). I partially
> agree.
That's like saying there are too many function calls in Scheme. Perl's an
operator-oriented language!
> People not only want code that _is_ sexy, but they also want it to
> _look_ sexy.
You'll have to find me more than a handful of Dylan hackers to start to
convince me of that!
-- c
Herbert Breunung
> And to attract contributors, you have to have a convincing vision.
right
please make a decision for you to program in a language that has fame
or one that you like most. as moritz said the special variables are now
better sorted and some changes you write about are too far from perls
basic principles, i thank that would not be perl anymore. but even for
demands like yours it is thought as 2 or 3 lisp-style macros could
turn perl6 into something your seems to want. except that one with
type recognition of course which i cant think of how to make this work
with an macro.
but hey since parrot also will read python you would not run too far
if you try python. i think you could only win if you try it. maybe youll find
problems with python you didnt thought abd be than better informed
of or found your favoured programming lang.
best
herbert
> I'm only a distant observer of the Perl6 design process, so I might not
> be in the position to criticize Perl6.
> On the other hand, a distant view might be insightful.
> This is not intended to be a provocation.
> But I also think that there is a great opportunity to make _big_ changes
> to Perl to be even more competitive.
> But maybe Perl6 is probably too far defined to encounter big changes in
> some critical aspects.
>
> As Ruby and Python are getting more and more attraction [1][2] I think
> they do something right, that Perl doesn't.
> What I think where both (especially Python) do better is in readable code.
>
> What makes Perl hard to read is the excessive use of special characters
> (/\W/).
> In my opinion, reducing the use of those characters would make Perl a
> lot easier to read and also easier to write.
> Global variables with cryptic names, that no beginner can make any sense
> of by reading it. And after not working with "$<" for some months I
> can't remember it either, although I've got quite some Perl experience.
>
> Additionally I'm not a friend of sigils: Typing them is relatively
> painful, for reading there is no advantage if you use an editor with
> decent syntax highlighting and the code looks more cryptic. The answer
> in Perl6 are twigils, great... One step backwards in my optinion.
> Most programming languages
> /C(++|#)?|Java(Script)?|Python|Ruby|Groovy/... don't need them. The only
> obvious advantage of using sigils is variable interpolation in strings.
> But that could easily be done only in strings without the need to put a
> $ in front of each and every variable name in the rest of the code.
>
> I would also like semicolons to be optional. There are far more cases of
> single line statements than multiline statements. So you would save
> quite some characters, when the semicolon would be optional and you
> could concatenate multiline statements with e.g. a backslash.
>
> Some say that there are too much operators in Perl(6). I partially
> agree. I don't like the implicit type casting forced by the operators
> (== int / eq string). That's harder to learn and remember. Harder to
> read also.
> I really like the Python way of doing it: Set the variables type on the
> assignment and remember it. The (fewer) operators now work according to
> the type of the operands. No implicit (and error prone) type casting.
> That way seems to be the best compromise of easiness and type safety.
>
> I could continue on that, but I've already written too much...
>
> [1] http://radar.oreilly.com/archives/2007/05/state_of_the_co_6.html
> [2] http://www.google.com/trends?q=perl%2C+python+-snake%2C+ruby
>
> </digressing>
>
> People not only want code that _is_ sexy, but they also want it to
> _look_ sexy.
>
> --
> Thomas Wittek
> http://gedankenkonstrukt.de/
> Jabber: strea...@jabber.i-pobox.net
>
______________________________________________________________________
XXL-Speicher, PC-Virenschutz, Spartarife & mehr: Nur im WEB.DE Club!
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Thomas Wittek
>> What makes Perl hard to read is the excessive use of special characters
>> (/\W/).
>
> I disagree: The make it look ugly, but not hard to read.
Even if it's "only" ugly: To what advantage? I don't think ugliness is a
good characteristic of a programming language.
>> Global variables with cryptic names, that no beginner can make any sense
>> of by reading it. And after not working with "$<" for some months I
>> can't remember it either, although I've got quite some Perl experience.
>
> Well, most of them are gone or renamed to more readable ones in p6.
I hope so. I could only find the counterparts for __PACKAGE__ etc. in
S02. I didn't find the one for e.g. $<.
>> Additionally I'm not a friend of sigils:
>
> Then you shouldn't program in perl. Really.
Reason? I still haven't seen a good justification for sigils.
To allow arrays and scalars and subs to have the same name (besides the
sigil) although they have different content? No good idea I think.
I also can't remember that I ever named a variable like a "reserved
word" or operator. And even if I could, I'd consider it to be bad style.
>> I would also like semicolons to be optional.
>
> Most people don't ;-).
Oh, really? Source? :)
I think they were invented to allow easier parsing and not easier coding.
E.g. in JavaScript, Python, Ruby and Groovy they are optional or even
don't exist. As I said, there are much more cases where you wouldn't
need them but have to write them than vice versa.
Optional semicolons save keystrokes, eye pain and stupid syntactic
errors. And if you still like them, you could just use them, which is
the definition of "optional".
>> I really like the Python way of doing it: Set the variables type on the
>> assignment and remember it. The (fewer) operators now work according to
>> the type of the operands. No implicit (and error prone) type casting.
>> That way seems to be the best compromise of easiness and type safety.
>
> Well, if you like the python way, feel free to code in python.
Oh, if I didn't like Perl, why should I care about posting my ideas here?
Perl has stolen the largest part of the language from other languages.
Why not do so again by adopting good ideas.
> Don't get me wrong, there's nothing bad in writing some critics, but
> yours is impossible to realize in Perl 6
Admittedly I'm much too late and I didn't expect applause for my critics
-- but at least I hoped to get a discussion based on arguments.
> and therefore are it's hard to call it constructive.
Unfortunately I already thought this. Even if everyone agreed that
sigils (or forced semicolons, or tons of operators, ...) are more bad
than good (and this seems like persuading the pope to allow homosexual
muslims to marry with priests) the design process is probably too far to
introduce such dramatic changes.
Sadly.
Andy Armstrong
> I also can't remember that I ever named a variable like a "reserved
> word" or operator. And even if I could, I'd consider it to be bad
> style.
How did you know which reserved words and operators were going to be
introduced in the future so you could avoid them all?
--
Andy Armstrong, hexten.net
Thomas Wittek
>> Global variables with cryptic names, that no beginner can make any sense
>> of by reading it. And after not working with "$<" for some months I
>> can't remember it either, although I've got quite some Perl experience.
>
> Most of those have gone away.
Oh, some someone must agree that word characters might be the better choice.
As I wrote Moritz, I could only find the replacements for __PACKAGE__
and alike. Additionally it would be very nice to group them in packages.
>> Additionally I'm not a friend of sigils:
>
> I'm not a friend of potential conflicts between built-in operators and my
> identifier names (and especially the conflicts between scalar, aggregate,
> type, and function names).
As I partially wrote Moritz, I
a) don't think that it's the case very often. you have to write the
sigil a thousand times where it wouldn't be useful for only 1 case where
you'd have a name conflict.
b) even if there would be a conflict, it might be considered bad style
to use identical identifiers (besides the sigil) for different things
(vars/objects/subs/operators/...).
>> I would also like semicolons to be optional.
>
> When (smart) people talk about Python's whitespace problem, they don't mean
> *horizontal* whitespace.
I'm not much into Python. But as at least Ruby, Python, JavaScript,
Groovy and Lua (which all are relatively young languages) don't force
you to write semicolons.
So semicolons don't seem to be the best invention since sliced bread.
There should be extra-syntax for the rare cases (multiline) and not for
the common ones.
>> Some say that there are too much operators in Perl(6). I partially
>> agree.
>
> That's like saying there are too many function calls in Scheme. Perl's an
> operator-oriented language!
And it should be. I really like the expressive power of most of the
operators. Especially the new zip/junction/reduce/smart-match ones.
But I don't like doing implicit type casting with operators.
It's even discouraged in Perl5 as we have a warning for that.
So maybe it'd be a good idea to completely drop it.
>> People not only want code that _is_ sexy, but they also want it to
>> _look_ sexy.
At least almost everyone to whom I said, that I do most work in Perl,
responded with some sentence containing the word "ugly" or "unreadable".
To get away from that image, it's neccessary to do some radical changes
I think.
Andy Armstrong
> How did C, C#, Java, Ruby, Python, Lua, JavaScript, Visual Basic,
> etc. know?
> They didn't.
> If there is a new release, you always have to check if your code
> still runs.
I think that may be the point I'm making.
--
Andy Armstrong, hexten.net
Thomas Wittek
How did C, C#, Java, Ruby, Python, Lua, JavaScript, Visual Basic, etc. know?
They didn't.
If there is a new release, you always have to check if your code still runs.
--
Thomas Wittek
> please make a decision for you to program in a language [..]
> [..] try python. [..]
Oh, just because I think that they've some smart design decisions?
Why not steal them?
BTW: Why do so much people say "go away if you don't like it" instead of
being open for ideas and discussing them from a neutral point of view?
Herbert Breunung
> herbert breunung schrieb:
> > please make a decision for you to program in a language [..]
> > [..] try python. [..]
>
> Oh, just because I think that they've some smart design decisions?
> Why not steal them?
>
> BTW: Why do so much people say "go away if you don't like it" instead of
> being open for ideas and discussing them from a neutral point of view?
you ignore what i wrote. im glad if you stay and keep on ask important questions
but please recognise that there are some core decisions that define the language
called perl, and when we change them its no longer perl. so please dont feel offended
to me its a matter of logic and practibality.
and to me it maybe sometime usefull dont write as much ";" but keep out sigils
i definitly dont like because it became much harder readable to me and the whole
subject of twigils and siginiture sigils goes down the toilet whenn we throw that
one away.
so i hope you understand me now better
all best
herbert
_____________________________________________________________________
Der WEB.DE SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen!
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Mark J. Reed
if so many people think it..." Uh-uh. Instinctive reactions can be
both universal and incorrect...and I think that's what this is. At
least, among those who have even bothered to look into Perl instead of
just repeating FUD. As for the rest, nothing we do to P6 will
overcome the default "Perl sucks" reaction from such bigots. Better
to make it a powerful language with a compelling functional reason to
use it; if we succeed, we can maybe start to win back some mindshare
and undo the rep damage caused by the cgi explosion.
--
Mark J. Reed <mark...@mail.com>
Thomas Wittek
Your point is that you don't have one?
Do you believe, that new keywords are the only cause of breaking
backwards compatibility? I don't think so.
So you rely on testing your code anyway. Sigils won't save you from that.
John Macdonald
> Andy Armstrong schrieb:
> >On 14 May 2007, at 12:31, Thomas Wittek wrote:
> >>How did C, C#, Java, Ruby, Python, Lua, JavaScript, Visual Basic, etc.
> >>know?
> >>They didn't.
> >>If there is a new release, you always have to check if your code still
> >>runs.
> >
> >I think that may be the point I'm making.
>
> Your point is that you don't have one?
> Do you believe, that new keywords are the only cause of breaking
> backwards compatibility? I don't think so.
> So you rely on testing your code anyway. Sigils won't save you from that.
Back in the 90's I was with a company that had a 20K line
perl program. We would provide a copy of perl as part of the
program suite, so that we could control which version was
being used for our software and when it was upgraded while
still allowing the customer to have their own version of perl
that they could upgrade on their own schedule. Before any perl
upgrade was built into our suite, we would of course test it
extensivily to ensure that all of the code was still compatible.
Until the perl4->perl5 change, there was never any problem -
Larry is a wizard at adding totally new concepts and features
in a way that just "happens" to include all of the old usage
bits as a special case that falls magically out of the new,
enhanced, more coherent whole. But there is no way that this
would have been possible without the distinction between named
operators and variables provided by sigils. Removing the sigil
on a function call (it used to always be written &sub(args...))
did, I think, lead to the difficulty in perl5 where it became
difficult to add new keyword operators to the language - because
they could conflict with subroutine names in existing code.
Needless to say, that level of dependable upgradability without
requiring code rewrites was considered to e a huge benefit of
using perl for our company.
(For the record, we delayed converting from perl4 to perl5 for
many years, woried about the possibility of subtle problems
arising from the massive changes that had been made to the
language. When I finally tried it out, there were only a few
changes that really affected us. I had the code converted in
about two weeks, although we then ran it in parallel with the
old code for about two months before accepting that nothing
tricky had snuck in.)
--
Chromatic
> BTW: Why do so much people say "go away if you don't like it" instead of
> being open for ideas and discussing them from a neutral point of view?
Perhaps you're not a native English speaker, but running into the room and
saying "Perl 6 doesn't have a compelling vision", "Everyone thinks Perl is
ugly", and "Python and Ruby are doing things better than Perl 6" is *not* the
way to start a friendly and neutral discussion, as if a sane, calm, neutral
discussion of programming language designs and tradeoffs were possible.
-- c
Chromatic
> > I'm not a friend of potential conflicts between built-in operators and my
> > identifier names (and especially the conflicts between scalar, aggregate,
> > type, and function names).
> As I partially wrote Moritz, I
> a) don't think that it's the case very often. you have to write the
> sigil a thousand times where it wouldn't be useful for only 1 case where
> you'd have a name conflict.
> b) even if there would be a conflict, it might be considered bad style
> to use identical identifiers (besides the sigil) for different things
> (vars/objects/subs/operators/...).
theproblemlinguisticallyspeakingisthatsometimespunctuationishighlyimportant\
fromareadabilitystandpointyoumaynotliketheuseofspacescommasdashesupper\
casinghyphensandperiodsbutitmakesatremendousdifferencetoreadabilitywhether\
youlikeitornotasitmaybebadstyleifyoudontputspacesbetweentwowordsandtheresult\
lookslikeawordthatsomeonemaydefineinthefuture
There *are* a few linguists involved in Perl.
> So semicolons don't seem to be the best invention since sliced bread.
> There should be extra-syntax for the rare cases (multiline) and not for
> the common ones.
Somehow English seems to get by with periods at the ends of statements, though
almost no one pronounces them.
> But I don't like doing implicit type casting with operators.
> It's even discouraged in Perl5 as we have a warning for that.
> So maybe it'd be a good idea to completely drop it.
I can't really see that changing DWIM to DWTWM is anything but a step
backwards in Perlishness.
> >> People not only want code that _is_ sexy, but they also want it to
> >> _look_ sexy.
> At least almost everyone to whom I said, that I do most work in Perl,
> responded with some sentence containing the word "ugly" or "unreadable".
> To get away from that image, it's neccessary to do some radical changes
> I think.
I agree. You need less ignorant colleagues. I'm not sure Perl 6 can fix
that.
By the way, I'm still waiting to meet your cadre of Dylan hackers.
-- c
Moritz Lenz
> BTW: Why do so much people say "go away if you don't like it" instead of
> being open for ideas and discussing them from a neutral point of view?
because the design process of perl 6 started long time ago, and if we
incooperate major changes to it, no implementation will ever finish.
I don't think most of are not open to new point of views, but regard p6
they just don't help atm.
Moritz Lenz
> Moritz Lenz schrieb:
>>> What makes Perl hard to read is the excessive use of special characters
>>> (/\W/).
>>
>> I disagree: The make it look ugly, but not hard to read.
>
> Even if it's "only" ugly: To what advantage? I don't think ugliness is a
> good characteristic of a programming language.
In fact it makes the code easier to read. At least to me.
The other day I had a lot of work to do with matlab code, and it just
sucked. No variables where declared, and therefore I had no type
information. I didn't knew if arguments passed to functions were
arrays/matrices or scalars, and sigils would have helped very much.
And don't say "but a good IDE.." - I didn't have one. No language should
depend on its IDE's syntax hilighting.
>>> I would also like semicolons to be optional.
>>
>> Most people don't ;-).
>
> Oh, really? Source? :)
I paraphrased Larry Wall. Iirc it was "everybody wants the semicolon" or
something - correct me if I'm wrong.
> I think they were invented to allow easier parsing and not easier coding.
I think the p6 grammar is so complex that you couldn't do it without a
statement terminator, be it a semicolon or a newline. And we know that
you prefer the newline, I (and it seems, many other) do prefer semicolons.
> E.g. in JavaScript, Python, Ruby and Groovy they are optional or even
> don't exist.
most languages don't allow you to call a function without parentheses.
if you have
foo bar
without a statement termination, you can't know if thats
foo(bar()),
or
foo()
bar()
whereas if you force the parentheses, it is unambigous anyway.
Which explains why languages with simpler syntax can well live without
the semicolon.
>>> I really like the Python way of doing it: Set the variables type on the
>>> assignment and remember it. The (fewer) operators now work according to
>>> the type of the operands. No implicit (and error prone) type casting.
>>> That way seems to be the best compromise of easiness and type safety.
>>
>> Well, if you like the python way, feel free to code in python.
>
> Oh, if I didn't like Perl, why should I care about posting my ideas here?
> Perl has stolen the largest part of the language from other languages.
> Why not do so again by adopting good ideas.
because, as was pointed out earlier, huge changes
a) delay implementation significantly and
b) change the character of the language too heavily. We want Perl 6 to
be Perl still.
>> Don't get me wrong, there's nothing bad in writing some critics, but
>> yours is impossible to realize in Perl 6
>
> Admittedly I'm much too late and I didn't expect applause for my critics
> -- but at least I hoped to get a discussion based on arguments.
Most of these issues have been discussed in one way or another, either
on p6l or on use.perl.org. If you really want the arguments, you'll find
most of them.
>> and therefore are it's hard to call it constructive.
>
> Unfortunately I already thought this. Even if everyone agreed that
> sigils (or forced semicolons, or tons of operators, ...) are more bad
> than good (and this seems like persuading the pope to allow homosexual
> muslims to marry with priests) the design process is probably too far to
> introduce such dramatic changes.
Right.
Moritz Lenz
> Thomas Wittek wrote:
>> Moritz Lenz schrieb:
>>> Most people don't ;-).
>> Oh, really? Source? :)
>
> I paraphrased Larry Wall. Iirc it was "everybody wants the semicolon" or
> something - correct me if I'm wrong.
sorry, masak++ pointed out that it was wrong indeed.
Frank Wiles
Thomas Wittek <ma...@gedankenkonstrukt.de> wrote:
> Reason? I still haven't seen a good justification for sigils.
This may not qualify as a "good justification", but it is one I've
discussed with others and rings true for many. Take a look at
actual code written in other languages and you'll find many variable
names that end in things like _ary, _array, _dict, _list, etc. to
denote the type of container it is. Why? Because 'foo' doesn't
tell you what it is, so programmers compensate with 'foo_dict' or
'foo_array' so they don't have to constantly go looking for the
definition.
With Perl you get that plainly visible with one single character at
the beginning of the variable name. You can differentiate what it
is easily, in a consistent way, with only one character.
Personally, I love sigils for this reason alone.
> To allow arrays and scalars and subs to have the same name (besides
> the sigil) although they have different content? No good idea I think.
> I also can't remember that I ever named a variable like a "reserved
> word" or operator. And even if I could, I'd consider it to be bad
> style.
Much like your argument about naming variables after reserved
words, I see naming an array, scalar, and a sub the same to be
bad style.
---------------------------------
Frank Wiles <fr...@wiles.org>
http://www.wiles.org
---------------------------------
Gabor Szabo
> Removing the sigil
> on a function call (it used to always be written &sub(args...))
> did, I think, lead to the difficulty in perl5 where it became
> difficult to add new keyword operators to the language - because
> they could conflict with subroutine names in existing code.
Actually I think I never understood this issue.
We claim that having the sigils saves us from stepping on our future
feet by making sure keywords of the language are always different
from any variable we might create.
The fact that function don't need a sigil any more and it is even
AFAIK discouraged to be used makes *this* argument mute.
Thought this thread might not be the best place to ask this
I'd be glad to read some explanation about this.
regards
Gabor
Tibor Foeldes
> As Ruby and Python are getting more and more attraction [1][2] I think
> they do something right, that Perl doesn't.
> What I think where both (especially Python) do better is in readable
> code.
>
> What makes Perl hard to read is the excessive use of special characters
> (/\W/).
>
It is in Ruby the same. In Python re.search('\W',foo). Is it
really nicer ?
> In my opinion, reducing the use of those characters would make Perl a
> lot easier to read and also easier to write.
> Global variables with cryptic names, that no beginner can make any sense
> of by reading it. And after not working with "$<" for some months I
> can't remember it either, although I've got quite some Perl experience.
>
>
In Perl6: $*UID (see S02.pod)
> Additionally I'm not a friend of sigils: Typing them is relatively
> painful, for reading there is no advantage if you use an editor with
> decent syntax highlighting and the code looks more cryptic. The answer
> in Perl6 are twigils, great... One step backwards in my optinion.
> Most programming languages
> /C(++|#)?|Java(Script)?|Python|Ruby|Groovy/... don't need them. The only
> obvious advantage of using sigils is variable interpolation in strings.
> But that could easily be done only in strings without the need to put a
> $ in front of each and every variable name in the rest of the code.
>
>
Perl is a language with sigils. We must see it more penetrating ! The
advantages of sigils in Perl are overall, by item access in structures,
by the flexibility of subroutine calls, interpolation , global
variables, ....
Perl wants separate variables from other language structures . Perl
without sigils is not Perl more. Perl6 in this regards is really to
late for you :-)
> I would also like semicolons to be optional. There are far more cases of
> single line statements than multiline statements. So you would save
> quite some characters, when the semicolon would be optional and you
> could concatenate multiline statements with e.g. a backslash.
>
> Some say that there are too much operators in Perl(6). I partially
> agree. I don't like the implicit type casting forced by the operators
> (== int / eq string). That's harder to learn and remember. Harder to
> read also.
Operators are only another format ( nice ) of functions.
> I really like the Python way of doing it: Set the variables type on the
> assignment and remember it. The (fewer) operators now work according to
> the type of the operands. No implicit (and error prone) type casting.
> That way seems to be the best compromise of easiness and type safety.
> I could continue on that, but I've already written too much...
>
"use warnings" is helping you !
And you can always make explicit type conversion. That does mean
explicit :-) . But you must type something more.
The only builtin implicit type casting in Perl is this numeric / string
conversion and it is fairly obvious and absolutely not error-prone.
> [1] http://radar.oreilly.com/archives/2007/05/state_of_the_co_6.html
> [2] http://www.google.com/trends?q=perl%2C+python+-snake%2C+ruby
>
>
These reports are fairly special. These are not about popularity of a
programming language , but
how many books O'Reilly sold, and how many were googled. What about is
not clear. Maybe waiting for Perl6 ?
In place of contributing? Searching for redemption ?
> People not only want code that _is_ sexy, but they also want it to
> _look_ sexy.
>
Sex is oftentimes perversion ;-) Well, natural selection. Survives the
fittest idea , not necessarily the sexiest look.
Tibor
Ryan Richter
In Perl 6, the & sigil is used to distinguish between
foo bar
which calls bar and passes the return value to foo, and
foo &bar
which passes bar as a Code object to foo.
-ryan
(sorry, I deleted your message by mistake, I'm attempting to fake up a reply)
Juerd Waalboer
> excessive use of special characters (/\W/).
This seems to be "I don't like regexes". Ignoring for now that Perl 6
regexes will be more verbose and thus easier to read for someone without
much prior exposure to them, what would you suggest as an alternative to
regex matching?
One of the common alternatives is to iterate over a list of characters,
possibly using an index. Would you say that a screen page full of such
code is easier to read and maintain than a single regex on a single
line?
Many languages have regexes, even the cleanest among them. And they're
all as messy as Perl's. They're often more verbose on the outside, which
can result in something like foo.match(/foo/) instead of foo =~ /foo/,
but the /foo/ part is most important here. If you don't recognise what
that is, it doesn't matter if ".match" or "=~" was used.
Many languages have regexes, but Perl was probably the first to apply
them heavily in "normal" programming. And nowadays, they're so
ubiquitous that it's hard to find a language without Perl-ish or "Perl
compatible" regexes. Why do you think this is?
I think it's kind of funny that indeed exactly the most cryptic part of
Perl's syntax is copied to so just about every modern programming
language, while at the same time Perl is constantly criticized for using
"special characters" so much.
No, special characters aren't a problem. They are the fundament of a
very powerful and expressive syntax. Just don't try to understand a
screen full of them all at once -- realise that in another language, the
first three lines would sometimes already fill the same screen, and
adjust your reading speed.
On the other hand, the overall structure of a program is often more
obvious, exactly because so much more fits in one screenful.
In Perl it is often not needed to refactor something to many tiny
subroutines with verbose identifiers, just for legibility.
One thing stays true, though: Perl is very hard to read for someone who
doesn't know Perl well enough. But that's practically true for almost
language, be it Python or Japanese.
--
korajn salutojn,
juerd waalboer: perl hacker <ju...@juerd.nl> <http://juerd.nl/sig>
convolution: ict solutions and consultancy <sa...@convolution.nl>
Larry Wall
: In Perl 6, the & sigil is used to distinguish between
:
: foo bar
:
: which calls bar and passes the return value to foo, and
:
: foo &bar
:
: which passes bar as a Code object to foo.
In other words, the sigil is consistently a noun marker in Perl 6,
even when a sigil is used on a verb. In Perl 6, where sigils
distinguish nouns not only from verbs, but also from adjectives (if
you count types as adjectival). With a glance you can tell which
are the nouns and which are the types here:
multi CatDog sub make_catdog (Cat $cat, Dog $dog) {...}
multi CatDog sub make_catdog (Cat Dog $catdog) {...}
While Gabor is correct that in Perl 5 removing the sigils from verbs
made some verbal collisions happen that otherwise wouldn't have, in
Perl 6 we've mostly fixed that by essentially getting rid of most
reserved words, and making even the builtin functions participate
as normal multis and methods. For that reason, and because verbs
linguistically tend to be disambiguated by the nouns fed to them as
argements, verbs don't need to be conjugated nearly as badly as nouns
need to be declined. A lot of nouns typically don't have arguments
to disambiguate them with, at least until you start subscripting them,
and we don't do multiple dispatch on subscripts.
As for the original complaint, we long ago decided to ignore people who
are prejudiced against languages that mark nouns. Greek wouldn't be
Greek if you couldn't decline your nouns. (In my estimation, it's
the conjugated verbs that make Greek so difficult to learn, really.
On the other hand, once you learn them they're very expressive in
tense and aspect. It's all tradeoffs.)
Larry
Thomas Wittek
> theproblemlinguisticallyspeakingisthatsometimes [snipped]
I can't remember that I said that you shouldn't separate your
expressions (by punctation/whitspaces),
$.but! (*adding$ %*characters _+that^# &$might) @#not_ !#be()
!&necessary_ *#$doesn't! *(make) !@_it$ =_easier
to read and to type (in addition it was a torture to type that).
>> So semicolons don't seem to be the best invention since sliced bread.
>> There should be extra-syntax for the rare cases (multiline) and not for
>> the common ones.
>
> Somehow English seems to get by with periods at the ends of statements, though
> almost no one pronounces them.
Oh, I thought Perl was a programming language. My fault.
Apples and oranges.
Most modern scripting languages don't need the semicolons. I think
there's no plausible reason for them.
> I agree. You need less ignorant colleagues. I'm not sure Perl 6 can fix
> that.
I don't think that it's a point of ignorance.
Especially as they (and enough other people on the web) only seem to be
ignorant regarding Perl. Strange, huh?
> By the way, I'm still waiting to meet your cadre of Dylan hackers.
I never claimed to have some.
Thomas Wittek
> Take a look at
> actual code written in other languages and you'll find many variable
> names that end in things like _ary, _array, _dict, _list, etc.
Actually I've not seen that often. Where I've seen it frequently is in
Visual Basic and Delphi/Pascal.
I hated it too.
But I think that the name of an identifier (noun/verb, single/plural,
the meaning of the word) already gives enough context to understand what
type it is.
And every use of it (assigning and reading) additionally makes it clear.
So _for me_ there is no need for an additional hint for the type.
Doug McNutt
>In other words, the sigil is consistently a noun marker in Perl 6, even when a sigil is used on a verb.
It would seem to me that a preprocessor, written in perl of course, could easily respond to "DIMENSION noun AS double" statements or whatever you like by adding the appropriate sigl every the noun appears without it.
As for "too late" I do have a problem. I started with perl 4 or so as MacPerl with Apple's MPW as a shell. Now, at age 72, I do worry that perl 6 may be too late for me. It's been two years since I got to the point of using the * sigl in perl 5 and I still have a lot to learn about that.
FORTRAN forever.
--
Applescript syntax is like English spelling:
Roughly, though not thoroughly, thought through.
Juerd Waalboer
> $.but! (*adding$ %*characters _+that^# &$might) @#not_ !#be()
> !&necessary_ *#$doesn't! *(make) !@_it$ =_easier
Those characters are meaningless. The many symbols in Perl 6 have very
distinct meanings, which makes them very powerful tools!
> Oh, I thought Perl was a programming language. My fault.
> Apples and oranges.
There is a reason that C programmers don't throw away their source code
after compiling it.
While in some companies, writing software is indeed a unidirectional
process, most companies that wish to survive have to maintain what they
wrote, and then you also have to read it.
Programming languages and spoken languages are both read by human
beings, so they should still be easily parsed by these creatures.
> Most modern scripting languages don't need the semicolons. I think
> there's no plausible reason for them.
They typically have a line continuation character instead of a
semicolon, though. However, like the previous sentence, and this one
too, actually, sometimes there is a line break in between.
Again, written language can be a nice example, because if we had line \
continuation characters in here, it would suddenly look a lot \
different. Did you, while reading this, pause, just before "different"?
Juerd Waalboer
> But I think that the name of an identifier (noun/verb, single/plural,
> the meaning of the word) already gives enough context to understand what
> type it is.
So is "user_id" a variable or a type? How about "substring" or
"document"?
Is "new" a function, or a variable? How about "old"?
Is "is_valid" a function that determines whether something is valid, or
a variable holding the result of this test?
When you have "update(delete_random)", where both update and
delete_random are functions, does this pass the function "delete_random"
to "update", or does it first delete something, and then pass the
resulting value to update? Don't forget that one of the important
decisions in Perl was that we don't always like to use parentheses,
because that clutters code (and you don't want that!!).
Given "HTML Element", is HTML the type and Element the variable of that
type, or is Element the type, and HTML the variable (for example, to
hold the <html> element object)?
Is "pid" a variable you used yourself, for example as the return value
from "fork", or does "pid" give you the pid of your current process? And
if the latter, is that by calling the pid function, or because pid is a
variable?
Doesn't "count input" look wrong to you? It should, because "count" is a
hash! By the way, what would "input" be?
And how on earth would you write "object.foo()", where foo is a variable
holding a reference to a method, not the name of the method, if you had
no sigils?
...
...
...
...
...
| So is "user_id" a variable or a type? How about "substring" or
| "document"?
The Perl Way:
$user_id is a variable, $substring is a variable, $document is a
variable.
user_id is not a variable, substring is not a variable, document is not
a variable.
| Is "new" a function, or a variable? How about "old"?
The Perl Way:
$new is a variable, $old is a variable.
new is not a variable, old is not a variable.
| Is "is_valid" a function that determines whether something is valid, or
| a variable holding the result of this test?
The Perl Way:
$is_valid is a variable.
is_valid is not a variable.
| When you have "update(delete_random)", where both update and
| delete_random are functions, does this pass the function "delete_random"
| to "update", or does it first delete something, and then pass the
| resulting value to update?
The Perl 6 Way:
update(&delete_random) passes the function &delete_random to &update.
update(delete_random) calls the function &delete_random, and passes
whatever it returned to &update.
| Given "HTML Element", is HTML the type and Element the variable of that
| type, or is Element the type, and HTML the variable (for example, to
| hold the <html> element object)?
The Perl 6 Way:
HTML $Element is a variable of the type HTML.
$HTML Element is a syntax error caught early by the compiler. (And
that's really great if your native language makes you think the other
way around than the programming language wants you to.)
| Is "pid" a variable you used yourself, for example as the return value
| from "fork", or does "pid" give you the pid of your current process?
| And if the latter, is that by calling the pid function, or because
| pid is a variable?
The Perl Way:
$pid is a variable that you set yourself.
pid is not a variable.
$*PID is a variable, that represents the pid of your current process.
| Doesn't "count input" look wrong to you? It should, because "count" is a
| hash! By the way, what would "input" be?
The Perl Way:
%count $input (or %count input) looks wrong, error caught even before
compile time, programmer time and energy conserved.
| And how on earth would you write "object.foo()", where foo is a variable
| holding a reference to a method, not the name of the method, if you had
| no sigils?
The Perl Way:
$object.foo() calls the method called "foo".
$object.$foo() calls the method that is in the variable $foo.
Jonathan Lang
important to distinguish between '$', '@', '%', and '&'? I ask
because I've seen a lot of object-based code that has said stuff like
'$container{$key}'; it seems that there's an assumption that $foo can
be used as a list, a hash, or even a routine if the object that it's
tied to has list-, hash-, or routine-like behavior: i.e., it no longer
seems to be "a scalar variable", but rather "a variable". Whereas
'@', '%', and '&' still seem to promise list, hash, and routine
functionality, respectively. In short, there no longer appears to be
a sigil that says "I give my solemn promise that the contents herein
will be scalar."
--
Jonathan "Dataweaver" Lang
Mark J. Reed
> Good examples. Now could you provide some to explain to me why it's
> important to distinguish between '$', '@', '%', and '&'? I ask
> because I've seen a lot of object-based code that has said stuff like
> '$container{$key}';
Well, $container{$key} is how you access elements of %container in
Perl5; in Perl6 that's %container{$key}. But in object-based P5 code,
you'd be much more likely to see $container->{$key}, where $container
contains a reference to a hash. I believe in P6 you could write that
either as $container.{$key}, $container{$key} (where the . is implied
since $container{$key} can't refer to %container anymore), or
%$container{$key}.
If I understand your point, however, it is that the availability of
references, which are scalars, has essentially removed the
scalar/array/hash/sub distinction, since you can store references to
any of those things in a $var. Further, in order to dereference such
references, you need something beyond the sigil anyway, which takes
its place as a type disambiguator.
You aren't the only person who feels this way; there was a proposal
back in the RFC process to remove sigils in favor of "everything is a
scalar, dereference as needed". I was in that camp myself. But Larry
rejected that proposal, defending the utility of sigils, and I have
been swayed by the arguments, which I'm not going to repeat because I
can't say it as well, but I do advise you to go read - it was either
Apoc1 or Apoc2, I think.
Anyway, one of the things I like about the Perl6 design is that it
essentially restores sigils to their pre-Perl5 importance via
automatic referencing and dereferencing according to context. This
effectively removes the "everything's a scalar anyway" argument since
you can toss references around without making everything a $var. (I
dunno how many times I have tried to declare and initialize a hash
with my %hash = { ... }, which initializes the hash to have a single
element whose key is the hash reference provided and whose value is
undef... but in P6 that does the right thing.)
Thomas Wittek
> Thomas Wittek skribis 2007-05-14 22:20 (+0200):
>> But I think that the name of an identifier (noun/verb, single/plural,
>> the meaning of the word) already gives enough context to understand what
>> type it is.
>
You are right, I should have weakened this sentence by "in most cases".
Tricky from you to cut out my next sentence, which was about additional
context that's needed in this cases and that your examples are missing
of course:
> Thomas Wittek also wrote:
>> And every use of it (assigning and reading) additionally makes it
>> clear.
>> So _for me_ there is no need for an additional hint for the type.
Juerd Waalboer wrote:
> And how on earth would you write "object.foo()", where foo is a variable
> holding a reference to a method, not the name of the method, if you had
> no sigils?
That would not happen in my code.
I consider having the same name for different things bad.
I even wouldn't do that _with_ sigils.
> The Perl Way:
> $object.foo() calls the method called "foo".
> $object.$foo() calls the method that is in the variable $foo.
My way:
someref = &somemethod
object.someref()
Of course you could argue that you don't know in advance, if "object"
has a method with that name, so you cannot manually avoid the conflict.
But it should be no problem to put out a warning/error at runtime (or
maybe even at compile time) when a variable name clashes with a method name.
Thomas Wittek
> Thomas Wittek skribis 2007-05-14 0:42 (+0200):
>> excessive use of special characters (/\W/).
>
> This seems to be "I don't like regexes". Ignoring for now that Perl 6
> regexes will be more verbose and thus easier to read for someone without
> much prior exposure to them, what would you suggest as an alternative to
> regex matching?
Not ignoring that will nullify your argument.
Regexps/rules are great, and I never said anything differing. If the
syntax gets more readable without any cost (in which I belive) its even
better.
Now do s/Regexps\/rules are/Perl is/ on the last sentence.
> On the other hand, the overall structure of a program is often more
> obvious, exactly because so much more fits in one screenful.
My suggestions won't have an impact on the expressiveness of Perl.
So in many cases you might have even less characters on your screen.
Of course some special character sequences would be replaced by word
character sequences, but that won't fill your screen by a magnitude.
Austin Hastings
> chromatic wrote:
>
>> theproblemlinguisticallyspeakingisthatsometimes [snipped]
>>
>
> I can't remember that I said that you shouldn't separate your
> expressions (by punctation/whitspaces),
> $.but! (*adding$ %*characters _+that^# &$might) @#not_ !#be()
> !&necessary_ *#$doesn't! *(make) !@_it$ =_easier
> to read and to type (in addition it was a torture to type that).
>
Forgive chromatic. Part of joining @Larry is undergoing a painful
initiation process, which tends to inspire zealotry.
The point, though, is that there are three ways of handling the whole
"part of speech" issue. One is with a dictionary (reserved words): in
this method, every word is assigned a part of speech, usually with a
"default." Any use of the word "FOR" must be a loop, any use of "INT"
must be a typedef, etc.
Another is with context (and predeclaration). In this method, the
surrounding context can be used to infer the part of speech of a word,
with some sort of confirmation for 'new' words (user-defined variables,
functions, etc.). Most present-day compiled languages use this one,
although they frequently rely on the "reserved words" approach, too, for
some words.
Finally, the approach Larry has chosen is to explicitly mark the part of
speech. Perl up to version 5 used an approach that attempted to
correlate the marker with the part of speech associated with the
surrounding context: foo(@array) vs. foo($array[0])
This approach was criticized for providing relatively little value over
the context+lookup approach. If the sigil has to correspond to the
context, then only in rare cases (ambiguous context) is the sigil adding
much value.
The new approach (@array[0]) ties the sigil to the declaration, serving
to distinguish name collisions and of course to autovivify variables
correctly.
Ultimately, it comes down to value added, and culture/custom. "Perl has
always used sigils, so perl should continue to use sigils." That's a
legitimate stand, in the absence of compelling arguments to the
contrary. It "let's perl be perl."
As far as value goes, let's call the C/C++ approach the "nul" approach,
since by default there is no sigil in front of words. (And I'm
considering * and & to be sigils, rather than operators.)
The nul approach reduces typing. It relies on context to identify the
part of speech, occasionally forces some look-ahead (a name followed by
'(' is an invocation instead of a reference) and can't handle multiply
typed (@foo vs. &foo vs. $foo vs. %foo) names.
The perl approach increases typing, by something less than 1 character
per identifier. (This is a real cost, that Larry continues to elect to
bear.) The p5 version imposed some disambiguation burden on the parser,
since $foo[0] involved @foo, not $foo. Perl *can* handle *some* multiply
typed names. There is a difference between $foo and @foo, but not
between "my Cat $foo" and "my Dog $foo".
In addition, however, there is the whole *foo thing. Adding the sigil
has encouraged people to think in weird ways, 'tied' variables and
typeglobs not least among them. I don't know if a 'perl' that used the
nul approach would ever have had those features. (Sapir-Whorf lives!)
The perl approach, then, opts to pay a significant penalty (0.9+
characters per variable) to allow access to the cool extra features that
few other languages use, and none so compactly.
A similar trade-off exists with the statement terminating semicolon. In
this case, it involves the number of statements per line:
A language that terminates statements can ignore whitespace, allowing
multiple statements per line and statements that span multiple lines.
A language that associates line termination with statement termination
must pay a separate cost (continuation marker) for a statement to span
multiple lines. It will not, in general, support multiple statements per
line. (Though it could make the terminator "optional" and then inject
terminators between colinear statements.)
The vast majority of languages have opted to terminate statements. Perl
is among them. Probably the best argument is that encountering a
semicolon (or full stop, in COBOL) is a positive indicator rather than a
negative one. "I see a semicolon. I know the statement is over." as
opposed to "I don't see a continuation marker, so it's likely that the
statement is over, although it could be tabbed way off to the right or
something."
Also, there's the increasing size of words to consider. While $a = $b +
$c is a great example of why line termination is not needed, the trend
is for variable and function names, not to mention object and method
dereferences, to grow longer.
From
http://www.oreillynet.com/pub/a/javascript/2003/03/18/movabletype.html I
get:
|MT::Template::Context->add_tag(HelloWorld => sub { return 'Hello World.'; } );|
The MT::...add_tag method name alone is 30 characters. Jam a few long
identifiers together and you're writing a lot of multi-line statements.
If the termination marker were optional, then the punctuation would
still have to be reserved--it is unlikely there is another use for
semicolon that is obviously exclusive from statement termination that
needs to be filled.
And if the termination marker were not optional, but prohibited, then
perl wouldn't have one-liners. That's DEFINITELY "unperlish," so we
won't go there.
So line termination doesn't gain a punctuation character, and causes the
ends of lines to be uncertain. It does reduce typing, for the small
crowd of people that wouldn't just use them anyway because they use them
in every other language.
I think the lack of value here outweights the "savings" of one character
per line.
>
>>> So semicolons don't seem to be the best invention since sliced bread.
>>> There should be extra-syntax for the rare cases (multiline) and not for
>>> the common ones.
>>>
>> Somehow English seems to get by with periods at the ends of statements, though
>> almost no one pronounces them.
>>
>
> Oh, I thought Perl was a programming language. My fault.
> Apples and oranges.
> Most modern scripting languages don't need the semicolons. I think
> there's no plausible reason for them.
>
>
Actually, perl is probably the most "linguistic" of programming
languages. A lot of $Larry's concerns with perl syntax, and perl
language issues, has historically been linguistic concern. The notion of
"end weight," for example, was an important part of the restructuring of
regexes in p6. (See http://en.wikipedia.org/wiki/Larry_Wall)
I'm going to forgive you the "no plausible reason for them" comment,
since I listed some above. (And since chromatic got you riled up.) But
please keep in mind that there are reasons for them, and some of those
reasons are reasons of "custom" (i.e., "we always did it like this" or
"everybody does it") and custom really is a good reason, although proven
value can trump custom. Also, of course, remember that Larry's a pretty
smart guy, particularly in the linguistics field. There are more people
working in perl than work in Esperanto.
>> I agree. You need less ignorant colleagues. I'm not sure Perl 6 can fix
>> that.
>>
>
> I don't think that it's a point of ignorance.
> Especially as they (and enough other people on the web) only seem to be
> ignorant regarding Perl. Strange, huh?
>
>
Regarding perl6, yes. Regarding all of perl, not so much. I think this
goes back to "perl 6 is late," which is really just another way of
saying "perl 6 has taken a long time." Since perl5 is a functioning,
popular language, it's not like there's an "incredibly popular scripting
language" gap...
>> By the way, I'm still waiting to meet your cadre of Dylan hackers.
>>
This little snip is especially interesting since working with early
versions of perl 6 required mastering Haskell, a language that doubled
in popularity when the 2 computer scientists using it were joined by
Luke Palmer and Autrijus Tang.
Keep yer stick on the ice.
=Austin
Juerd Waalboer
> Good examples. Now could you provide some to explain to me why it's
> important to distinguish between '$', '@', '%', and '&'?
It's useful code self documentation, but not very important, in my
opinion.
If you have sigils, it makes sense to have different sigils for
different things, because that allows very nice shorthands (remember how
this thread was originally more or less about avoiding clutter?) like:
sub foo (@bar, $baz) { ... }
And of course, different behaviour in list context:
my @quux = (@foo, @bar); # These arrays "foo" and "bar" flatten
my @quux = ($foo, $bar); # These arrays "foo" and "bar" do not
That's a subtle yet very useful distinction.
But this is "just" very handy, not important.
Chromatic
> But it should be no problem to put out a warning/error at runtime (or
> maybe even at compile time) when a variable name clashes with a method
> name.
Do you always know all of the method names in your entire memory space at
compile time?
-- c
Juerd Waalboer
> > The Perl Way:
> > $object.foo() calls the method called "foo".
> > $object.$foo() calls the method that is in the variable $foo.
> My way:
> someref = &somemethod
> object.someref()
> Of course you could argue that you don't know in advance, if "object"
> has a method with that name, so you cannot manually avoid the conflict.
Indeed. Now you have to know your object very well, and avoid all of its
method names for variable names. For example, an HTTP::Request object
has a .headers method. If Your Way were in effect, I could no longer
safely use the name "headers" for my own variables, and then still call
the "headers" method on the object.
Perl allows both avoiding clashes and not-avoiding clashes. Your way
only strictly requires the former programming style. And since my
preferred style is different, I'm glad you're not designing Perl 6.
Thomas Wittek
> A similar trade-off exists with the statement terminating semicolon. In
> this case, it involves the number of statements per line:
>
> A language that terminates statements can ignore whitespace, allowing
> multiple statements per line and statements that span multiple lines.
Still possible with optional semicolons (as you say later):
a = 1
b = \
2
c = 3; d = 4
> The vast majority of languages have opted to terminate statements.
Most of the younger scripting languages didn't.
> Probably the best argument is that encountering a
> semicolon (or full stop, in COBOL) is a positive indicator rather than a
> negative one. "I see a semicolon. I know the statement is over." as
> opposed to "I don't see a continuation marker, so it's likely that the
> statement is over, although it could be tabbed way off to the right or
> something."
Your semicolon could also be tabbed way off, so you can't be sure there
either.
"I see no semicolon, so it's likely that the statement continues on the
next line".
> So line termination doesn't gain a punctuation character
No problem I think.
> and causes the ends of lines to be uncertain.
It's exactly as certain as with semicolon termination. See above.
> It does reduce typing, for the small crowd of people that wouldn't
> just use them anyway because they use them in every other language.
> I think the lack of value here outweights the "savings" of one character
> per line.
But even if the advantage of line termination is low (some characters
saved, some people might say it looks cleaner), I cannot see any
advantage of semicolon termination.
Juerd Waalboer
> > On the other hand, the overall structure of a program is often more
> > obvious, exactly because so much more fits in one screenful.
> My suggestions won't have an impact on the expressiveness of Perl.
Not so.
Consider /@foo/, which is an alternation of all the elements of @foo.
That's not "just" interpolation, it's something very smart, and even
without seeing the context that this regex is in, I know how to read
this. I don't have to scroll back up to find out that "foo" was once
assigned an array.
> So in many cases you might have even less characters on your screen.
Less characters isn't always better. Often it's worse, sometimes it's
better. It appears to me a hell of a job to find out when it's what, and
I think Larry figured it out quite well.
> Of course some special character sequences would be replaced by word
> character sequences, but that won't fill your screen by a magnitude.
Of course. Every symbol can be substituted for a word comma but that
doesn apostrophe t automatically make code easier to read period I think
a language needs a good balance between symbols and letters comma and
for a programming language comma I think alternating between the two is
close to a perfect balance comma whereas in human languages once, every
$few (words) is.probably<better>; "period"
Thomas Wittek
No, and as I wrote to Juerd, I now think that it's also not a good idea
at runtime.
Jonathan Lang
> Jonathan Lang wrote:
> > Good examples. Now could you provide some to explain to me why it's
> > important to distinguish between '$', '@', '%', and '&'? I ask
> > because I've seen a lot of object-based code that has said stuff like
> > '$container{$key}';
>
> Well, $container{$key} is how you access elements of %container in
> Perl5; in Perl6 that's %container{$key}. But in object-based P5 code,
> you'd be much more likely to see $container->{$key}, where $container
> contains a reference to a hash.
True; but not at all what I was referring to.
> I believe in P6 you could write that
> either as $container.{$key}, $container{$key} (where the . is implied
> since $container{$key} can't refer to %container anymore), or
> %$container{$key}.
_This_ is closer to what I'm referring to. As I understand it, Hash
is a role that provides (among other things) postcircumfix:<{ }>. So
any object that does Hash should be able to call the above method.
And unless I've missed something, there's nothing in perl 6 that
insists that an object that does Hash must be assigned to a variable
that uses the '%' sigil; the '$' sigil seems to work equally well.
i.e., I've seen code to the effect of:
class Foo does Hash { ... }
my $obj is Foo;
$obj<key> = 5;
say $obj<key>;
In short, it appears that there's nothing keeping you from assigning
hash-like or list-like objects to scalar variables.
And this is without bringing references into the picture.
> You aren't the only person who feels this way; there was a proposal
> back in the RFC process to remove sigils in favor of "everything is a
> scalar, dereference as needed". I was in that camp myself. But Larry
> rejected that proposal, defending the utility of sigils, and I have
> been swayed by the arguments, which I'm not going to repeat because I
> can't say it as well, but I do advise you to go read - it was either
> Apoc1 or Apoc2, I think.
I have never been in that camp. In fact, I tend to see the points I
raise above as a bug, not a feature.
Perhaps the relationship between sigils and roles will be addressed in
the as-yet unwritten S14 (or whichever spec is supposed to address
tied variables)?
--
Jonathan "Dataweaver" Lang
Thomas Wittek
> Thomas Wittek skribis 2007-05-15 0:48 (+0200):
>>> The Perl Way:
>>> $object.foo() calls the method called "foo".
>>> $object.$foo() calls the method that is in the variable $foo.
>> My way:
>> someref = &somemethod
>> object.someref()
>> Of course you could argue that you don't know in advance, if "object"
>> has a method with that name, so you cannot manually avoid the conflict.
>
> Indeed. Now you have to know your object very well, and avoid all of its
> method names for variable names. For example, an HTTP::Request object
> has a .headers method. If Your Way were in effect, I could no longer
> safely use the name "headers" for my own variables, and then still call
> the "headers" method on the object.
You are right, it would not be practical to prohibit variable names to
be the same like any other object method names.
But still I can't imagine a useful example where I want so call a method
of object A on object B, which doesn't have this method.
Would it be a good idea to call methods on objects, that never thought
of this methods?
If it wasn't allowed to do so (because it may be not a good idea at all
-- i don't know), we wouldn't have that problem:
Storing a reference to a method of object A, that will only be called on
object A could be done like this:
my ref = A.method
ref()
> Perl allows both avoiding clashes and not-avoiding clashes. Your way
> only strictly requires the former programming style. And since my
> preferred style is different, I'm glad you're not designing Perl 6.
I'm also glad not to do that as I don't think that I'd have the
knowledge to do that.
I just offer my thoughts.
Juerd Waalboer
> Would it be a good idea to call methods on objects, that never thought
> of this methods?
Absolutely! Roles can be used for that too.
Darren Duncan
to differentiate variables from routines, that is, a $ prefix versus
either & or no prefix. However, I generally do *not* like the @ and
% prefixes. They seem somewhat contrived so to cover very specific
variable types while other very similar types don't have them, eg
built-in arrays versus some array-like other container type.
And so in my own coding style I use $ for all arrays and hashes too,
so all my variables are $. This is done consistently in both Perl 5
and Perl 6. The only place a @ or % appears is when I have to say
@{} or %{}, and even then it is mainly just Perl 5 that requires
this, such as in foreach or map. Perl 6 is an improvement over Perl
5 in that it is easier to use $ for arrays and hashes too without
making code more verbose as a result.
I would be happy if Perl 6 dropped the @ and % for arrays and hashes,
using just $ instead; however, I won't necessarily request this as
the semantics of @ and % can be useful (assignment copy by value
rather than by reference), and I can choose to not use them if I
don't want to (TIMTOADY and all that).
On the other hand, unless this steps on something, I could suggest
dropping the @ and % anyway, so we have $array and $hash, and then we
could instead use the @ and % sigils as a prefix to indicate in that
case that we want them to copy by value. For example:
my $foo = [23, 434, 6];
my $bar;
$bar = $foo; # copy by reference
@$bar = @$foo; # copy by value
Actually, I think that would be a vast improvement, as we could then
use the @ prefix with any collection type as short-hand to say that =
is copy by value.
I also don't think the language would feel any less Perlish with this change.
-- Darren Duncan
Jonathan Scott Duff
>
> Moritz Lenz schrieb:
> >> What makes Perl hard to read is the excessive use of special characters
> >> (/\W/).
> >
> > I disagree: The make it look ugly, but not hard to read.
>
> Even if it's "only" ugly: To what advantage? I don't think ugliness is a
> good characteristic of a programming language.
Some people consider mathematics ugly too, but expressivity for
mathematicians is valued more over general readability. So too in perl.
(This is related to "learn once, use often")
>> Additionally I'm not a friend of sigils:
> >
> > Then you shouldn't program in perl. Really.
>
> Reason? I still haven't seen a good justification for sigils.
Whether you like it or not, sigils are a part of Perl's personality that
aren't going away any time soon. If you don't like them, then you shouldn't
use perl. All those people claiming that Perl 6 isn't Perl would be on the
money if Perl 6 didn't have sigils.
To allow arrays and scalars and subs to have the same name (besides the
> sigil) although they have different content? No good idea I think.
> I also can't remember that I ever named a variable like a "reserved
> word" or operator. And even if I could, I'd consider it to be bad style.
I think of it more like hungarian notation. The sigils enable a default set
of expectations. "Oh, I see an @, so this thing must be an array". Perl 6
has changed the meaning behind the notation ever so slightly, but the
utility is still there.
-Scott
--
Jonathan Scott Duff
perl...@gmail.com
Darren Duncan
>On the other hand, unless this steps on something, I could suggest
>dropping the @ and % anyway, so we have $array and $hash, and then
>we could instead use the @ and % sigils as a prefix to indicate in
>that case that we want them to copy by value. For example:
>
> my $foo = [23, 434, 6];
> my $bar;
> $bar = $foo; # copy by reference
> @$bar = @$foo; # copy by value
>
>Actually, I think that would be a vast improvement, as we could then
>use the @ prefix with any collection type as short-hand to say that
>= is copy by value.
As a follow-up or clarification of what I just said, here is a proposal ...
Variables of all types have $ sigils.
The semantics of $foo = $bar are unchanged; usually $foo and $bar
point to the same container after the assignment, afaik.
Prefixing a @ or % before a variable name indicates a syntactic
short-hand for something concerning the variable.
On declaration, saying @$foo means the same as "Array $foo", and
saying %$foo means the same as "Hash $foo", or some such. This works
for my|our|has etc as well as parameter declarations. This is
instead of declaring @foo or %foo.
On use in an expression, @$foo = @$bar indicates we want a copy by
value or clone or shallow copy or whatever, and $foo and $bar point
to different containers after the assignment; the semantics are like
the current @foo = @bar.
Similarly, use eg @@$foo rather than @@foo as appropriate.
With these changes, I see it making Perl more consistent in
appropriate ways, and easier to use, and huffmanizing isn't worse.
Also, it means we can free up the @ and % rare ASCII symbols for
other purposes in some situations.
I could also argue that the conception of @ meaning plural vs $
singular isn't really an absolute, since any value can be treated as
either being a collection or being atomic under different
circumstances.
-- Darren Duncan
Tibor Foeldes
> As Ruby and Python are getting more and more attraction [1][2] I think
> they do something right, that Perl doesn't.
> What I think where both (especially Python) do better is in readable
> code.
>
> What makes Perl hard to read is the excessive use of special characters
> (/\W/).
>
It is in Ruby the same. In Python re.search('\W',foo). Is it
really nicer ?
> In my opinion, reducing the use of those characters would make Perl a
> lot easier to read and also easier to write.
> Global variables with cryptic names, that no beginner can make any sense
> of by reading it. And after not working with "$<" for some months I
> can't remember it either, although I've got quite some Perl experience.
>
>
In Perl6: $*UID (see S02.pod)
> Additionally I'm not a friend of sigils: Typing them is relatively
> painful, for reading there is no advantage if you use an editor with
> decent syntax highlighting and the code looks more cryptic. The answer
> in Perl6 are twigils, great... One step backwards in my optinion.
> Most programming languages
> /C(++|#)?|Java(Script)?|Python|Ruby|Groovy/... don't need them. The only
> obvious advantage of using sigils is variable interpolation in strings.
> But that could easily be done only in strings without the need to put a
> $ in front of each and every variable name in the rest of the code.
>
>
Perl is a language with sigils. We must see it more penetrating ! The
advantages of sigils in Perl are overall, by item access in structures,
by the flexibility of subroutine calls, interpolation , global
variables, ....
Perl wants separate variables from other language structures . Perl
without sigils is not Perl more. Perl6 in this regards is really to
late for you :-)
> I would also like semicolons to be optional. There are far more cases of
> single line statements than multiline statements. So you would save
> quite some characters, when the semicolon would be optional and you
> could concatenate multiline statements with e.g. a backslash.
>
> Some say that there are too much operators in Perl(6). I partially
> agree. I don't like the implicit type casting forced by the operators
> (== int / eq string). That's harder to learn and remember. Harder to
> read also.
Operators are only another format ( nice ) of functions.
> I really like the Python way of doing it: Set the variables type on the
> assignment and remember it. The (fewer) operators now work according to
> the type of the operands. No implicit (and error prone) type casting.
> That way seems to be the best compromise of easiness and type safety.
> I could continue on that, but I've already written too much...
>
"use warnings" is helping you !
And you can always make explicit type conversion. That does mean
explicit :-) . But you must type something more.
The only builtin implicit type casting in Perl is this numeric / string
conversion and it is fairly obvious and absolutely not error-prone.
> [1] http://radar.oreilly.com/archives/2007/05/state_of_the_co_6.html
> [2] http://www.google.com/trends?q=perl%2C+python+-snake%2C+ruby
>
>
These reports are fairly special. These are not about popularity of a
programming language , but
how many books O'Reilly sold, and how many were googled. What about is
not clear. Maybe waiting for Perl6 ?
In place of contributing? Searching for redemption ?
> People not only want code that _is_ sexy, but they also want it to
> _look_ sexy.
>
Sex is oftentimes perversion ;-) Well, natural selection. Survives the
fittest idea , not necessarily the sexiest look.
Tibor
Larry Wall
Larry
Garrett Cooper
> Moritz Lenz schrieb:
>>> What makes Perl hard to read is the excessive use of special characters
>>> (/\W/).
>>
>
> Even if it's "only" ugly: To what advantage? I don't think ugliness is a
> good characteristic of a programming language.
>
>>> of by reading it. And after not working with "$<" for some months I
>>> can't remember it either, although I've got quite some Perl experience.
>>
>
> I hope so. I could only find the counterparts for __PACKAGE__ etc. in
> S02. I didn't find the one for e.g. $<.
>
>>> Additionally I'm not a friend of sigils:
>>
>
> Reason? I still haven't seen a good justification for sigils.
> sigil) although they have different content? No good idea I think.
> I also can't remember that I ever named a variable like a "reserved
> word" or operator. And even if I could, I'd consider it to be bad style.
No one mentioned that if it wasn't for sigils, many strings would be
increased, length-wise, to do operator concatentation. If it wasn't for
that then simple string insertions couldn't be used.
Plus sigils are a defacto form of representing variables in other
languages, like Unix scripting and PHP. I'd rather read a data item
[scalar, { associative, 1-D } array, list, class object ] and have a
good idea of what the target data type is. References is the only data
type ones that introduces some sort of mystery to this mix, IMO.
>>> I would also like semicolons to be optional.
>>
>> Most people don't ;-).
>
> Oh, really? Source? :)
> I think they were invented to allow easier parsing and not easier coding.
> E.g. in JavaScript, Python, Ruby and Groovy they are optional or even
> don't exist. As I said, there are much more cases where you wouldn't
> need them but have to write them than vice versa.
> Optional semicolons save keystrokes, eye pain and stupid syntactic
> errors. And if you still like them, you could just use them, which is
> the definition of "optional".
Almost all mainstream languages do it though, and it serves as nice
visual breaks in source. I honestly hate lack of semi-colons, with the
exception of shell scripts, all of which I produce that are less than
150 lines long.
Then again I don't do more than 2 sets of statements in a given line for
shell scripts either, and I don't so the same with Perl.
<rant>
The only thing I hate about Perl with required formatting is the silly
braces. If it's one line and separated by visible whitespace, why is the
only option available to me the
statement_1 if(statement_2);
or
statement_1 unless(statement_2);
syntax? Seems less readable than:
if(statement_2)
statement_1
or
unless(statement_2)
statement_1
The only legitimacy for the first set of formats would be if in fact you
were reading off the logic statement in a left-to-right language. But
then again many languages don't follow that convention (Japanese,
Korean, etc etc for instance).
The same opinion goes for all loops, except the
do { statement } ( { while, until } );
variety.
</rant>
>>> I really like the Python way of doing it: Set the variables type on the
>>> assignment and remember it. The (fewer) operators now work according to
>>> the type of the operands. No implicit (and error prone) type casting.
>>> That way seems to be the best compromise of easiness and type safety.
>>
>> Well, if you like the python way, feel free to code in python.
>
> Oh, if I didn't like Perl, why should I care about posting my ideas here?
> Perl has stolen the largest part of the language from other languages.
> Why not do so again by adopting good ideas.
>
>> Don't get me wrong, there's nothing bad in writing some critics, but
>> yours is impossible to realize in Perl 6
>
> Admittedly I'm much too late and I didn't expect applause for my critics
> -- but at least I hoped to get a discussion based on arguments.
>
> > and therefore are it's hard to call it constructive.
>
> Unfortunately I already thought this. Even if everyone agreed that
> sigils (or forced semicolons, or tons of operators, ...) are more bad
> than good (and this seems like persuading the pope to allow homosexual
> muslims to marry with priests) the design process is probably too far to
> introduce such dramatic changes.
> Sadly.
Yes, probably about as likely as Neo-Nazi's getting married to Haccidic
Jewish people with Satanic priests presiding.
-Garrett
Larry Wall
: No one mentioned that if it wasn't for sigils, many strings would be
: that then simple string insertions couldn't be used.
Well, except you can interpolate in Perl 6 with bare closures, so
say "answer = {foo}"
wouldn't be so bad.
: The only thing I hate about Perl with required formatting is the silly
: braces. If it's one line and separated by visible whitespace, why is the
: only option available to me the
:
: statement_1 if(statement_2);
:
: or
:
: statement_1 unless(statement_2);
:
: syntax? Seems less readable than:
:
: if(statement_2)
: statement_1
:
: or
:
: unless(statement_2)
: statement_1
That has been a not-infrequent complaint about Perl from people coming
from a C-ish background. However, what we discovered with the Perl 6
design was that it was not, in fact, the braces that were silly, but
the parentheses. The braces consistently represent a closure in Perl 6,
even in control constructs, which are not special-cased as in C and Perl 5.
But by taking that approach we can get rid of the parens that are doing
only syntactic work without carrying any semantic weight. So Perl 6 ends
up with the one-liner:
if statement_2 { statement_1 }
and that's no more characters than your parentesized version.
Now you might think that the curlies are still useless there, but the
fact that it's a closure means you can capture the value of the control
condition if you like. This would be rare with an if, but with other
control flow structures it's quite common. In particular this very
common construct:
for 1..100 -> $i { say $i }
Since -> is just a built-in way of writing an anonymous sub with
arguments, there's no need to invent special syntax for loop variables!
And when you say
for 1..100 { say $_ }
you're still logically calling an anonymous sub with a single parameter
called $_. I freely admit that the use of braces in C and Perl 5 is
silly, but the braces in Perl 6 are about as far from silly as you
can get.
: The only legitimacy for the first set of formats would be if in fact you
: were reading off the logic statement in a left-to-right language. But
: then again many languages don't follow that convention (Japanese,
: Korean, etc etc for instance).
Oddly, the statement modifier is borrowed directly from English.
: The same opinion goes for all loops, except the
:
: do { statement } ( { while, until } );
:
: variety.
That particular construct comprises several additional cans of worms. :)
Larry
Herbert Breunung
> Language design is hard. Let's go shopping! :-)
>
> Larry
>
>
oh wait the ponie is dead,
i hope i didnt say something wrong :-)
Darren Duncan
Larry today (before the thread on mutable arguments), and I learned
that one of my main concerns, of inconsistency between different
collection types, is not valid.
http://colabti.de/irclogger/irclogger_log/perl6?date=2007-05-17,Thu&sel=126#l221
1. Not just Array, but also Seq can typically bind to both @ and $.
2. Not just Hash, but also [Mapping,Set,Bag,Pair,etc] can bind to
both % and $.
So its not just Array and Hash with the extra sigils, while
everything else has only the $.
I now recommended that the Synopsis be updated to explicitly clarify
such as these details, to make things less ambiguous for future
readers, and they don't make the same mis-assumptions that I did
about the limited scope of @ and % use.
That is, the Synopsis should explicitly state which are all the
built-in types that could typically bind to each of the sigils (and
everything can bind to $).
Larry thought that perhaps S02 would be the place for it.
In conclusion, I retract my previous suggestion of just using $ where
we used to use @ and %.
-- Darren Duncan
Paul Hodges
It's a valid aside to note that, while people know what singular and
plural are, few people use or even refer much to the Greek use of a
special intermediary (the dual) when there were exectly two of
something...but the basic mindest of dichotomy is a fundament of the
language. (c.f. the men/de construct so basic to the language).
Perl is like that. There are a lot of little corner cases that are
distinctly Perl, things unlikely to be seen elsewhere, and sometimes
hardly ever even used in Perl.... but the mindset that is Perl is a
beautiful thing, and that's still there.
Besides, if you don't get the aesthetics of the Schwartzian Transform,
then you should probably be using python or java anyway, hm?
Let's let Perl be Perl. It's a new Perl, but it's still a pearl. =o)
*Paul
--- Larry Wall <la...@wall.org> wrote:
> On Mon, May 14, 2007 at 02:21:47PM -0400, Ryan Richter wrote:
> : In Perl 6, the & sigil is used to distinguish between
> :
> : foo bar
> :
> : which calls bar and passes the return value to foo, and
> :
> : foo &bar
> :
> : which passes bar as a Code object to foo.
>
> In other words, the sigil is consistently a noun marker in Perl 6,
> even when a sigil is used on a verb. In Perl 6, where sigils
> distinguish nouns not only from verbs, but also from adjectives (if
> you count types as adjectival). With a glance you can tell which
> are the nouns and which are the types here:
>
> multi CatDog sub make_catdog (Cat $cat, Dog $dog) {...}
> multi CatDog sub make_catdog (Cat Dog $catdog) {...}
>
> While Gabor is correct that in Perl 5 removing the sigils from verbs
> made some verbal collisions happen that otherwise wouldn't have, in
> Perl 6 we've mostly fixed that by essentially getting rid of most
> reserved words, and making even the builtin functions participate
> as normal multis and methods. For that reason, and because verbs
> linguistically tend to be disambiguated by the nouns fed to them as
> argements, verbs don't need to be conjugated nearly as badly as nouns
> need to be declined. A lot of nouns typically don't have arguments
> to disambiguate them with, at least until you start subscripting
> them,
> and we don't do multiple dispatch on subscripts.
>
> As for the original complaint, we long ago decided to ignore people
> who
> are prejudiced against languages that mark nouns. Greek wouldn't be
> Greek if you couldn't decline your nouns. (In my estimation, it's
> the conjugated verbs that make Greek so difficult to learn, really.
> On the other hand, once you learn them they're very expressive in
> tense and aspect. It's all tradeoffs.)
>
> Larry
>
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