»ö« Welcome to Perl 6! | perl6.org/ | evalbot usage: 'p6: say 3;' or rakudo:, or /msg camelia p6: ... | irclog: irc.perl6.org or colabti.org/irclogger/irclogger_logs/perl6 | UTF-8 is our friend!
Set by moritz on 22 December 2015.
teatime that doesn't seem to be the case 00:00
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geekosaur (\X being a codepoint followed by any number, including zero, of modifiers) 00:00
teatime m: say '"̃"' ~~ rx:Perl5/^./
camelia rakudo-moar ec6c3b: OUTPUT«「"̃」␤»
geekosaur er, of combining codepoints
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geekosaur if you hadn't noticed, rx:perl5 is not complete (and I would say in this example not correct) 00:00
probably as NYI as the modifiers :bytes etc 00:01
I'm testing them locally in perl5
remember that in perl 6, the string '"̃"' itself has only one character in it: a synthetic codepoint 00:03
..,wow, hexchat mangled that
teatime well that string has two
but yes I understand it doesn't have three 00:04
geekosaur yeh, I copy-pasted and hexchat doubled the "
but that means that rx:p5 would have to undo that to work just like perl 5, and it doesnt know that it needs to do that
so it's matching more than it should with ^.
teatime yes
I understand it's nyi, that's fine 00:05
geekosaur if youi do it in actual perl 5, it matches only one codepoint
teatime I was just testing and hoping.
interestingly, putting a ZWNJ after the opening " does not break up the grapheme, either to perl or on my terminal
would have thought it would
geekosaur I think that's a known glitch 00:06
actually ZWNJ is misrecognized/misimplemented all over the place
teatime I figured P6 would implement that w/ maybe 50% probability, but really shocked it doesn't work in my terminal
geekosaur I think jnthn ran into that while developing the current grapheme implementation
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zwu I understand it is too early to test the performance of perl6, due to my interesting, I tested perl6 performance for the same task at github.com/famzah/langs-performance, sorry I don't have the perl 6 code right on my computer, but from my test on perl 6 April release, it is about 18x slower than python2. 01:01
the benchmark of other language performance are there.
The code for perl 6 is very similar to other code for the implementation, I could post it tomorrow too. 01:02
gfldex it is for sure not to early to test the performance of Perl 6. It is however to early to expect the same performance then a language that was released in 1991. 01:03
timotimo please ping me with the code when you have it :)
zwu here is the benchmark of other language: blog.famzah.net/2016/02/09/cpp-vs-...mark-2016/
timotimo i wonder if you used "int" or "Int" in the perl6 code 01:04
zwu I used Int and @array using push
timotimo wow, your get_primes7 has a prototype definition 01:05
in the perl5 code, i mean
zwu so that could be the performance problem.
timotimo not necessarily :)
zwu btw: it is not my code on the git github.com/famzah/langs-performance.
timotimo as long as the numbers don't exceed 32bit, we at least don't allocate a full mp_int
but we're currently pretty dumb when it comes to creating far too many intermediate boxed results, and we have a few things that immediately prevent inlining in some cases, which really hurts performance 01:06
but all in all, 2016 is the year where many performance improvements will be made
zwu I believe there will be many performance improvements !!! 01:07
timotimo just yesterday lizmat gave Int a little performance optimization pass with results like div and / for Int, Int being about 50% faster
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timotimo i'm interested in running the code you came up with under --profile 01:10
zwu ok, I put my primes.p6 code there gist.github.com/anonymous/f31c6b7e...9a1085894, sorry for I didn't create a github repo. 01:14
timotimo not important, a gist is good enough 01:15
there seem to be some tab characters mixed in there :) 01:16
how long does it take on your machine, approximately?
zwu 531 seconds 01:17
run at a virtual machine. 01:18
for python2 it is about 31 seconds.
timotimo thanks
i'll probably have my sleep before actually working on this, though
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timotimo already a c-level profile reveals 8.2% spent in total just marking an array of objects 01:28
17% of overhead related to invoking frames, which means the optimization we're going to get this or next week will give a decent benefit here even before the code itself has been optimized 01:29
well, i'd even go as high as 25%
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gfldex it's filling up 1.3GB of RAM 01:38
timotimo it's going gc-crazy, too 01:39
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timotimo 69660380 Int objects, 59977737 Scalar objects 01:39
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timotimo and an astronomical amount of BOOTHash, which i'm not 100% sure about their correctness 01:40
gfldex does `Int(sqrt($n))` acutally create an Int obj, even if the result ends in `int`? 01:41
timotimo "ends in"?
gfldex like in `my int $mroot = Int(sqrt($n))`;
timotimo just by sprinkling a few "int" around, i get from 272504.78ms to 159403.75ms
(but this is only 5 runs, not 10)
it will create an Int, yes 01:42
gfldex m: my @primes = (1..10000000).grep(*.is-prime); say @primes.elems;
timotimo i see a tremendous amount of IntLexRef being generated, which tells me my nativifying is doing the "stop all inlining now!" thing 01:43
camelia rakudo-moar ec6c3b: OUTPUT«(timeout)»
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timotimo gfldex: wanna try out if you can do better than the loop that puts odd numbers into the @s array? 01:46
like with a "..." for example
or by using the return value of a loop 01:47
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gfldex i would like to keep the algorithm the same for a start to see how far I get that way. I do know the max size of the result array, so a native shaped is worth a try. 01:48
timotimo no, definitely not native shaped; they are currently the opposite of optimized 01:49
they will give you terrible performance
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timotimo it seems like 3, 5, 7 ... * > $n is slower than the loop with push in it :) 01:50
gfldex if it gets cache friendly it may still lead to a win
timotimo no. no, it will very much not be. it will still be 100x slower than a regular native array 01:51
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timotimo do a small test up front and you'll see just how terrible performance of shaped arrays is right now 01:51
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timotimo wow, using the return value from a loop causes the program to run about 2x as long, and also eats up more than 2x more memory 01:55
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BenGoldberg If you use := instead of = for the array assignment, does it speed it up? 01:57
timotimo i don't have an array assignment at the moment; do you mean for the loop, or for a "..." call?
using int32 for the arrays makes memory usage a bit lower, but has nearly no impact on run time
BenGoldberg 'my @res = get_primes(10000000);' vs 'my @res := get_primes(10000000);' 01:59
Also for doing 'my @s = do loop ...' vs 'my @s := do loop ...' 02:00
timotimo the @s will be modified later on, so just putting a Seq in there won't fly 02:01
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timotimo no change between = and := 02:02
it halves maximum resident set size, but it doesn't make things faster
better than half, actually
BenGoldberg Ok, what about replacing the 'for @s' loop with 'return @s' 02:03
Hmm, need to do unshift(@s, 2), first, to make the results correct. 02:04
timotimo wouldn't that change semantics?
BenGoldberg ?
timotimo that for loop basically implements .grep(*.so) 02:05
BenGoldberg Oh, I see.
Ok, then how about unshifting 2 onto the front of @s, then doing 'return @s.grep: @.so;' 02:06
Without putting stuff in @r. Actually, I don't think @r is really necessary.
timotimo i'm trying
the "original"(?) python code has the result thing anonymous in a return clause 02:07
return [2] + [x for x in s if x]
BenGoldberg That can be mimiced with 'return 2, |(@s.grep: *.so);' ... I'm not sure which would be faster. 02:08
timotimo my attempt at that makes it slower and use more memory
i'm going to bed 02:10
BenGoldberg G'night, then.
timotimo i have a hot water bottle waiting for me in bed <3 02:11
have fun with the benchmark, if you're going to continue working on it :) 02:12
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sortiz m: use Test; my @a; my $p = @a; does-ok $p, Positional; # So far, so good 02:57
camelia rakudo-moar ec6c3b: OUTPUT«ok 1 - The object does role 'Positional'␤»
sortiz m: use Test; my @a; does-ok @a, Positional; # Missing signature?
camelia rakudo-moar ec6c3b: OUTPUT«ok 1 - The object does role 'Positional'␤»
sortiz Hmm
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MadcapJake what do you mean missing signature? 03:21
m: @a.^roles.say
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MadcapJake m: "hello?".say 03:22
camelia rakudo-moar ec6c3b: OUTPUT«5===SORRY!5=== Error while compiling /tmp/ORxwbtUUbj␤Variable '@a' is not declared␤at /tmp/ORxwbtUUbj:1␤------> 3<BOL>7⏏5@a.^roles.say␤» 03:23
rakudo-moar ec6c3b: OUTPUT«hello?␤»
MadcapJake m: my @a; @a.^roles.say 03:24
camelia rakudo-moar ec6c3b: OUTPUT«((Positional) (Iterable))␤»
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sortiz MadcapJake, nothing, a random glitch in the matrix ;-) 03:28
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sortiz I'm writing json-c's NativeCall bindings, and was testing the properties of my objects. :-) 03:30
MadcapJake ahh i see! :) if there was a glitch, the agents might be on to you! Get to a phone quickly! ;) 03:35
sortiz :P 03:36
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RabidGravy Boom! 06:08
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ufobat good morning :) 07:15
RabidGravy erp 07:17
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.oO( RabidGravy seems to like ERP systems :-)
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RabidGravy last time I worked with SAP it made me go blind or something 09:31
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stmuk SAP also made people rich 11:27
timotimo i didn't expect only a quarter screenful of irc to happen while i'm asleep :P 11:34
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nine_ It's a quiiiiet day 11:41
jnthn Not here it ain't. It was the day of the month they decided to test the air raid siren. :P 11:42
Or nuke siren, or whatever it's for.
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nine_ preferably at 6 in the morning? 11:43
jnthn No, at midday at least :)
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jnthn They anounce the test in English too, funnily enough, but the speaker is so bad that it took me a year of hearing the announcements to realize that part of it even was in English. :) 11:44
AlexDaniel yea, just using native ints in primes.p6 thingy makes it run in like 50% time
jnthn So...nativism trumps again... :P 11:45
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brrt puzzles whether that is a pun 11:51
AlexDaniel “for @s { @r.push($_) if $_ }” is significantly faster than “@r.append: @s.grep: {$_}” 11:54
nine_ I'm not entirely surprised
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AlexDaniel it seems like just pushing these numbers takes a lot of time 12:01
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AlexDaniel also, @a.append: @b is much faster than @a.push: |@b 12:04
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AlexDaniel m: my @a = 1..100000; my @b; @b.push: |@a 12:05
camelia rakudo-moar 480709: OUTPUT«Too many arguments in flattening array.␤ in block <unit> at /tmp/WYXkksBAXL line 1␤␤»
AlexDaniel mmmhm…
I haven't thought about it
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timotimo i suppose the reason for grep with a block is slower is because we don't have trace jit yet, which means it'll invoke a code object for every single test 12:09
whereas in the for + if that's in-line for free
moritz maybe laziness is to blame
jnthn `@a.push: |@b` is a pretty bad idea :) 12:10
timotimo hm, append won't try to eagerly nom the whole list?
that'd be a bad miss :)
or do we want it to act like "plan"?
jnthn It actually flattens all the arguments
Into the callsite
timotimo yes, that's pretty terrible 12:11
AlexDaniel @s .= grep({$_}); @r.append: @s; is slightly faster than everything
jnthn And produces a callsite descriptor along the way
timotimo it'd end up like a triple copy of the whole list
jnthn Yeah, plus making the huge callsite descriptor. And, worse, while the argument limit in MoarVM is fairly high, the one on the JVM is 255 iirc.
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AlexDaniel ah… well, some things work faster without native ints 12:22
m: my int $x = 2; $x /= 2; say $x 12:26
camelia rakudo-moar 480709: OUTPUT«This type cannot unbox to a native integer␤ in block <unit> at /tmp/RXCVNLBO3x line 1␤␤»
AlexDaniel is it ok?
timotimo yes, the GC time hardly gets reduced at all, which is because of all the IntLexRef objects being created and immediately tossed again
that's fine 12:27
m: my int $x = 2; $x div= 2; say $x
camelia rakudo-moar 480709: OUTPUT«1␤»
timotimo you want this anyway ^
AlexDaniel right
timotimo i'm still looking for the right peg to hang "turn this num into an int without going through Int" off of
it's just a matter of using the nqp op that i've already bound on a local branch, but how do i expose it to the user's code?
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ZoffixW What does rakudobrew rehash do? 12:29
timotimo i think it just rebuilds the scripts in bin/ that point "to the actual things" 12:30
ZoffixW I see
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AlexDaniel looking at this comparison again, I think that it is pretty stupid. If you look closely, then in both P5 and suggested P6 versions there is a temp array @r that is there for no reason 12:42
while in e.g. python version there is no such thing
in perl 6, getting rid of this @r array actually makes things significantly faster 12:43
RabidGravy gosh the chromaprint api is really rather simple
timotimo AlexDaniel: in the python version it returns [2] + [a for a in s if a] or something 12:49
which is equivalent to @r
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AlexDaniel timotimo: saving the result into array is a redundant step, which may have some impact 12:53
dalek osystem: bd5e63c | (Salvador Ortiz)++ | META.list:
Add JsonC to ecosystem.

NativeCall bindings to json-c library
AlexDaniel and if you use @s as an array of native ints, then indeed it does
timotimo right. you still need to filter it and put the 2 in front :)
the filter thing could surely be done easily with a two-pointer algorithm in-place, though 12:54
RabidGravy ah sortiz++
sortiz Yet another JSON module for Perl6 :-)
RabidGravy I looked at that a while back, decided it was too complicated to do quickly and for forgot about it 12:55
timotimo if it's a drop-in replacement for JSON::Fast, it'll probably eat its lunch :) 12:56
RabidGravy or at least it's breakfast
sortiz panda's projects.json is parsed in Parsed in 0.0034288s. 12:57
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ZoffixW sortiz++ 12:59
sortiz The idea is that the C library eat the file, and the unmarshaling is be lazy and on demand.
ZoffixW Now me need JSON::MaybeC :)
stmuk we need more YAML parsing (not that I like the format)! 13:00
ZoffixW Why?
stmuk I don't think there is any module to read it 13:02
RabidGravy I made one in C# once
ZoffixW ugexe, doesn't look like #86 got resolved. I'm still having the same issue. That's after nuking everything and starting from scratch (github.com/ugexe/zef/issues/86)
stmuk ZoffixW: or was the Q why I don't like YAML? :) 13:03
ZoffixW stmuk, no, you said "more", so I assumed we already had YAML and needed more :)
I don't like it either
sortiz Any code review/comments/suggestions will be appreciated. 13:04
ZoffixW It's the Python equivalent of configuration files 😂😂😂
stmuk yes the whitespace sensitivity is a misfeature
RabidGravy it was the new hotness back in, oh, 2002 13:05
timotimo we have one yaml module that doesn't work, iirc 13:06
stmuk YAMLish looks hopeful 13:07
sortiz The json-c library is a little more permissive than JSON::Fast, so five 'should fail to parse' tests fails. 13:08
AlexDaniel anyway, here is the what I got: gist.github.com/AlexDaniel/ce3c60e...bedea03ff5
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timotimo sortiz: that's not "permissive", that's "wrong" :) 13:08
AlexDaniel it runs about twice faster
but I am sure that there is a way to make it even faster if you manage to get rid of this .grep 13:09
sortiz timotimo, Indeed, but json-c is in github, so that can be fixed. ;-) 13:11
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ZoffixW sortiz, which tests are that? 13:11
I see JSON::Fast is broken and doesn't handle newer spec 13:12
timotimo oh? please elaborate
ZoffixW perl6 -MJSON::Fast -e 'from-json q{"foo"} error: 'a JSON string ought to be a list or an object
That's no longer true. Anything can be at top level
sortiz That is supported in JsonC. 13:13
ZoffixW rfc7159.net/rfc7159#rfc.section.2 (second paragraph, especially)
timotimo from when is that?
ZoffixW March 2014
timotimo oops. 13:14
RabidGravy ZoffixW, I'll alter the source-url in the App::ModuleSnap
AlexDaniel ZoffixW: but still no trailing commas allowed? :(
moritz JSON::Fast copied JSON::Tiny, which used to follow ECMA-404 13:15
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moritz later, JSON::Tiny relaxed its parsing 13:15
ZoffixW RabidGravy, alright. I'll be mentioning it in an upcoming article, and didn't want people having issues installing it :)
moritz ("copied" is wrong, it just implemented the same interface)
sortiz Right now JsonC is faiing t/01-parse.t's 75-76, 78, 80-81
RabidGravy I'll make it "git://github.com/jonathanstowe/App-ModuleSnap.git" which is the form that App::NoPaste uses 13:16
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grondilu m: say { $^n ?? $n*&?BLOCK($n-1) !! $n }(4) 14:16
camelia rakudo-moar 475063: OUTPUT«0␤»
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grondilu m: say { $^n ?? $n*&?BLOCK($n-1) !! 1 }(4) 14:16
camelia rakudo-moar 475063: OUTPUT«24␤»
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grondilu I remember long time ago I wanted to talk about tail recursion and asked if Perl 6 would support it. You guys told me that it would probably not for various complicated reasons. We have at least two kinds of Callables structures though: Sub and Block. Couldn't at least one of them support tail recursion optimization? So that we can have efficient recursive functions? 14:18
jnthn m: say { [*] 1..$^n }(4) # it's so esay to write this one iterative :P 14:19
camelia rakudo-moar 475063: OUTPUT«24␤»
timotimo my uneducated opinion is that once we have trace jit, TCO becomes a potential possibility 14:20
probably a case of "SMOP", with all the things that entails
jnthn We don't in general know if anything "downstream" will do things like CALLER::
I think the question isn't "can we do TCO some of the time" 14:21
It's "can we do it predictably enough that can rely on it happening"
Can we do it at all is "surely yes", it's the latter I'm highly doubtful about.
timotimo oof. 14:22
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timotimo right, fair enough 14:22
grondilu Could we not have a Calleable type that would prohibit anything that's incompatible with TCO?
jnthn Even if that's a dynamic prohibition?
(You'd get a runtime exception for doing something incompatible with it, that is) 14:23
grondilu jnthn: I don't know, but you make it sound like TCO is impossible or something. Some languages do it, just do whatever they do.
jnthn That's stupid. 14:24
grondilu rude
jnthn Other languages can do it because they made the trade-offs.
Saying "in return we can't do X"
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[Coke] I think a better question than "can we do TCO" is "what is the plan for making rakudo faster". 14:25
MadcapJake sub tco($arg) is MONKEY-TAIL { ... }
timotimo accessing a caller's lexical variables, for example ... (only if they are marked dynamic, of course)
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jnthn Language design is always trade-offs. 14:25
pmichaud good morning #perl6 14:26
grondilu my concern is that there are function that are very much easier to write recursively, but we always end up not writing them because of performance issues. That's very LTA.
jnthn And the langs I know where you can rely on tail calls all made it so you can analyze that.
o/ pmichaud
MadcapJake jnthn: could you explain a bit what the trade-offs are for TCO? I'm not following what the CALLER:: argument means
jnthn MadcapJake: In various languages, it's possible to staticly analyze things such that you can rewrite a recursion into an iteration. 14:27
MadcapJake: That relies on you knowing that you won't break anything in the process of doing so.
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jnthn MadcapJake: And as a result of the rules around when it happens being fairly simple, folks can write code relying on it. 14:28
In Perl 6, various features make that static analysis fraught while others mean we simply can't do it.
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pyrimidine jnthn: re: recursion to iteration, IIRC there is a fair amount in Higher Order Perl that covers doing so (for p5 of course) 14:28
pmichaud aren't C<nextsame> and C<nextwith> supposed to help with tailcalls? Or is that a fossil? (Or are we strictly discussing automatic TCO?) 14:29
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jnthn The moment you make a method call, it's late-bound and you don't know whether that code will do anything, like access CALLER::. 14:29
pmichaud: They're for iterating through pre-determined candidate lists. They potentially could make use of tail call optimization, though you could construct cases where the optimization would break things. 14:30
pmichaud I guess nextsame/nextwith aren't recursive tailcalls. But perhaps they point the way to there.
ZoffixW Is anyone feeling adventurous and wants to add Perl 6 to CodeMirror? :P codemirror.net/mode/index.html
jnthn method foo() { my $*x = 42; nextsame() }
Does the thing you nextsame to see $*x or not? 14:31
ZoffixW The Perl 5 version is 800 lines long :( Perl 6 version would probably be much larger: github.com/codemirror/CodeMirror/b...rl/perl.js
MadcapJake ZoffixW: I'm partway through a highlightjs mode but I got discouraged when I discovered heredocs were impossible
timotimo i think we already have a bit of codemirror for perl6
jnthn (The answer today is "yes"; replacing the callframe would change that answer, for example)
ZoffixW MadcapJake, :( 14:32
timotimo github.com/azawawi/farabi6/blob/ma...l6-mode.js <- ZoffixW
MadcapJake timotimo: that isn't usable actually, it's basically a copy-and-paste of perl5-mode
jnthn nextsame today functions as return callsame(...)
ZoffixW Yey! timotimo++ azawawi++
timotimo OK, sorry about that
pmichaud jnthn: and yes, I'd expect nextsame to be that way.
MadcapJake ZoffixW: do not use that, azawawi informed me that it's not implemented beyond just copying perl5-mode into a new file
jnthn It's really tail calls as a language feature, vs. tail calls as an optimization. 14:33
ZoffixW MadcapJake, aw. Too bad
jnthn The latter I'm pretty sure we could do in some cases; the former is a lot harder than "just copy what another language does". 14:34
pmichaud jnthn: agreed
ZoffixW MadcapJake, how come heredocs are impossible?
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pyrimidine jnthn: could you indicate a method can be TCO, e.g. method foo() is tco { ... } 14:34
MadcapJake ZoffixW: the highlight.js lexing engine doesn't support capturing delimiters and reusing them
ZoffixW Ah 14:35
MadcapJake there's an issue in their tracker wrt to it and the author basically says "not possible and we're not implementing it any time soon"
ZoffixW :/
jnthn pyrimidine: What would that actually do?
I mean, sure we can indicate things, but what semantics go with it? 14:36
MadcapJake ZoffixW: I started a CodeMirror perl6 mode a little ways back actually (I forgot about it :). I'll try and get it finished this week (perhaps more likely next)
ZoffixW Sweet. No rush :)
jnthn If anything, the "this is a tailcall" mark would want to go on the call that should function that way.
ufobat ZoffixW, thanks for the PR
jnthn Which would mean you're explicitly saying "and if anything downstream isn't OK with that, it's my fault" 14:37
pyrimidine jnthn: yeah, true
ZoffixW ufobat, no problem
timotimo there's monsters in the basement preventing me from TCO! :(
jnthn Which, as pmichaud points out, is kinda taking the nextsame/callsame approach by making explicit what you want to happen 14:38
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CIAvash github.com/jneen/rouge also needs a Perl 6 lexer. It's being used in Gitlab and Jekyll 14:38
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dalek pan style="color: #395be5">perl6-examples: 8e9d84e | (Tom Browder)++ | Makefile:
module 'Web::Request' not needed
perl6-examples: 1e2191e | (Tom Browder)++ | categories/99-problems/P40-rhebus.pl:
perl6-examples: add tilde to remove parens in output; remove last integer as input (or could add it to the test output if desired)
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MadcapJake jnthn: In Perl 6, if you use {call,next}{with,same} and multi-dispatch heavily, will you run into issues? Because I think TCO is really about supporting that recursive paradigm more than anything and if we can support it without TCO then it's kind of a moot point. 14:43
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MadcapJake CIAvash: ok it's on the todolist! I usually only have so much syntax highlighting juice in any given month though :P 14:44
jnthn MadcapJake: {call,next}{with,same} aren't for recursing anyway, they're through walking through (usually short, pre-destined) lists of implementations, so you can defer control to a more general candidate. 14:45
CIAvash MadcapJake: nice :) 14:46
jnthn MadcapJake: If you write heavily recursive stuff today - yes, you'll allocate a lot of stack frames.
And yes, tailcall as an explicit language feature is a lot more hopeful in Perl 6 than TCO.
MadcapJake jnthn: ok so those keywords are more about the dispatching than about recursing. specifically call{with,same} would seem related to recursion, at least at first glance. 14:47
nine_ I think there's still the endless loop issue with nextsame 14:48
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jnthn nine_: Yeah, that one should never be able to happen. I think I figured out how to fix it though: capture the frame that set the dispatcher. 14:48
nine_: And check that it's the caller of the thing trying to take it.
Then it won't be stolen by accident 14:49
Alternatively, we might be able to fix it with better code-gen.
nine_ jnthn: sounds like a step or two above my pay grade, so I'm no longer ashamed that I couldn't fix it :)
jnthn Just by forcing the takedispatcher to be earlier.
nine_: I dunno, I think you've done plenty of trickeir things ;-)
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nine_ Well I guess things usually seem much less tricky after you've done them ;) 14:50
jnthn Don't they just...
jnthn looks forward to the current invocation changes he's doing seeming much less tricky... 14:52
MadcapJake I think another point wrt tailcall/TCO: Perl 6 has much more powerful iterative facilities that make recursion not so necessary.
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pmurias MadcapJake: TCO is only truly necessary in functional languages 14:55
the python philosophy is that they won't implement it because it's not worth having worse stack traces 14:58
MadcapJake pmurias: yeah, as much as I like to think of Perl 6 as multi-paradigm, it seems there are certain things that require you to become entrenched in a particular paradigm (like TCO here). 14:59
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MadcapJake interesting: ES6 has TCO actually www.2ality.com/2015/06/tail-call-op...ation.html 15:01
ZoffixW MadcapJake, I think azawawi did more work on the CodeMirror thing. It looks usable enough: i.imgur.com/DxB7sNf.png 15:03
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ZoffixW Still highlighted code inside a heredoc as code, but at least nothing is broken (like in SubLime text 2 :P) 15:04
pmurias MadcapJake: according to the v8 team the want to change the spec to have implicit tail calls
MadcapJake yeah it works but it's mostly just perl 5 with a few added keywords. one negative is that perl 5 keywords and such will also be highlighted
pmurias: what does that mean? 15:05
ZoffixW JS spec? 15:06
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pmurias MadcapJake: you will have to syntactically mark that you want to have a tail call 15:07
nine_ explicit not implicit 15:09
pmurias nine_: yes, sorry
what they want to have: github.com/tc39/proposal-ptc-syntax
MadcapJake ahh yeah that's what my confusion was, I think that's a fine idea 15:12
brrt it's weird to specify an optimization in the language, i'd think 15:15
ZoffixW Well, we do have is cached already :P 15:17
grondilu and 'is pure' (?) 15:18
pmurias brrt: tail calls change semantics
brrt hmm, not necessarily
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pmurias brrt: when they eat your stack trace they do 15:19
brrt or, well, it depends on whether your semantics include this notion of the stack
keep a parameter 'i'm N tail calls deep', reconstruct the stack trace, done :-)
actually, call trace 15:20
but anyway
i'm nitpicking
perlpilot brrt: have you ever had to debug a Perl 5 program where perl optimized away some of your call frames?
brrt my point is that the stack is an implicit assumption of routine local storage, which is not necessary to specify in a language
no, haven't, actually
that's using goto right?