Is there a JavaScript parser somewhere?
by Alexandre Bergel
Just wondering…
Cheers,
Alexandre
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Alexandre Bergel http://www.bergel.eu
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7 years, 7 months
sQuick?
by Alexandre Bergel
Hi!
I see the project: github.com/jig08/sQuick_new
Can I use it as a replacement of Spotlight on OS X? Is it means to replace it?
Cheers,
Alexandre
--
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Alexandre Bergel http://www.bergel.eu
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7 years, 7 months
Re: [Pharo-dev] PetitParser speed and cost of PPFailure
by Tudor Girba
You will probably have more chances to get a response on the Moose mailing
list.
Cheers,
Doru
On Sun, Aug 16, 2015 at 5:58 PM, Holger Freyther <holger(a)freyther.de> wrote:
> Hi,
>
> once again I am not sure if this is the right list. The first parser I
> wrote using
> PetitParser was a SIP (and then MGCP) parser. I have recently ported[1] the
> code to Pharo and with Pharo it is very tempting to Use
> BlockClosure>>#bench
> to get an idea of the speed.
>
>
> I have two performance “issues” and wonder if others hand similar issues
> with
> PetitParser and if there is a general approach to this.
>
>
>
> 1.) Combining two PPCharsetPredicates does not combine the “classification”
> table it had. One could create a PPPredicateObjectParser subclass that is
> special casing >>#/ to build a combined classification table.
>
>
> 2.) When blindly following a BNF enumeration of "A or B or C or D or E
> or CatchAll” and each “A, B” follow common pattern (e.g. token COLON value)
> one pays a high cost in the backtracking and constructing the PPFailure for
> each failed case.
>
> In my SIPGrammar I have action parsers for To ==>.. From ==> and would
> like to keep that. At the same time I would be happy if the token in front
> of the
> colon is only consumed once and then delegated to the right parser and if
> that
> one failed use the ‘catch all’ one.
>
> I don’t know which abstraction would be needed to allow creating optimized
> PetitParsers for such grammars.
>
> sorry for the long mail, long details and context is below.
>
>
> kind regards
> holger
>
>
>
>
>
>
> Full details:
>
>
> 1.) CharSetPredicate
>
> | aParser bParser combinedParser aTime bTime cTime |
>
> aParser := #digit asParser.
> bParser := #letter asParser.
> combinedParser := aParser / bParser.
>
> aTime := [ aParser parse: 'b'] bench.
> bTime := [ bParser parse: 'b'] bench.
> cTime := [ combinedParser parse: 'b'] bench.
> { aTime. bTime. cTime }
>
> cTime is bounded by the time execution time of of the slowest
> of these parsers + overhead (e.g. PPFailure creation).
>
> e.g.
>
> #('559,000 per second.' '1,010,000 per second.' '429,000 per second.')
>
> With a proof of concept PPPredicateCharSetParser
>
> #('1,330,000 per second.' '1,550,000 per second.' '1,580,000 per second.’)
>
> The noise is pretty string here but what is important is that bParser and
> the
> combinedParser are in the same ballpark.
>
> 2.) Choice Parser
>
>
>
> The BNF grammar of the parser is roughly:
>
> Request = Request-Line
> *( message-header )
> CRLF
> [ message-body ]
>
> message-header = (Accept
> …
> / To
> / From
> / Via
> / extension-header) CRLF
>
> Alert-Info = "Alert-Info" HCOLON alert-param *(COMMA alert-param)
> Accept = "Accept" HCOLON
> [ accept-range *(COMMA accept-range) ]
>
>
> So there can be several lines of “message-header”. And each method header
> starts with a token/word, a colon and then the parameter.
> “extension-header”
> is kind of a catch all if no other rule matched. E.g. if a client sends a
> To which is
> wrongly encoded it would end up with the extension-header.
>
> I transferred the above naively to PetitParser and end up with something
> like
> parsing ~500 messages a second. The main cost appears to come from the
> choice parser that needs to create a PetitFailure all the time. E.g. if
> you have a
> line like this:
>
> ‘From: “Holger Freyther” <sip:323234@foo.de>’
>
> The choice parser will start with the “Accept” rule, parse the token
> (“From” and
> then create a PPFailure, then … rules, then “To”, parse the token.. So we
> have
> parsing the same token more than once and creating PPFailures all the
> time. I
> ended up creating a custom parser that will peek the token, have a
> horrible chain
> of token = ‘XYZ’ ifTrue and then dispatch to the other rule.
>
> It would be nice if PetitParser could be taught to only parse the token
> once and
> then delegate to the param rule. E.g. a PPAnyOfParser that allows to
> specify the
> token to match, the parser to continue with and a fallback parser?
>
>
>
> [1]
> http://smalltalkhub.com/#!/~osmocom/SIP
> http://smalltalkhub.com/#!/~osmocom/MGCP
>
--
www.tudorgirba.com
"Every thing has its own flow"
7 years, 7 months
Slowdown?
by Alexandre Bergel
Hi!
I have noticed a slowdown in moose. Opening a menu is now particularly slow. Here is a
https://dl.dropboxusercontent.com/u/31543901/TMP/slowdown.mov
I have just tried on Pharo 5, and it looks like to have a similar problem.
Cheers,
Alexandre
--
_,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:
Alexandre Bergel http://www.bergel.eu
^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
7 years, 7 months
Worried...
by Alexandre Bergel
Hi!
I am a bit worried.
The jenkins for Moose 6.0 has not been green for ages.
I am using a fresh 6.0, and I get error when tracing in the debugger:
-=-=-=-=-=-=-=-=-=-=-=-=
DebuggerMethodMapOpal >> tempNamesForContext: aContext
"Answer an Array of all the temp names in scope in aContext starting with
the home's first local (the first argument or first temporary if no arguments)."
^ aContext sourceNode scope allTempNames.
-=-=-=-=-=-=-=-=-=-=-=-=
#scope is sent to nil. A good starting point would be to have the jenkins green back. Having it yellow for too long is not constructive.
cheers,
Alexandre
--
_,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:
Alexandre Bergel http://www.bergel.eu
^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
7 years, 7 months
Stack plot
by Alexandre Bergel
Hi!
Milton worked on a StackPlot builder.
This is currently highly prototypal.
Inspect the expression:
RTExperimentalExample new exampleStackOnRoassal
It gives something like, which shows the amount of code subclasses of RTShape:
Pretty cool!
Many other examples are contained in the class RTExperimentalExample
It is worth having a look at them.
And yes, it is exportable to HTML.
Cheers,
Alexandre
--
_,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:
Alexandre Bergel http://www.bergel.eu
^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
7 years, 7 months
very strange error with do: !!!
by Nicolas Anquetil
How is this possible?
aCollection is an array with 1 element (an AdaParameter ...)
but each in the do: block contains nil (so the add: gives a DNU) !?!?!?
I have no idea how this can be possible
Any clue
nicolas
7 years, 7 months
simple question about OSProcress
by Alexandre Bergel
Hi!
I am considering in using OSProcess to run an external application.
I have tried:
OSProcess waitForCommand: 'ls -l’
but this expression never return a value.
I also tried:
OSProcess command: 'ls -l /etc’
But it returns an ExternalUnixOSProcess. I am not sure what I can do with this. How can I get the result of the unix command?
Sorry if these questions looks naive :-)
Cheers,
Alexandre
--
_,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:
Alexandre Bergel http://www.bergel.eu
^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
7 years, 7 months
