No entry for existential types in "A Tour of Scala"

Not to hijack your thread, but is there a PDF version of "A Tour Of Scala".

Mohamed

Alex Cruise wrote:
> "A Tour of Scala" (http://www.scala-lang.org/node/104) is very nice
> but makes no mention of existential types.
>
> If I understood anything about them I would volunteer to write it, but
> maybe someone could reply to this post with a reasonable strawman
> proposal for such a page, then we could kick it into shape?
>
> Thanks,
>
> -0xe1a

There used to be a separate pdf version of the Tour, but it is no longer
maintained. You can get a printable copy of the whole Tour, automatically
extracted from the website pages, at:

http://www.scala-lang.org/print/book/export/html/104

The old PDF, which is however no longer up-to-date, can still be obtained from:

http://www.scala-lang.org/docu/files/ScalaTour.pdf

Toni

Mohamed Bana wrote:
> Not to hijack your thread, but is there a PDF version of "A Tour Of Scala".
>
> Mohamed
>
> Alex Cruise wrote:
>> "A Tour of Scala" (http://www.scala-lang.org/node/104) is very nice
>> but makes no mention of existential types.
>>
>> If I understood anything about them I would volunteer to write it, but
>> maybe someone could reply to this post with a reasonable strawman
>> proposal for such a page, then we could kick it into shape?
>>
>> Thanks,
>>
>> -0xe1a
>
>

On Friday March 6 2009, Antonio Cunei wrote:
> There used to be a separate pdf version of the Tour, but it is no
> longer maintained. You can get a printable copy of the whole Tour,
> automatically extracted from the website pages, at:
>
> http://www.scala-lang.org/print/book/export/html/104

To add to this, I discovered that when I tried to print this page from
Firefox 3.0.6, the images (the Scala logotype and the class diagram)
would not render.

However, when I converted that page to PDF using Firefox's built-in
print-to-PDF function the resulting PDF retained the images and when
printed they were rendered on the paper. (Firefox's print-to-PostScript
also failed to retain the graphics).

I'll also note that the PDF conversion performed by Firefox was
distinctly superior to that provided by the on-line conversion
accessible via the PDF Download (a browser plug-in) vendor Web site.

> The old PDF, which is however no longer up-to-date, can still be
> obtained from:
>
> http://www.scala-lang.org/docu/files/ScalaTour.pdf
>
> Toni

Randall Schulz

Arrgh wrote:
>
> "A Tour of Scala" (http://www.scala-lang.org/node/104) is very nice but
> makes no mention of existential types.
>
> If I understood anything about them I would volunteer to write it, but
> maybe someone could reply to this post with a reasonable strawman
> proposal for such a page, then we could kick it into shape?
>
> Thanks,
>
> -0xe1a
>
>
Quite some time ago there was a discussion and Bill Venners did mention some
interesting things ( for me):
he said something like: Scala Typsystem isn't too great from chis personal
experince he did encounter:
* nominal types
* typ parameters
* function types
* traits
* singleton objects
* variance
* visibility ranges
* structual types
* types of higher kinds
* pathdepended types
* existential types
* abstract types
* typinference

i found it so usefull that i put it on wikipedia

On 03/06/2009 11:31 AM, andreas s. wrote:
> Quite some time ago there was a discussion and Bill Venners did
> mention some interesting things ( for me): he said something like:
> Scala Typsystem isn't too great from chis personal experince ...
I suspect Bill's perspective would be different today, since he's the
publisher and a co-author of the first Scala book. :)

Let's try to re-rail this thread: Can we come up with a concise
description of:
- what existential types are;
- what situations they're useful in;
- some "before and after" examples that show the improvements that come
from using existentials.

Burak's article from a couple years ago
(http://lamp.epfl.ch/~emir/bqbase/2007/06/13/existentials.html) seems
like a pretty good start, but it could use some summarizing (and dumbing
down ;)

-0xe1a

no guarantees, but here's a PDF http://filebin.ca/rkdykd/tour.pdf or http://filebin.ca/rkdykd.  i've attached the TeX file if you want to typeset it yourself.

// convert from html to TeX
$ pandoc -w context 104.html -o tour.tex

// produces the PDF
$ texexec tour

you'll need

pandoc from http://johnmacfarlane.net/pandoc/
texlive 2008 (maybe 2007 may also work)


Mohamed

Randall R Schulz wrote:

200903061009 [dot] 30840 [dot] rschulz [at] sonic [dot] net" type="cite">

On Friday March 6 2009, Antonio Cunei wrote:
  

There used to be a separate pdf version of the Tour, but it is no
longer maintained. You can get a printable copy of the whole Tour,
automatically extracted from the website pages, at:

http://www.scala-lang.org/print/book/export/html/104
    

To add to this, I discovered that when I tried to print this page from 
Firefox 3.0.6, the images (the Scala logotype and the class diagram) 
would not render.

However, when I converted that page to PDF using Firefox's built-in 
print-to-PDF function the resulting PDF retained the images and when 
printed they were rendered on the paper. (Firefox's print-to-PostScript 
also failed to retain the graphics).

I'll also note that the PDF conversion performed by Firefox was 
distinctly superior to that provided by the on-line conversion 
accessible via the PDF Download (a browser plug-in) vendor Web site.


  

The old PDF, which is however no longer up-to-date, can still be
obtained from:

http://www.scala-lang.org/docu/files/ScalaTour.pdf

Toni
    

Randall Schulz
  

On Fri, Mar 6, 2009 at 11:46 AM, Alex Cruise <alex@cluonflux.com> wrote:

Burak's article from a couple years ago (http://lamp.epfl.ch/~emir/bqbase/2007/06/13/existentials.html) seems like a pretty good start, but it could use some summarizing (and dumbing down ;)

Another good source would be David MacIver's blog post here:
http://www.drmaciver.com/2008/03/existential-types-in-scala/

alex