Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Will Jukes]

I went ahead and added some info on the difference between Racket and
Python appends to https://github.com/racket/racket/wiki/Python-to-Racket .
Sorry to whoever for the salvo of poorly documented revisions.

On Sun, Feb 17, 2019 at 12:21 AM David Van Horn  wrote:

> I've updated the docs to get to the point faster with some early examples.
>
> http://dvanhorn.github.io/ralist/
>
> David
>
>
> On Sat, Feb 16, 2019 at 5:21 PM John Clements 
> wrote:
>
>> I struggled with whether to send that message… I saw the name, “random
>> access lists”, thought, “hmm, I wonder what that would like”, and clicked
>> on the link. I wound up reading a bit about whether I should use (first
>> impresssion) superficial or in-depth contracts, and ran out of steam pretty
>> quickly. Ultimately, of course, the real issue is that your documentation
>> wasn’t designed to help python programmers jump into their first experience
>> with Racket, but a link to your documentation has essentially just made you
>> an involuntary ambassador.
>>
>>
>> John
>>
>> > On Feb 16, 2019, at 14:00, David Van Horn  wrote:
>> >
>> > There are several examples for every function provided by the ralist
>> library.  (And it's almost verbatim what's in the Racket reference for
>> pairs and lists.)
>> >
>> > But... I can add some early examples.  No problem.
>> >
>> > David
>> >
>> > On Sat, Feb 16, 2019, 4:00 PM John Clements 
>> wrote:
>> > The pointer to RaLists would be much more enticing if we could convince
>> David Van Horn to begin his documentation with a couple of small examples….
>> >
>> > John
>> >
>> > > On Feb 13, 2019, at 14:35, Stephen De Gabrielle <
>> spdegabrie...@gmail.com> wrote:
>> > >
>> > > Thanks
>> > >
>> > > I should note that anyone with a GitHub account can edit
>> https://github.com/racket/racket/wiki/Python-to-Racket
>> > >
>> > > S.
>> > >
>> > > On Wed, 13 Feb 2019 at 21:26, Matthias Felleisen <
>> matth...@felleisen.org> wrote:
>> > >
>> > > Not until there’s demand. I think we do see demand for Python
>> transfers.
>> > >
>> > >
>> > >
>> > > > On Feb 13, 2019, at 3:11 PM, Stephen De Gabrielle <
>> spdegabrie...@gmail.com> wrote:
>> > > >
>> > > > Should there be similar pages for Javascript, Java,C#, C/C++, Ruby,
>> PHP, Visual Basic, Scratch and Haskell?
>> > > >
>> > > > S.
>> > > >
>> > > > On Wed, Feb 13, 2019 at 8:03 PM Stephen De Gabrielle <
>> spdegabrie...@gmail.com> wrote:
>> > > > I created a DRAFT page on the Racket GitHub wiki:
>> > > >   https://github.com/racket/racket/wiki/Python-to-Racket
>> > > > It links to a 'Choosing a data structure' page
>> https://github.com/racket/racket/wiki/Choosing-a-data-structure
>> > > > - this just as copy of the table created by Jens Axel Søgaard at:
>> https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
>> )
>> > > >
>> > > > Please edit/delete as you see fit
>> > > >
>> > > > Kind regards
>> > > > Stephen
>> > > >
>> > > >
>> > > > On Tue, Feb 12, 2019 at 5:20 PM Matthias Felleisen <
>> matth...@felleisen.org> wrote:
>> > > >
>> > > > This is perfect! Thanks — Matthias
>> > > >
>> > > >
>> > > >
>> > > >
>> > > > > On Feb 11, 2019, at 11:04 PM, Claes Wallin (韋嘉誠) <
>> cla...@gmail.com> wrote:
>> > > > >
>> > > > > For anyone creating such a web page for Python to Racket
>> specifically,
>> > > > > there is probably a great deal of inspiration, and reminders of
>> > > > > stumbling blocks, to be found in Arne Babenhauserheide's
>> > > > > https://www.draketo.de/py2guile book (available online for free)
>> about
>> > > > > going from Python to Guile Scheme.
>> > > > >
>> > > > > --
>> > > > >   /c
>> > > > >
>> > > > > On Sun, Feb 3, 2019 at 7:00 AM Matthias Felleisen
>> > > > >  wrote:
>> > > > >> Racket needs *you*. Please.
>> > > > >>
>> > > > >> The proper approach is to have short pages for different
>> language immigration groups: Python and R come to mind as obvious examples
>> but I am sure there are others.
>> > > > >>
>> > > > >> What I mean is we need help and *you* can help. Let me explain
>> it with the Python example:
>> > > > >>
>> > > > >> 1. Set up a page (wiki?) called “From Python to Racket”
>> > > > >>
>> > > > >> 2. Create two sections that are immediately visible from the top:
>> > > > >>
>> > > > >>— idioms
>> > > > >>— performance pitfalls
>> > > > >>
>> > > > >> 3. In the specific case of Python, the second subsection needs
>> to start with a subsection on
>> > > > >>
>> > > > >>— Python Lists aren’t Racket Lists
>> > > > >>— then point to data/ralis and show how to transliterate
>> the loop/append example like this
>> > > > >>— optionally also show the more native Racket idiom
>> > > > >>
>> > > > >> 4. When anyone observers another blog/social media/whatever post
>> on Racket is slow because I come from Python,
>> > > > >>
>> > > > >>(a) point the posters to the page  or
>> > > > >>(b) if it is a new case, write a 

Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[David Van Horn]

I've updated the docs to get to the point faster with some early examples.

http://dvanhorn.github.io/ralist/

David


On Sat, Feb 16, 2019 at 5:21 PM John Clements 
wrote:

> I struggled with whether to send that message… I saw the name, “random
> access lists”, thought, “hmm, I wonder what that would like”, and clicked
> on the link. I wound up reading a bit about whether I should use (first
> impresssion) superficial or in-depth contracts, and ran out of steam pretty
> quickly. Ultimately, of course, the real issue is that your documentation
> wasn’t designed to help python programmers jump into their first experience
> with Racket, but a link to your documentation has essentially just made you
> an involuntary ambassador.
>
>
> John
>
> > On Feb 16, 2019, at 14:00, David Van Horn  wrote:
> >
> > There are several examples for every function provided by the ralist
> library.  (And it's almost verbatim what's in the Racket reference for
> pairs and lists.)
> >
> > But... I can add some early examples.  No problem.
> >
> > David
> >
> > On Sat, Feb 16, 2019, 4:00 PM John Clements 
> wrote:
> > The pointer to RaLists would be much more enticing if we could convince
> David Van Horn to begin his documentation with a couple of small examples….
> >
> > John
> >
> > > On Feb 13, 2019, at 14:35, Stephen De Gabrielle <
> spdegabrie...@gmail.com> wrote:
> > >
> > > Thanks
> > >
> > > I should note that anyone with a GitHub account can edit
> https://github.com/racket/racket/wiki/Python-to-Racket
> > >
> > > S.
> > >
> > > On Wed, 13 Feb 2019 at 21:26, Matthias Felleisen <
> matth...@felleisen.org> wrote:
> > >
> > > Not until there’s demand. I think we do see demand for Python
> transfers.
> > >
> > >
> > >
> > > > On Feb 13, 2019, at 3:11 PM, Stephen De Gabrielle <
> spdegabrie...@gmail.com> wrote:
> > > >
> > > > Should there be similar pages for Javascript, Java,C#, C/C++, Ruby,
> PHP, Visual Basic, Scratch and Haskell?
> > > >
> > > > S.
> > > >
> > > > On Wed, Feb 13, 2019 at 8:03 PM Stephen De Gabrielle <
> spdegabrie...@gmail.com> wrote:
> > > > I created a DRAFT page on the Racket GitHub wiki:
> > > >   https://github.com/racket/racket/wiki/Python-to-Racket
> > > > It links to a 'Choosing a data structure' page
> https://github.com/racket/racket/wiki/Choosing-a-data-structure
> > > > - this just as copy of the table created by Jens Axel Søgaard at:
> https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
> )
> > > >
> > > > Please edit/delete as you see fit
> > > >
> > > > Kind regards
> > > > Stephen
> > > >
> > > >
> > > > On Tue, Feb 12, 2019 at 5:20 PM Matthias Felleisen <
> matth...@felleisen.org> wrote:
> > > >
> > > > This is perfect! Thanks — Matthias
> > > >
> > > >
> > > >
> > > >
> > > > > On Feb 11, 2019, at 11:04 PM, Claes Wallin (韋嘉誠) 
> wrote:
> > > > >
> > > > > For anyone creating such a web page for Python to Racket
> specifically,
> > > > > there is probably a great deal of inspiration, and reminders of
> > > > > stumbling blocks, to be found in Arne Babenhauserheide's
> > > > > https://www.draketo.de/py2guile book (available online for free)
> about
> > > > > going from Python to Guile Scheme.
> > > > >
> > > > > --
> > > > >   /c
> > > > >
> > > > > On Sun, Feb 3, 2019 at 7:00 AM Matthias Felleisen
> > > > >  wrote:
> > > > >> Racket needs *you*. Please.
> > > > >>
> > > > >> The proper approach is to have short pages for different language
> immigration groups: Python and R come to mind as obvious examples but I am
> sure there are others.
> > > > >>
> > > > >> What I mean is we need help and *you* can help. Let me explain it
> with the Python example:
> > > > >>
> > > > >> 1. Set up a page (wiki?) called “From Python to Racket”
> > > > >>
> > > > >> 2. Create two sections that are immediately visible from the top:
> > > > >>
> > > > >>— idioms
> > > > >>— performance pitfalls
> > > > >>
> > > > >> 3. In the specific case of Python, the second subsection needs to
> start with a subsection on
> > > > >>
> > > > >>— Python Lists aren’t Racket Lists
> > > > >>— then point to data/ralis and show how to transliterate
> the loop/append example like this
> > > > >>— optionally also show the more native Racket idiom
> > > > >>
> > > > >> 4. When anyone observers another blog/social media/whatever post
> on Racket is slow because I come from Python,
> > > > >>
> > > > >>(a) point the posters to the page  or
> > > > >>(b) if it is a new case, write a section for this example
> then do (a)
> > > > >>
> > > > >>
> > > > >> If you want to help advertise Racket to others, this is an
> excellent way of helping out.
> > > > >>
> > > > >> Thanks — Matthias
> > > > >>
> > > > >> [[ p.s. For my very first Python program (a couple of days before
> meeting with GvR), I used Python’s append and was annoyed beyond belief. ]]
> > > > >>
> > > > >>
> > > > >> --
> > > > >> You received 

Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

['John Clements' via Racket Users]

I struggled with whether to send that message… I saw the name, “random access 
lists”, thought, “hmm, I wonder what that would like”, and clicked on the link. 
I wound up reading a bit about whether I should use (first impresssion) 
superficial or in-depth contracts, and ran out of steam pretty quickly. 
Ultimately, of course, the real issue is that your documentation wasn’t 
designed to help python programmers jump into their first experience with 
Racket, but a link to your documentation has essentially just made you an 
involuntary ambassador.


John

> On Feb 16, 2019, at 14:00, David Van Horn  wrote:
> 
> There are several examples for every function provided by the ralist library. 
>  (And it's almost verbatim what's in the Racket reference for pairs and 
> lists.)
> 
> But... I can add some early examples.  No problem.
> 
> David
> 
> On Sat, Feb 16, 2019, 4:00 PM John Clements  wrote:
> The pointer to RaLists would be much more enticing if we could convince David 
> Van Horn to begin his documentation with a couple of small examples…. 
> 
> John
> 
> > On Feb 13, 2019, at 14:35, Stephen De Gabrielle  
> > wrote:
> > 
> > Thanks 
> > 
> > I should note that anyone with a GitHub account can edit 
> > https://github.com/racket/racket/wiki/Python-to-Racket
> > 
> > S.
> > 
> > On Wed, 13 Feb 2019 at 21:26, Matthias Felleisen  
> > wrote:
> > 
> > Not until there’s demand. I think we do see demand for Python transfers. 
> > 
> > 
> > 
> > > On Feb 13, 2019, at 3:11 PM, Stephen De Gabrielle 
> > >  wrote:
> > > 
> > > Should there be similar pages for Javascript, Java,C#, C/C++, Ruby, PHP, 
> > > Visual Basic, Scratch and Haskell?
> > > 
> > > S.
> > > 
> > > On Wed, Feb 13, 2019 at 8:03 PM Stephen De Gabrielle 
> > >  wrote:
> > > I created a DRAFT page on the Racket GitHub wiki:
> > >   https://github.com/racket/racket/wiki/Python-to-Racket
> > > It links to a 'Choosing a data structure' page 
> > > https://github.com/racket/racket/wiki/Choosing-a-data-structure
> > > - this just as copy of the table created by Jens Axel Søgaard at: 
> > > https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146)
> > > 
> > > Please edit/delete as you see fit
> > > 
> > > Kind regards
> > > Stephen
> > > 
> > > 
> > > On Tue, Feb 12, 2019 at 5:20 PM Matthias Felleisen 
> > >  wrote:
> > > 
> > > This is perfect! Thanks — Matthias
> > > 
> > > 
> > > 
> > > 
> > > > On Feb 11, 2019, at 11:04 PM, Claes Wallin (韋嘉誠)  
> > > > wrote:
> > > > 
> > > > For anyone creating such a web page for Python to Racket specifically,
> > > > there is probably a great deal of inspiration, and reminders of
> > > > stumbling blocks, to be found in Arne Babenhauserheide's
> > > > https://www.draketo.de/py2guile book (available online for free) about
> > > > going from Python to Guile Scheme.
> > > > 
> > > > -- 
> > > >   /c
> > > > 
> > > > On Sun, Feb 3, 2019 at 7:00 AM Matthias Felleisen
> > > >  wrote:
> > > >> Racket needs *you*. Please.
> > > >> 
> > > >> The proper approach is to have short pages for different language 
> > > >> immigration groups: Python and R come to mind as obvious examples but 
> > > >> I am sure there are others.
> > > >> 
> > > >> What I mean is we need help and *you* can help. Let me explain it with 
> > > >> the Python example:
> > > >> 
> > > >> 1. Set up a page (wiki?) called “From Python to Racket”
> > > >> 
> > > >> 2. Create two sections that are immediately visible from the top:
> > > >> 
> > > >>— idioms
> > > >>— performance pitfalls
> > > >> 
> > > >> 3. In the specific case of Python, the second subsection needs to 
> > > >> start with a subsection on
> > > >> 
> > > >>— Python Lists aren’t Racket Lists
> > > >>— then point to data/ralis and show how to transliterate the 
> > > >> loop/append example like this
> > > >>— optionally also show the more native Racket idiom
> > > >> 
> > > >> 4. When anyone observers another blog/social media/whatever post on 
> > > >> Racket is slow because I come from Python,
> > > >> 
> > > >>(a) point the posters to the page  or
> > > >>(b) if it is a new case, write a section for this example then 
> > > >> do (a)
> > > >> 
> > > >> 
> > > >> If you want to help advertise Racket to others, this is an excellent 
> > > >> way of helping out.
> > > >> 
> > > >> Thanks — Matthias
> > > >> 
> > > >> [[ p.s. For my very first Python program (a couple of days before 
> > > >> meeting with GvR), I used Python’s append and was annoyed beyond 
> > > >> belief. ]]
> > > >> 
> > > >> 
> > > >> --
> > > >> You received this message because you are subscribed to the Google 
> > > >> Groups "Racket Users" group.
> > > >> To unsubscribe from this group and stop receiving emails from it, send 
> > > >> an email to racket-users+unsubscr...@googlegroups.com.
> > > >> For more options, visit https://groups.google.com/d/optout.
> > > > 
> > > > -- 
> > > > You 

Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[David Van Horn]

There are several examples for every function provided by the ralist
library.  (And it's almost verbatim what's in the Racket reference for
pairs and lists.)

But... I can add some early examples.  No problem.

David

On Sat, Feb 16, 2019, 4:00 PM John Clements 
wrote:

> The pointer to RaLists would be much more enticing if we could convince
> David Van Horn to begin his documentation with a couple of small examples….
>
> John
>
> > On Feb 13, 2019, at 14:35, Stephen De Gabrielle 
> wrote:
> >
> > Thanks
> >
> > I should note that anyone with a GitHub account can edit
> https://github.com/racket/racket/wiki/Python-to-Racket
> >
> > S.
> >
> > On Wed, 13 Feb 2019 at 21:26, Matthias Felleisen 
> wrote:
> >
> > Not until there’s demand. I think we do see demand for Python transfers.
> >
> >
> >
> > > On Feb 13, 2019, at 3:11 PM, Stephen De Gabrielle <
> spdegabrie...@gmail.com> wrote:
> > >
> > > Should there be similar pages for Javascript, Java,C#, C/C++, Ruby,
> PHP, Visual Basic, Scratch and Haskell?
> > >
> > > S.
> > >
> > > On Wed, Feb 13, 2019 at 8:03 PM Stephen De Gabrielle <
> spdegabrie...@gmail.com> wrote:
> > > I created a DRAFT page on the Racket GitHub wiki:
> > >   https://github.com/racket/racket/wiki/Python-to-Racket
> > > It links to a 'Choosing a data structure' page
> https://github.com/racket/racket/wiki/Choosing-a-data-structure
> > > - this just as copy of the table created by Jens Axel Søgaard at:
> https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
> )
> > >
> > > Please edit/delete as you see fit
> > >
> > > Kind regards
> > > Stephen
> > >
> > >
> > > On Tue, Feb 12, 2019 at 5:20 PM Matthias Felleisen <
> matth...@felleisen.org> wrote:
> > >
> > > This is perfect! Thanks — Matthias
> > >
> > >
> > >
> > >
> > > > On Feb 11, 2019, at 11:04 PM, Claes Wallin (韋嘉誠) 
> wrote:
> > > >
> > > > For anyone creating such a web page for Python to Racket
> specifically,
> > > > there is probably a great deal of inspiration, and reminders of
> > > > stumbling blocks, to be found in Arne Babenhauserheide's
> > > > https://www.draketo.de/py2guile book (available online for free)
> about
> > > > going from Python to Guile Scheme.
> > > >
> > > > --
> > > >   /c
> > > >
> > > > On Sun, Feb 3, 2019 at 7:00 AM Matthias Felleisen
> > > >  wrote:
> > > >> Racket needs *you*. Please.
> > > >>
> > > >> The proper approach is to have short pages for different language
> immigration groups: Python and R come to mind as obvious examples but I am
> sure there are others.
> > > >>
> > > >> What I mean is we need help and *you* can help. Let me explain it
> with the Python example:
> > > >>
> > > >> 1. Set up a page (wiki?) called “From Python to Racket”
> > > >>
> > > >> 2. Create two sections that are immediately visible from the top:
> > > >>
> > > >>— idioms
> > > >>— performance pitfalls
> > > >>
> > > >> 3. In the specific case of Python, the second subsection needs to
> start with a subsection on
> > > >>
> > > >>— Python Lists aren’t Racket Lists
> > > >>— then point to data/ralis and show how to transliterate the
> loop/append example like this
> > > >>— optionally also show the more native Racket idiom
> > > >>
> > > >> 4. When anyone observers another blog/social media/whatever post on
> Racket is slow because I come from Python,
> > > >>
> > > >>(a) point the posters to the page  or
> > > >>(b) if it is a new case, write a section for this example
> then do (a)
> > > >>
> > > >>
> > > >> If you want to help advertise Racket to others, this is an
> excellent way of helping out.
> > > >>
> > > >> Thanks — Matthias
> > > >>
> > > >> [[ p.s. For my very first Python program (a couple of days before
> meeting with GvR), I used Python’s append and was annoyed beyond belief. ]]
> > > >>
> > > >>
> > > >> --
> > > >> You received this message because you are subscribed to the Google
> Groups "Racket Users" group.
> > > >> To unsubscribe from this group and stop receiving emails from it,
> send an email to racket-users+unsubscr...@googlegroups.com.
> > > >> For more options, visit https://groups.google.com/d/optout.
> > > >
> > > > --
> > > > You received this message because you are subscribed to the Google
> Groups "Racket Users" group.
> > > > To unsubscribe from this group and stop receiving emails from it,
> send an email to racket-users+unsubscr...@googlegroups.com.
> > > > For more options, visit https://groups.google.com/d/optout.
> > >
> > > --
> > > You received this message because you are subscribed to the Google
> Groups "Racket Users" group.
> > > To unsubscribe from this group and stop receiving emails from it, send
> an email to racket-users+unsubscr...@googlegroups.com.
> > > For more options, visit https://groups.google.com/d/optout.
> >
> > --
> > 
> >
> > --
> > You received this message because you are subscribed to the Google
> Groups "Racket Users" group.

Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

['John Clements' via Racket Users]

The pointer to RaLists would be much more enticing if we could convince David 
Van Horn to begin his documentation with a couple of small examples…. 

John

> On Feb 13, 2019, at 14:35, Stephen De Gabrielle  
> wrote:
> 
> Thanks 
> 
> I should note that anyone with a GitHub account can edit 
> https://github.com/racket/racket/wiki/Python-to-Racket
> 
> S.
> 
> On Wed, 13 Feb 2019 at 21:26, Matthias Felleisen  
> wrote:
> 
> Not until there’s demand. I think we do see demand for Python transfers. 
> 
> 
> 
> > On Feb 13, 2019, at 3:11 PM, Stephen De Gabrielle  
> > wrote:
> > 
> > Should there be similar pages for Javascript, Java,C#, C/C++, Ruby, PHP, 
> > Visual Basic, Scratch and Haskell?
> > 
> > S.
> > 
> > On Wed, Feb 13, 2019 at 8:03 PM Stephen De Gabrielle 
> >  wrote:
> > I created a DRAFT page on the Racket GitHub wiki:
> >   https://github.com/racket/racket/wiki/Python-to-Racket
> > It links to a 'Choosing a data structure' page 
> > https://github.com/racket/racket/wiki/Choosing-a-data-structure
> > - this just as copy of the table created by Jens Axel Søgaard at: 
> > https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146)
> > 
> > Please edit/delete as you see fit
> > 
> > Kind regards
> > Stephen
> > 
> > 
> > On Tue, Feb 12, 2019 at 5:20 PM Matthias Felleisen  
> > wrote:
> > 
> > This is perfect! Thanks — Matthias
> > 
> > 
> > 
> > 
> > > On Feb 11, 2019, at 11:04 PM, Claes Wallin (韋嘉誠)  wrote:
> > > 
> > > For anyone creating such a web page for Python to Racket specifically,
> > > there is probably a great deal of inspiration, and reminders of
> > > stumbling blocks, to be found in Arne Babenhauserheide's
> > > https://www.draketo.de/py2guile book (available online for free) about
> > > going from Python to Guile Scheme.
> > > 
> > > -- 
> > >   /c
> > > 
> > > On Sun, Feb 3, 2019 at 7:00 AM Matthias Felleisen
> > >  wrote:
> > >> Racket needs *you*. Please.
> > >> 
> > >> The proper approach is to have short pages for different language 
> > >> immigration groups: Python and R come to mind as obvious examples but I 
> > >> am sure there are others.
> > >> 
> > >> What I mean is we need help and *you* can help. Let me explain it with 
> > >> the Python example:
> > >> 
> > >> 1. Set up a page (wiki?) called “From Python to Racket”
> > >> 
> > >> 2. Create two sections that are immediately visible from the top:
> > >> 
> > >>— idioms
> > >>— performance pitfalls
> > >> 
> > >> 3. In the specific case of Python, the second subsection needs to start 
> > >> with a subsection on
> > >> 
> > >>— Python Lists aren’t Racket Lists
> > >>— then point to data/ralis and show how to transliterate the 
> > >> loop/append example like this
> > >>— optionally also show the more native Racket idiom
> > >> 
> > >> 4. When anyone observers another blog/social media/whatever post on 
> > >> Racket is slow because I come from Python,
> > >> 
> > >>(a) point the posters to the page  or
> > >>(b) if it is a new case, write a section for this example then do 
> > >> (a)
> > >> 
> > >> 
> > >> If you want to help advertise Racket to others, this is an excellent way 
> > >> of helping out.
> > >> 
> > >> Thanks — Matthias
> > >> 
> > >> [[ p.s. For my very first Python program (a couple of days before 
> > >> meeting with GvR), I used Python’s append and was annoyed beyond belief. 
> > >> ]]
> > >> 
> > >> 
> > >> --
> > >> You received this message because you are subscribed to the Google 
> > >> Groups "Racket Users" group.
> > >> To unsubscribe from this group and stop receiving emails from it, send 
> > >> an email to racket-users+unsubscr...@googlegroups.com.
> > >> For more options, visit https://groups.google.com/d/optout.
> > > 
> > > -- 
> > > You received this message because you are subscribed to the Google Groups 
> > > "Racket Users" group.
> > > To unsubscribe from this group and stop receiving emails from it, send an 
> > > email to racket-users+unsubscr...@googlegroups.com.
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> > 
> > -- 
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> > "Racket Users" group.
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> > email to racket-users+unsubscr...@googlegroups.com.
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> 
> -- 
> 
> 
> -- 
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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Stephen De Gabrielle]

Thanks

I should note that anyone with a GitHub account can edit
https://github.com/racket/racket/wiki/Python-to-Racket

S.

On Wed, 13 Feb 2019 at 21:26, Matthias Felleisen 
wrote:

>
> Not until there’s demand. I think we do see demand for Python transfers.
>
>
>
> > On Feb 13, 2019, at 3:11 PM, Stephen De Gabrielle <
> spdegabrie...@gmail.com> wrote:
> >
> > Should there be similar pages for Javascript, Java,C#, C/C++, Ruby, PHP,
> Visual Basic, Scratch and Haskell?
> >
> > S.
> >
> > On Wed, Feb 13, 2019 at 8:03 PM Stephen De Gabrielle <
> spdegabrie...@gmail.com> wrote:
> > I created a DRAFT page on the Racket GitHub wiki:
> >   https://github.com/racket/racket/wiki/Python-to-Racket
> > It links to a 'Choosing a data structure' page
> https://github.com/racket/racket/wiki/Choosing-a-data-structure
> > - this just as copy of the table created by Jens Axel Søgaard at:
> https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
> )
> >
> > Please edit/delete as you see fit
> >
> > Kind regards
> > Stephen
> >
> >
> > On Tue, Feb 12, 2019 at 5:20 PM Matthias Felleisen <
> matth...@felleisen.org> wrote:
> >
> > This is perfect! Thanks — Matthias
> >
> >
> >
> >
> > > On Feb 11, 2019, at 11:04 PM, Claes Wallin (韋嘉誠) 
> wrote:
> > >
> > > For anyone creating such a web page for Python to Racket specifically,
> > > there is probably a great deal of inspiration, and reminders of
> > > stumbling blocks, to be found in Arne Babenhauserheide's
> > > https://www.draketo.de/py2guile book (available online for free) about
> > > going from Python to Guile Scheme.
> > >
> > > --
> > >   /c
> > >
> > > On Sun, Feb 3, 2019 at 7:00 AM Matthias Felleisen
> > >  wrote:
> > >> Racket needs *you*. Please.
> > >>
> > >> The proper approach is to have short pages for different language
> immigration groups: Python and R come to mind as obvious examples but I am
> sure there are others.
> > >>
> > >> What I mean is we need help and *you* can help. Let me explain it
> with the Python example:
> > >>
> > >> 1. Set up a page (wiki?) called “From Python to Racket”
> > >>
> > >> 2. Create two sections that are immediately visible from the top:
> > >>
> > >>— idioms
> > >>— performance pitfalls
> > >>
> > >> 3. In the specific case of Python, the second subsection needs to
> start with a subsection on
> > >>
> > >>— Python Lists aren’t Racket Lists
> > >>— then point to data/ralis and show how to transliterate the
> loop/append example like this
> > >>— optionally also show the more native Racket idiom
> > >>
> > >> 4. When anyone observers another blog/social media/whatever post on
> Racket is slow because I come from Python,
> > >>
> > >>(a) point the posters to the page  or
> > >>(b) if it is a new case, write a section for this example then
> do (a)
> > >>
> > >>
> > >> If you want to help advertise Racket to others, this is an excellent
> way of helping out.
> > >>
> > >> Thanks — Matthias
> > >>
> > >> [[ p.s. For my very first Python program (a couple of days before
> meeting with GvR), I used Python’s append and was annoyed beyond belief. ]]
> > >>
> > >>
> > >> --
> > >> You received this message because you are subscribed to the Google
> Groups "Racket Users" group.
> > >> To unsubscribe from this group and stop receiving emails from it,
> send an email to racket-users+unsubscr...@googlegroups.com.
> > >> For more options, visit https://groups.google.com/d/optout.
> > >
> > > --
> > > You received this message because you are subscribed to the Google
> Groups "Racket Users" group.
> > > To unsubscribe from this group and stop receiving emails from it, send
> an email to racket-users+unsubscr...@googlegroups.com.
> > > For more options, visit https://groups.google.com/d/optout.
> >
> > --
> > You received this message because you are subscribed to the Google
> Groups "Racket Users" group.
> > To unsubscribe from this group and stop receiving emails from it, send
> an email to racket-users+unsubscr...@googlegroups.com.
> > For more options, visit https://groups.google.com/d/optout.
>
> --


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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Stephen De Gabrielle]

Should there be similar pages for Javascript, Java,C#, C/C++, Ruby, PHP,
Visual Basic, Scratch and Haskell?

S.

On Wed, Feb 13, 2019 at 8:03 PM Stephen De Gabrielle <
spdegabrie...@gmail.com> wrote:

> I created a DRAFT page on the Racket GitHub wiki:
>   https://github.com/racket/racket/wiki/Python-to-Racket
> It links to a 'Choosing a data structure' page
> https://github.com/racket/racket/wiki/Choosing-a-data-structure
> - this just as copy of the table created by Jens Axel Søgaard at:
> https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
> )
>
> Please edit/delete as you see fit
>
> Kind regards
> Stephen
>
>
> On Tue, Feb 12, 2019 at 5:20 PM Matthias Felleisen 
> wrote:
>
>>
>> This is perfect! Thanks — Matthias
>>
>>
>>
>>
>> > On Feb 11, 2019, at 11:04 PM, Claes Wallin (韋嘉誠) 
>> wrote:
>> >
>> > For anyone creating such a web page for Python to Racket specifically,
>> > there is probably a great deal of inspiration, and reminders of
>> > stumbling blocks, to be found in Arne Babenhauserheide's
>> > https://www.draketo.de/py2guile book (available online for free) about
>> > going from Python to Guile Scheme.
>> >
>> > --
>> >   /c
>> >
>> > On Sun, Feb 3, 2019 at 7:00 AM Matthias Felleisen
>> >  wrote:
>> >> Racket needs *you*. Please.
>> >>
>> >> The proper approach is to have short pages for different language
>> immigration groups: Python and R come to mind as obvious examples but I am
>> sure there are others.
>> >>
>> >> What I mean is we need help and *you* can help. Let me explain it with
>> the Python example:
>> >>
>> >> 1. Set up a page (wiki?) called “From Python to Racket”
>> >>
>> >> 2. Create two sections that are immediately visible from the top:
>> >>
>> >>— idioms
>> >>— performance pitfalls
>> >>
>> >> 3. In the specific case of Python, the second subsection needs to
>> start with a subsection on
>> >>
>> >>— Python Lists aren’t Racket Lists
>> >>— then point to data/ralis and show how to transliterate the
>> loop/append example like this
>> >>— optionally also show the more native Racket idiom
>> >>
>> >> 4. When anyone observers another blog/social media/whatever post on
>> Racket is slow because I come from Python,
>> >>
>> >>(a) point the posters to the page  or
>> >>(b) if it is a new case, write a section for this example then
>> do (a)
>> >>
>> >>
>> >> If you want to help advertise Racket to others, this is an excellent
>> way of helping out.
>> >>
>> >> Thanks — Matthias
>> >>
>> >> [[ p.s. For my very first Python program (a couple of days before
>> meeting with GvR), I used Python’s append and was annoyed beyond belief. ]]
>> >>
>> >>
>> >> --
>> >> You received this message because you are subscribed to the Google
>> Groups "Racket Users" group.
>> >> To unsubscribe from this group and stop receiving emails from it, send
>> an email to racket-users+unsubscr...@googlegroups.com.
>> >> For more options, visit https://groups.google.com/d/optout.
>> >
>> > --
>> > You received this message because you are subscribed to the Google
>> Groups "Racket Users" group.
>> > To unsubscribe from this group and stop receiving emails from it, send
>> an email to racket-users+unsubscr...@googlegroups.com.
>> > For more options, visit https://groups.google.com/d/optout.
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "Racket Users" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to racket-users+unsubscr...@googlegroups.com.
>> For more options, visit https://groups.google.com/d/optout.
>>
>

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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Stephen De Gabrielle]

I created a DRAFT page on the Racket GitHub wiki:
  https://github.com/racket/racket/wiki/Python-to-Racket
It links to a 'Choosing a data structure' page
https://github.com/racket/racket/wiki/Choosing-a-data-structure
- this just as copy of the table created by Jens Axel Søgaard at:
https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
)

Please edit/delete as you see fit

Kind regards
Stephen


On Tue, Feb 12, 2019 at 5:20 PM Matthias Felleisen 
wrote:

>
> This is perfect! Thanks — Matthias
>
>
>
>
> > On Feb 11, 2019, at 11:04 PM, Claes Wallin (韋嘉誠) 
> wrote:
> >
> > For anyone creating such a web page for Python to Racket specifically,
> > there is probably a great deal of inspiration, and reminders of
> > stumbling blocks, to be found in Arne Babenhauserheide's
> > https://www.draketo.de/py2guile book (available online for free) about
> > going from Python to Guile Scheme.
> >
> > --
> >   /c
> >
> > On Sun, Feb 3, 2019 at 7:00 AM Matthias Felleisen
> >  wrote:
> >> Racket needs *you*. Please.
> >>
> >> The proper approach is to have short pages for different language
> immigration groups: Python and R come to mind as obvious examples but I am
> sure there are others.
> >>
> >> What I mean is we need help and *you* can help. Let me explain it with
> the Python example:
> >>
> >> 1. Set up a page (wiki?) called “From Python to Racket”
> >>
> >> 2. Create two sections that are immediately visible from the top:
> >>
> >>— idioms
> >>— performance pitfalls
> >>
> >> 3. In the specific case of Python, the second subsection needs to start
> with a subsection on
> >>
> >>— Python Lists aren’t Racket Lists
> >>— then point to data/ralis and show how to transliterate the
> loop/append example like this
> >>— optionally also show the more native Racket idiom
> >>
> >> 4. When anyone observers another blog/social media/whatever post on
> Racket is slow because I come from Python,
> >>
> >>(a) point the posters to the page  or
> >>(b) if it is a new case, write a section for this example then
> do (a)
> >>
> >>
> >> If you want to help advertise Racket to others, this is an excellent
> way of helping out.
> >>
> >> Thanks — Matthias
> >>
> >> [[ p.s. For my very first Python program (a couple of days before
> meeting with GvR), I used Python’s append and was annoyed beyond belief. ]]
> >>
> >>
> >> --
> >> You received this message because you are subscribed to the Google
> Groups "Racket Users" group.
> >> To unsubscribe from this group and stop receiving emails from it, send
> an email to racket-users+unsubscr...@googlegroups.com.
> >> For more options, visit https://groups.google.com/d/optout.
> >
> > --
> > You received this message because you are subscribed to the Google
> Groups "Racket Users" group.
> > To unsubscribe from this group and stop receiving emails from it, send
> an email to racket-users+unsubscr...@googlegroups.com.
> > For more options, visit https://groups.google.com/d/optout.
>
> --
> You received this message because you are subscribed to the Google Groups
> "Racket Users" group.
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> email to racket-users+unsubscr...@googlegroups.com.
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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[韋嘉誠]

For anyone creating such a web page for Python to Racket specifically,
there is probably a great deal of inspiration, and reminders of
stumbling blocks, to be found in Arne Babenhauserheide's
https://www.draketo.de/py2guile book (available online for free) about
going from Python to Guile Scheme.

-- 
   /c

On Sun, Feb 3, 2019 at 7:00 AM Matthias Felleisen
 wrote:
> Racket needs *you*. Please.
>
> The proper approach is to have short pages for different language immigration 
> groups: Python and R come to mind as obvious examples but I am sure there are 
> others.
>
> What I mean is we need help and *you* can help. Let me explain it with the 
> Python example:
>
> 1. Set up a page (wiki?) called “From Python to Racket”
>
> 2. Create two sections that are immediately visible from the top:
>
> — idioms
> — performance pitfalls
>
> 3. In the specific case of Python, the second subsection needs to start with 
> a subsection on
>
> — Python Lists aren’t Racket Lists
> — then point to data/ralis and show how to transliterate the 
> loop/append example like this
> — optionally also show the more native Racket idiom
>
> 4. When anyone observers another blog/social media/whatever post on Racket is 
> slow because I come from Python,
>
> (a) point the posters to the page  or
> (b) if it is a new case, write a section for this example then do (a)
>
>
> If you want to help advertise Racket to others, this is an excellent way of 
> helping out.
>
> Thanks — Matthias
>
> [[ p.s. For my very first Python program (a couple of days before meeting 
> with GvR), I used Python’s append and was annoyed beyond belief. ]]
>
>
> --
> You received this message because you are subscribed to the Google Groups 
> "Racket Users" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to racket-users+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.

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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Matthias Felleisen]

Great. Let’s include this link in Alex’s write up as an example of a concrete 
comparison. Even if such simple benchmarks don’t reflect daily, end-to-end 
programs, they can help people by dispelling some prejudices. Thanks — Matthias



> On Feb 4, 2019, at 11:56 AM, Gustavo Massaccesi  wrote:
> 
> For some reason, the Racket vs Python performance is a question that arise 
> from time to time in Hacke News (like 2 or 3 times per year). Last time I 
> asked if it was possible to add a direct comparison in The Computer Language 
> Benchmarks Game and the owner/maintainer added that page. The results are in 
> https://benchmarksgame-team.pages.debian.net/benchmarksgame/faster/racket-python3.html
>  [Standard disclaimer: The results change from program to program, so take 
> this comparison only as a guide.]
> 
> A short version of the results is that:
> * in 6 of the programs Racket is much faster
> * in 1 of the programs Racket is faster
> * in 2 of the programs there is almost a tie
> * in 1 of the programs Racket is slower
> 
> Some programs in Racket need parallelization, so the results may improve in 
> the future. [I didn't look too carefully at the programs in Python.]
> 
> My unofficial takeaway, not completely backed by the benchmarks, is that
> * For numeric programs Racket is (may be) 5 to 20 times faster than Python
> * For programs with too many stings and hashes, the speed is almost the same.
> 
> 
> 
> Also, there was an old thread about translating the classic Norvig's spelling 
> correction from Python to Racket, without changing the structure of the 
> implementation too much and using idiomatic code.
> https://groups.google.com/forum/#!topic/racket-users/u0Ua1kTUSKw After a few 
> attempts, the final version in Racket was a 30% slower. I didn't follow this 
> too much after the discussion, so I don't know if there is a smaller or 
> bigger difference using the current versions. (Also, I think we never tried 
> to make is fast as possible, with the same algorithms, but changing the 
> implementation as much as it was necessary.)
> 
> Gustavo
> 
> On Sun, Feb 3, 2019 at 7:38 PM Matthias Felleisen  
> wrote:
> 
> Agreed! 
> 
> 
> 
>> On Feb 3, 2019, at 4:43 PM, Robby Findler  
>> wrote:
>> 
>> It seems like a great addition to the performance section of the guide. 
>> 
>> Robby 
>> 
>> On Sun, Feb 3, 2019 at 3:35 PM Matthias Felleisen  
>> wrote:
>> 
>> 1. I think this is a great start for a generic introduction to data 
>> structures. Someone should integrate Jens’s short table: 
>> 
>>  
>> https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
>>  
>> 
>> 
>> 2. I think language-to-language documents serve a different role, but your 
>> document could be cited from there. 
>> 
>> The point of say “From Python to Racket” would be to show how comprehensions 
>> translate or how classes work 1-1. And yes, it would also explain that 
>> Racket calls something a list that does __not___ at all correspond to a 
>> list. 
>> 
>> The corresponding Java write-up would be quite different again. In that 
>> case, we would be dealing with people who might not know more than classes 
>> and methods. But they might actually know proper design and might know that 
>> it calls for recursion (hidden in classes and interfaces). In Racket, that 
>> works even better than in Java. Plus it would need to say something brief 
>> about types. 
>> 
>> And R would be an entirely different story. 
>> 
>> — Matthias
>> 
>> 
>> 
>> 
>> 
>>> On Feb 2, 2019, at 11:37 PM, Alex Harsanyi  wrote:
>>> 
>>> 
>>> I put together some notes about available data structures in Racket, with 
>>> some performance considerations.  It needs more work, but perhaps it can be 
>>> used as a starting point and it can be added to the Racket wiki, if/when 
>>> others consider it adequate:
>>> 
>>> https://gist.github.com/alex-hhh/3cc5690a7f9c74543dab6c11344e6202
>>> 
>>> I didn't write a "Python to Racket" guide, because I don't really know 
>>> enough about Python to write such a document, and I also think that a more 
>>> generic document is simpler to maintain and can be used by people who come 
>>> from other languages as well.
>>> 
>>> I also tried to keep the document short, the aim being to provide a 
>>> competent programmer who is new to Racket with a 5 minute overview to its 
>>> data structures and some links to the starting points in the documentation. 
>>>  We can add things to it, but I think it is better to keep it short rather 
>>> than comprehensive in this case -- after all, there is the Racket Guide and 
>>> Racket Reference and these documents contain all the details.  Perhaps new 
>>> documents can be added to the wiki, exploring other topics in more detail.
>>> 
>>> I did not mention `ralist` because (1) I have no experience with it, but 
>>> more importantly (2) the package is not part of the Racket distribution and 
>>> has to be installed separately.  I 

Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Gustavo Massaccesi]

For some reason, the Racket vs Python performance is a question that arise
from time to time in Hacke News (like 2 or 3 times per year). Last time I
asked if it was possible to add a direct comparison in The Computer
Language Benchmarks Game and the owner/maintainer added that page. The
results are in
https://benchmarksgame-team.pages.debian.net/benchmarksgame/faster/racket-python3.html
[Standard disclaimer: The results change from program to program, so take
this comparison only as a guide.]

A short version of the results is that:
* in 6 of the programs Racket is much faster
* in 1 of the programs Racket is faster
* in 2 of the programs there is almost a tie
* in 1 of the programs Racket is slower

Some programs in Racket need parallelization, so the results may improve in
the future. [I didn't look too carefully at the programs in Python.]

My unofficial takeaway, not completely backed by the benchmarks, is that
* For numeric programs Racket is (may be) 5 to 20 times faster than Python
* For programs with too many stings and hashes, the speed is almost the
same.



Also, there was an old thread about translating the classic Norvig's
spelling correction from Python to Racket, without changing the structure
of the implementation too much and using idiomatic code.
https://groups.google.com/forum/#!topic/racket-users/u0Ua1kTUSKw After a
few attempts, the final version in Racket was a 30% slower. I didn't follow
this too much after the discussion, so I don't know if there is a smaller
or bigger difference using the current versions. (Also, I think we never
tried to make is fast as possible, with the same algorithms, but changing
the implementation as much as it was necessary.)

Gustavo

On Sun, Feb 3, 2019 at 7:38 PM Matthias Felleisen 
wrote:

>
> Agreed!
>
>
>
> On Feb 3, 2019, at 4:43 PM, Robby Findler 
> wrote:
>
> It seems like a great addition to the performance section of the guide.
>
> Robby
>
> On Sun, Feb 3, 2019 at 3:35 PM Matthias Felleisen 
> wrote:
>
>>
>> 1. I think this is a great start for a generic introduction to data
>> structures. Someone should integrate Jens’s short table:
>>
>>
>> https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
>>
>>
>>
>> 2. I think language-to-language documents serve a different role, but
>> your document could be cited from there.
>>
>> The point of say “From Python to Racket” would be to show how
>> comprehensions translate or how classes work 1-1. And yes, it would also
>> explain that Racket calls something a list that does __not___ at all
>> correspond to a list.
>>
>> The corresponding Java write-up would be quite different again. In that
>> case, we would be dealing with people who might not know more than classes
>> and methods. But they might actually know proper design and might know that
>> it calls for recursion (hidden in classes and interfaces). In Racket, that
>> works even better than in Java. Plus it would need to say something brief
>> about types.
>>
>> And R would be an entirely different story.
>>
>> — Matthias
>>
>>
>>
>>
>>
>> On Feb 2, 2019, at 11:37 PM, Alex Harsanyi 
>> wrote:
>>
>>
>> I put together some notes about available data structures in Racket, with
>> some performance considerations.  It needs more work, but perhaps it can be
>> used as a starting point and it can be added to the Racket wiki, if/when
>> others consider it adequate:
>>
>> https://gist.github.com/alex-hhh/3cc5690a7f9c74543dab6c11344e6202
>>
>> I didn't write a "Python to Racket" guide, because I don't really know
>> enough about Python to write such a document, and I also think that a more
>> generic document is simpler to maintain and can be used by people who come
>> from other languages as well.
>>
>> I also tried to keep the document short, the aim being to provide a
>> competent programmer who is new to Racket with a 5 minute overview to its
>> data structures and some links to the starting points in the
>> documentation.  We can add things to it, but I think it is better to keep
>> it short rather than comprehensive in this case -- after all, there is the
>> Racket Guide and Racket Reference and these documents contain all the
>> details.  Perhaps new documents can be added to the wiki, exploring other
>> topics in more detail.
>>
>> I did not mention `ralist` because (1) I have no experience with it, but
>> more importantly (2) the package is not part of the Racket distribution and
>> has to be installed separately.  I don't it reflects well on Racket if we
>> tell people to install a separate package if they want an efficient
>> container...  I have no experience with `ralist`, but if it is indeed a
>> good data structure and it has a potentially wide usage, it should be
>> included in the default Racket installation.
>>
>> Alex.
>>
>> On Sunday, February 3, 2019 at 7:00:10 AM UTC+8, Matthias Felleisen wrote:
>>>
>>>
>>>
>>> Racket needs *you*. Please.
>>>
>>> The proper approach is to 

Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Matthias Felleisen]

Agreed! 



> On Feb 3, 2019, at 4:43 PM, Robby Findler  wrote:
> 
> It seems like a great addition to the performance section of the guide. 
> 
> Robby 
> 
> On Sun, Feb 3, 2019 at 3:35 PM Matthias Felleisen  > wrote:
> 
> 1. I think this is a great start for a generic introduction to data 
> structures. Someone should integrate Jens’s short table: 
> 
>  
> https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
>  
> 
>  
> 
> 
> 2. I think language-to-language documents serve a different role, but your 
> document could be cited from there. 
> 
> The point of say “From Python to Racket” would be to show how comprehensions 
> translate or how classes work 1-1. And yes, it would also explain that Racket 
> calls something a list that does __not___ at all correspond to a list. 
> 
> The corresponding Java write-up would be quite different again. In that case, 
> we would be dealing with people who might not know more than classes and 
> methods. But they might actually know proper design and might know that it 
> calls for recursion (hidden in classes and interfaces). In Racket, that works 
> even better than in Java. Plus it would need to say something brief about 
> types. 
> 
> And R would be an entirely different story. 
> 
> — Matthias
> 
> 
> 
> 
> 
>> On Feb 2, 2019, at 11:37 PM, Alex Harsanyi > > wrote:
>> 
>> 
>> I put together some notes about available data structures in Racket, with 
>> some performance considerations.  It needs more work, but perhaps it can be 
>> used as a starting point and it can be added to the Racket wiki, if/when 
>> others consider it adequate:
>> 
>> https://gist.github.com/alex-hhh/3cc5690a7f9c74543dab6c11344e6202 
>> 
>> 
>> I didn't write a "Python to Racket" guide, because I don't really know 
>> enough about Python to write such a document, and I also think that a more 
>> generic document is simpler to maintain and can be used by people who come 
>> from other languages as well.
>> 
>> I also tried to keep the document short, the aim being to provide a 
>> competent programmer who is new to Racket with a 5 minute overview to its 
>> data structures and some links to the starting points in the documentation.  
>> We can add things to it, but I think it is better to keep it short rather 
>> than comprehensive in this case -- after all, there is the Racket Guide and 
>> Racket Reference and these documents contain all the details.  Perhaps new 
>> documents can be added to the wiki, exploring other topics in more detail.
>> 
>> I did not mention `ralist` because (1) I have no experience with it, but 
>> more importantly (2) the package is not part of the Racket distribution and 
>> has to be installed separately.  I don't it reflects well on Racket if we 
>> tell people to install a separate package if they want an efficient 
>> container...  I have no experience with `ralist`, but if it is indeed a good 
>> data structure and it has a potentially wide usage, it should be included in 
>> the default Racket installation.
>> 
>> Alex.
>> 
>> On Sunday, February 3, 2019 at 7:00:10 AM UTC+8, Matthias Felleisen wrote:
>> 
>> 
>> Racket needs *you*. Please. 
>> 
>> The proper approach is to have short pages for different language 
>> immigration groups: Python and R come to mind as obvious examples but I am 
>> sure there are others. 
>> 
>> What I mean is we need help and *you* can help. Let me explain it with the 
>> Python example: 
>> 
>> 1. Set up a page (wiki?) called “From Python to Racket” 
>> 
>> 2. Create two sections that are immediately visible from the top: 
>>  
>> — idioms 
>> — performance pitfalls 
>> 
>> 3. In the specific case of Python, the second subsection needs to start with 
>> a subsection on 
>> 
>> — Python Lists aren’t Racket Lists 
>> — then point to data/ralis and show how to transliterate the 
>> loop/append example like this 
>> — optionally also show the more native Racket idiom 
>> 
>> 4. When anyone observers another blog/social media/whatever post on Racket 
>> is slow because I come from Python, 
>> 
>> (a) point the posters to the page  or 
>> (b) if it is a new case, write a section for this example then do 
>> (a) 
>> 
>> 
>> If you want to help advertise Racket to others, this is an excellent way of 
>> helping out. 
>> 
>> Thanks — Matthias 
>> 
>> [[ p.s. For my very first Python program (a couple of days before meeting 
>> with GvR), I used Python’s append and was annoyed beyond belief. ]] 
>> 
>> 
>> 
>> -- 
>> You received this message because you are subscribed to the Google Groups 
>> "Racket Users" group.
>> To unsubscribe from this group and stop 

Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Robby Findler]

It seems like a great addition to the performance section of the guide.

Robby

On Sun, Feb 3, 2019 at 3:35 PM Matthias Felleisen 
wrote:

>
> 1. I think this is a great start for a generic introduction to data
> structures. Someone should integrate Jens’s short table:
>
>
> https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
>
>
>
> 2. I think language-to-language documents serve a different role, but your
> document could be cited from there.
>
> The point of say “From Python to Racket” would be to show how
> comprehensions translate or how classes work 1-1. And yes, it would also
> explain that Racket calls something a list that does __not___ at all
> correspond to a list.
>
> The corresponding Java write-up would be quite different again. In that
> case, we would be dealing with people who might not know more than classes
> and methods. But they might actually know proper design and might know that
> it calls for recursion (hidden in classes and interfaces). In Racket, that
> works even better than in Java. Plus it would need to say something brief
> about types.
>
> And R would be an entirely different story.
>
> — Matthias
>
>
>
>
>
> On Feb 2, 2019, at 11:37 PM, Alex Harsanyi  wrote:
>
>
> I put together some notes about available data structures in Racket, with
> some performance considerations.  It needs more work, but perhaps it can be
> used as a starting point and it can be added to the Racket wiki, if/when
> others consider it adequate:
>
> https://gist.github.com/alex-hhh/3cc5690a7f9c74543dab6c11344e6202
>
> I didn't write a "Python to Racket" guide, because I don't really know
> enough about Python to write such a document, and I also think that a more
> generic document is simpler to maintain and can be used by people who come
> from other languages as well.
>
> I also tried to keep the document short, the aim being to provide a
> competent programmer who is new to Racket with a 5 minute overview to its
> data structures and some links to the starting points in the
> documentation.  We can add things to it, but I think it is better to keep
> it short rather than comprehensive in this case -- after all, there is the
> Racket Guide and Racket Reference and these documents contain all the
> details.  Perhaps new documents can be added to the wiki, exploring other
> topics in more detail.
>
> I did not mention `ralist` because (1) I have no experience with it, but
> more importantly (2) the package is not part of the Racket distribution and
> has to be installed separately.  I don't it reflects well on Racket if we
> tell people to install a separate package if they want an efficient
> container...  I have no experience with `ralist`, but if it is indeed a
> good data structure and it has a potentially wide usage, it should be
> included in the default Racket installation.
>
> Alex.
>
> On Sunday, February 3, 2019 at 7:00:10 AM UTC+8, Matthias Felleisen wrote:
>>
>>
>>
>> Racket needs *you*. Please.
>>
>> The proper approach is to have short pages for different language
>> immigration groups: Python and R come to mind as obvious examples but I am
>> sure there are others.
>>
>> What I mean is we need help and *you* can help. Let me explain it with
>> the Python example:
>>
>> 1. Set up a page (wiki?) called “From Python to Racket”
>>
>> 2. Create two sections that are immediately visible from the top:
>>
>> — idioms
>> — performance pitfalls
>>
>> 3. In the specific case of Python, the second subsection needs to start
>> with a subsection on
>>
>> — Python Lists aren’t Racket Lists
>> — then point to data/ralis and show how to transliterate the
>> loop/append example like this
>> — optionally also show the more native Racket idiom
>>
>> 4. When anyone observers another blog/social media/whatever post on
>> Racket is slow because I come from Python,
>>
>> (a) point the posters to the page  or
>> (b) if it is a new case, write a section for this example then do
>> (a)
>>
>>
>> If you want to help advertise Racket to others, this is an excellent way
>> of helping out.
>>
>> Thanks — Matthias
>>
>> [[ p.s. For my very first Python program (a couple of days before meeting
>> with GvR), I used Python’s append and was annoyed beyond belief. ]]
>>
>>
>>
> --
> You received this message because you are subscribed to the Google Groups
> "Racket Users" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to racket-users+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>
>
> --
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> "Racket Users" group.
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> email to racket-users+unsubscr...@googlegroups.com.
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>

-- 
You received this message because 

Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Matthias Felleisen]

1. I think this is a great start for a generic introduction to data structures. 
Someone should integrate Jens’s short table: 

 
https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146
 

 


2. I think language-to-language documents serve a different role, but your 
document could be cited from there. 

The point of say “From Python to Racket” would be to show how comprehensions 
translate or how classes work 1-1. And yes, it would also explain that Racket 
calls something a list that does __not___ at all correspond to a list. 

The corresponding Java write-up would be quite different again. In that case, 
we would be dealing with people who might not know more than classes and 
methods. But they might actually know proper design and might know that it 
calls for recursion (hidden in classes and interfaces). In Racket, that works 
even better than in Java. Plus it would need to say something brief about 
types. 

And R would be an entirely different story. 

— Matthias





> On Feb 2, 2019, at 11:37 PM, Alex Harsanyi  wrote:
> 
> 
> I put together some notes about available data structures in Racket, with 
> some performance considerations.  It needs more work, but perhaps it can be 
> used as a starting point and it can be added to the Racket wiki, if/when 
> others consider it adequate:
> 
> https://gist.github.com/alex-hhh/3cc5690a7f9c74543dab6c11344e6202
> 
> I didn't write a "Python to Racket" guide, because I don't really know enough 
> about Python to write such a document, and I also think that a more generic 
> document is simpler to maintain and can be used by people who come from other 
> languages as well.
> 
> I also tried to keep the document short, the aim being to provide a competent 
> programmer who is new to Racket with a 5 minute overview to its data 
> structures and some links to the starting points in the documentation.  We 
> can add things to it, but I think it is better to keep it short rather than 
> comprehensive in this case -- after all, there is the Racket Guide and Racket 
> Reference and these documents contain all the details.  Perhaps new documents 
> can be added to the wiki, exploring other topics in more detail.
> 
> I did not mention `ralist` because (1) I have no experience with it, but more 
> importantly (2) the package is not part of the Racket distribution and has to 
> be installed separately.  I don't it reflects well on Racket if we tell 
> people to install a separate package if they want an efficient container...  
> I have no experience with `ralist`, but if it is indeed a good data structure 
> and it has a potentially wide usage, it should be included in the default 
> Racket installation.
> 
> Alex.
> 
> On Sunday, February 3, 2019 at 7:00:10 AM UTC+8, Matthias Felleisen wrote:
> 
> 
> Racket needs *you*. Please. 
> 
> The proper approach is to have short pages for different language immigration 
> groups: Python and R come to mind as obvious examples but I am sure there are 
> others. 
> 
> What I mean is we need help and *you* can help. Let me explain it with the 
> Python example: 
> 
> 1. Set up a page (wiki?) called “From Python to Racket” 
> 
> 2. Create two sections that are immediately visible from the top: 
>  
> — idioms 
> — performance pitfalls 
> 
> 3. In the specific case of Python, the second subsection needs to start with 
> a subsection on 
> 
> — Python Lists aren’t Racket Lists 
> — then point to data/ralis and show how to transliterate the 
> loop/append example like this 
> — optionally also show the more native Racket idiom 
> 
> 4. When anyone observers another blog/social media/whatever post on Racket is 
> slow because I come from Python, 
> 
> (a) point the posters to the page  or 
> (b) if it is a new case, write a section for this example then do (a) 
> 
> 
> If you want to help advertise Racket to others, this is an excellent way of 
> helping out. 
> 
> Thanks — Matthias 
> 
> [[ p.s. For my very first Python program (a couple of days before meeting 
> with GvR), I used Python’s append and was annoyed beyond belief. ]] 
> 
> 
> 
> -- 
> You received this message because you are subscribed to the Google Groups 
> "Racket Users" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to racket-users+unsubscr...@googlegroups.com 
> .
> For more options, visit https://groups.google.com/d/optout 
> .

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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Robby Findler]

This is very nice!

Robby

On Sat, Feb 2, 2019 at 10:37 PM Alex Harsanyi 
wrote:

>
> I put together some notes about available data structures in Racket, with
> some performance considerations.  It needs more work, but perhaps it can be
> used as a starting point and it can be added to the Racket wiki, if/when
> others consider it adequate:
>
> https://gist.github.com/alex-hhh/3cc5690a7f9c74543dab6c11344e6202
>
> I didn't write a "Python to Racket" guide, because I don't really know
> enough about Python to write such a document, and I also think that a more
> generic document is simpler to maintain and can be used by people who come
> from other languages as well.
>
> I also tried to keep the document short, the aim being to provide a
> competent programmer who is new to Racket with a 5 minute overview to its
> data structures and some links to the starting points in the
> documentation.  We can add things to it, but I think it is better to keep
> it short rather than comprehensive in this case -- after all, there is the
> Racket Guide and Racket Reference and these documents contain all the
> details.  Perhaps new documents can be added to the wiki, exploring other
> topics in more detail.
>
> I did not mention `ralist` because (1) I have no experience with it, but
> more importantly (2) the package is not part of the Racket distribution and
> has to be installed separately.  I don't it reflects well on Racket if we
> tell people to install a separate package if they want an efficient
> container...  I have no experience with `ralist`, but if it is indeed a
> good data structure and it has a potentially wide usage, it should be
> included in the default Racket installation.
>
> Alex.
>
> On Sunday, February 3, 2019 at 7:00:10 AM UTC+8, Matthias Felleisen wrote:
>>
>>
>>
>> Racket needs *you*. Please.
>>
>> The proper approach is to have short pages for different language
>> immigration groups: Python and R come to mind as obvious examples but I am
>> sure there are others.
>>
>> What I mean is we need help and *you* can help. Let me explain it with
>> the Python example:
>>
>> 1. Set up a page (wiki?) called “From Python to Racket”
>>
>> 2. Create two sections that are immediately visible from the top:
>>
>> — idioms
>> — performance pitfalls
>>
>> 3. In the specific case of Python, the second subsection needs to start
>> with a subsection on
>>
>> — Python Lists aren’t Racket Lists
>> — then point to data/ralis and show how to transliterate the
>> loop/append example like this
>> — optionally also show the more native Racket idiom
>>
>> 4. When anyone observers another blog/social media/whatever post on
>> Racket is slow because I come from Python,
>>
>> (a) point the posters to the page  or
>> (b) if it is a new case, write a section for this example then do
>> (a)
>>
>>
>> If you want to help advertise Racket to others, this is an excellent way
>> of helping out.
>>
>> Thanks — Matthias
>>
>> [[ p.s. For my very first Python program (a couple of days before meeting
>> with GvR), I used Python’s append and was annoyed beyond belief. ]]
>>
>>
>> --
> You received this message because you are subscribed to the Google Groups
> "Racket Users" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to racket-users+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>

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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Jens Axel Søgaard]

FWIW here is an overview over data structures in Racket:

https://stackoverflow.com/questions/27584416/in-racket-what-is-the-advantage-of-lists-over-vectors/27589146#27589146

/Jens Axel


Den søn. 3. feb. 2019 kl. 05.37 skrev Alex Harsanyi :

>
> I put together some notes about available data structures in Racket, with
> some performance considerations.  It needs more work, but perhaps it can be
> used as a starting point and it can be added to the Racket wiki, if/when
> others consider it adequate:
>
> https://gist.github.com/alex-hhh/3cc5690a7f9c74543dab6c11344e6202
>
> I didn't write a "Python to Racket" guide, because I don't really know
> enough about Python to write such a document, and I also think that a more
> generic document is simpler to maintain and can be used by people who come
> from other languages as well.
>
> I also tried to keep the document short, the aim being to provide a
> competent programmer who is new to Racket with a 5 minute overview to its
> data structures and some links to the starting points in the
> documentation.  We can add things to it, but I think it is better to keep
> it short rather than comprehensive in this case -- after all, there is the
> Racket Guide and Racket Reference and these documents contain all the
> details.  Perhaps new documents can be added to the wiki, exploring other
> topics in more detail.
>
> I did not mention `ralist` because (1) I have no experience with it, but
> more importantly (2) the package is not part of the Racket distribution and
> has to be installed separately.  I don't it reflects well on Racket if we
> tell people to install a separate package if they want an efficient
> container...  I have no experience with `ralist`, but if it is indeed a
> good data structure and it has a potentially wide usage, it should be
> included in the default Racket installation.
>
> Alex.
>
> On Sunday, February 3, 2019 at 7:00:10 AM UTC+8, Matthias Felleisen wrote:
>>
>>
>>
>> Racket needs *you*. Please.
>>
>> The proper approach is to have short pages for different language
>> immigration groups: Python and R come to mind as obvious examples but I am
>> sure there are others.
>>
>> What I mean is we need help and *you* can help. Let me explain it with
>> the Python example:
>>
>> 1. Set up a page (wiki?) called “From Python to Racket”
>>
>> 2. Create two sections that are immediately visible from the top:
>>
>> — idioms
>> — performance pitfalls
>>
>> 3. In the specific case of Python, the second subsection needs to start
>> with a subsection on
>>
>> — Python Lists aren’t Racket Lists
>> — then point to data/ralis and show how to transliterate the
>> loop/append example like this
>> — optionally also show the more native Racket idiom
>>
>> 4. When anyone observers another blog/social media/whatever post on
>> Racket is slow because I come from Python,
>>
>> (a) point the posters to the page  or
>> (b) if it is a new case, write a section for this example then do
>> (a)
>>
>>
>> If you want to help advertise Racket to others, this is an excellent way
>> of helping out.
>>
>> Thanks — Matthias
>>
>> [[ p.s. For my very first Python program (a couple of days before meeting
>> with GvR), I used Python’s append and was annoyed beyond belief. ]]
>>
>>
>> --
> You received this message because you are subscribed to the Google Groups
> "Racket Users" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to racket-users+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>


-- 
-- 
Jens Axel Søgaard

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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Alex Harsanyi]

I put together some notes about available data structures in Racket, with 
some performance considerations.  It needs more work, but perhaps it can be 
used as a starting point and it can be added to the Racket wiki, if/when 
others consider it adequate:

https://gist.github.com/alex-hhh/3cc5690a7f9c74543dab6c11344e6202

I didn't write a "Python to Racket" guide, because I don't really know 
enough about Python to write such a document, and I also think that a more 
generic document is simpler to maintain and can be used by people who come 
from other languages as well.

I also tried to keep the document short, the aim being to provide a 
competent programmer who is new to Racket with a 5 minute overview to its 
data structures and some links to the starting points in the 
documentation.  We can add things to it, but I think it is better to keep 
it short rather than comprehensive in this case -- after all, there is the 
Racket Guide and Racket Reference and these documents contain all the 
details.  Perhaps new documents can be added to the wiki, exploring other 
topics in more detail.

I did not mention `ralist` because (1) I have no experience with it, but 
more importantly (2) the package is not part of the Racket distribution and 
has to be installed separately.  I don't it reflects well on Racket if we 
tell people to install a separate package if they want an efficient 
container...  I have no experience with `ralist`, but if it is indeed a 
good data structure and it has a potentially wide usage, it should be 
included in the default Racket installation.

Alex.

On Sunday, February 3, 2019 at 7:00:10 AM UTC+8, Matthias Felleisen wrote:
>
>
>
> Racket needs *you*. Please. 
>
> The proper approach is to have short pages for different language 
> immigration groups: Python and R come to mind as obvious examples but I am 
> sure there are others. 
>
> What I mean is we need help and *you* can help. Let me explain it with the 
> Python example: 
>
> 1. Set up a page (wiki?) called “From Python to Racket” 
>
> 2. Create two sections that are immediately visible from the top: 
>  
> — idioms 
> — performance pitfalls 
>
> 3. In the specific case of Python, the second subsection needs to start 
> with a subsection on 
>
> — Python Lists aren’t Racket Lists 
> — then point to data/ralis and show how to transliterate the 
> loop/append example like this 
> — optionally also show the more native Racket idiom 
>
> 4. When anyone observers another blog/social media/whatever post on Racket 
> is slow because I come from Python, 
>
> (a) point the posters to the page  or 
> (b) if it is a new case, write a section for this example then do 
> (a) 
>
>
> If you want to help advertise Racket to others, this is an excellent way 
> of helping out. 
>
> Thanks — Matthias 
>
> [[ p.s. For my very first Python program (a couple of days before meeting 
> with GvR), I used Python’s append and was annoyed beyond belief. ]] 
>
>
>

-- 
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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Matthias Felleisen]

Racket needs *you*. Please. 

The proper approach is to have short pages for different language immigration 
groups: Python and R come to mind as obvious examples but I am sure there are 
others. 

What I mean is we need help and *you* can help. Let me explain it with the 
Python example: 

1. Set up a page (wiki?) called “From Python to Racket” 

2. Create two sections that are immediately visible from the top: 

— idioms 
— performance pitfalls 

3. In the specific case of Python, the second subsection needs to start with a 
subsection on 

— Python Lists aren’t Racket Lists 
— then point to data/ralis and show how to transliterate the 
loop/append example like this 
— optionally also show the more native Racket idiom 

4. When anyone observers another blog/social media/whatever post on Racket is 
slow because I come from Python, 

(a) point the posters to the page  or 
(b) if it is a new case, write a section for this example then do (a)


If you want to help advertise Racket to others, this is an excellent way of 
helping out. 

Thanks — Matthias

[[ p.s. For my very first Python program (a couple of days before meeting with 
GvR), I used Python’s append and was annoyed beyond belief. ]] 


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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Philip McGrath]

I am certain people coming from Python are confused by this, since I was
bitten by this very difference when I had to write some Python for the
first time in a while. (What do you mean append has side-effects?!?)

-Philip


On Sat, Feb 2, 2019 at 10:30 AM Robby Findler 
wrote:

> On Sat, Feb 2, 2019 at 9:23 AM George Neuner  wrote:
> >
> >
> > On 2/2/2019 9:38 AM, Robby Findler wrote:
> > > Lists seem like a common pitfall here, due to the overlap in
> > > terminology but not functionality/performance. Maybe the right thing
> > > is to add a library to data/ that is the python list data
> > > structure and point to it from the list documentation?
> >
> > The problem is that a Python "list" isn't a list at all - it's an
> > extensible vector of pointers.  Perhaps the right thing is to educate
> > Pythonistas that they really haven't been using lists.
>
> Although eduction is certainly a good goal(!), that seems like the
> long path to the helpful result for us. :)
>
> Robby
>
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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Robby Findler]

On Sat, Feb 2, 2019 at 9:23 AM George Neuner  wrote:
>
>
> On 2/2/2019 9:38 AM, Robby Findler wrote:
> > Lists seem like a common pitfall here, due to the overlap in
> > terminology but not functionality/performance. Maybe the right thing
> > is to add a library to data/ that is the python list data
> > structure and point to it from the list documentation?
>
> The problem is that a Python "list" isn't a list at all - it's an
> extensible vector of pointers.  Perhaps the right thing is to educate
> Pythonistas that they really haven't been using lists.

Although eduction is certainly a good goal(!), that seems like the
long path to the helpful result for us. :)

Robby

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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[George Neuner]

On 2/2/2019 9:38 AM, Robby Findler wrote:
Lists seem like a common pitfall here, due to the overlap in 
terminology but not functionality/performance. Maybe the right thing 
is to add a library to data/ that is the python list data 
structure and point to it from the list documentation?


The problem is that a Python "list" isn't a list at all - it's an 
extensible vector of pointers.  Perhaps the right thing is to educate 
Pythonistas that they really haven't been using lists.


I know nuances are lost on most people, but there's a huge difference 
between a list and a vector.


YMMV,
George

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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Sam Tobin-Hochstadt]

I agree with that 100%.

On Sat, Feb 2, 2019, 9:46 AM Robby Findler  Oh, right! Mentioning python in the list docs seems like it might help.
>
> Robby
>
> On Sat, Feb 2, 2019 at 8:45 AM Sam Tobin-Hochstadt 
> wrote:
>
>> Fortunately there are already libraries with good performance on these
>> operations for Racket, so we could point to the data/ralist library,
>> for example.
>>
>> Sam
>>
>> On Sat, Feb 2, 2019 at 9:38 AM Robby Findler
>>  wrote:
>> >
>> > Lists seem like a common pitfall here, due to the overlap in
>> terminology but not functionality/performance. Maybe the right thing is to
>> add a library to data/ that is the python list data structure
>> and point to it from the list documentation?
>> >
>> > Robby
>> >
>> > On Sat, Feb 2, 2019 at 12:28 AM Alex Harsanyi 
>> wrote:
>> >>
>> >> Someone asked recently for help on Reddit[1] with a Racket performance
>> issue.
>> >> The problem was they they were constructing a large list by appending
>> many
>> >> short lists repeatedly; their code was calling `(set!  result (append
>> result
>> >> shortList))` in a loop and this was slow (unsurprisingly.)
>> >>
>> >> While trying to help them out, it occurred to me that this person was
>> perhaps
>> >> translating a program from Python to Racket, maybe to evaluate
>> Racket.  The
>> >> problem is that list-append operations are efficient in Python, but the
>> >> natural corresponding choice in Racket, the `append` function, is
>> not.  I
>> >> wonder how many people are in a similar situation, where they try to
>> convert a
>> >> Python program to Racket, see that the performance is bad, and
>> conclude that
>> >> Racket is slow -- Every time Racket is mentioned on Reddit or HN there
>> is at
>> >> least one person mentioning that Racket is slow and sadly they may
>> even have
>> >> their own data to prove it.
>> >>
>> >> Given the recent discussion in this group about promoting Racket, I am
>> >> wondering what can we do to help this category of people?  These might
>> be
>> >> persons who never ask for help in any forum, after all the Racket
>> >> documentation is good enough to help anyone who is willing to read it.
>> >>
>> >> One improvement that I can think of is to add a performance
>> description to
>> >> each function that operates on the basic data structures (lists,
>> vectors,
>> >> hash-tables)
>> >>
>> >> What do others think?
>> >> Alex.
>> >>
>> >> [1]:
>> https://www.reddit.com/r/Racket/comments/am5r2w/how_to_read_a_file_linebyline_efficiently/
>> >>
>> >> --
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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Robby Findler]

Oh, right! Mentioning python in the list docs seems like it might help.

Robby

On Sat, Feb 2, 2019 at 8:45 AM Sam Tobin-Hochstadt 
wrote:

> Fortunately there are already libraries with good performance on these
> operations for Racket, so we could point to the data/ralist library,
> for example.
>
> Sam
>
> On Sat, Feb 2, 2019 at 9:38 AM Robby Findler
>  wrote:
> >
> > Lists seem like a common pitfall here, due to the overlap in terminology
> but not functionality/performance. Maybe the right thing is to add a
> library to data/ that is the python list data structure and
> point to it from the list documentation?
> >
> > Robby
> >
> > On Sat, Feb 2, 2019 at 12:28 AM Alex Harsanyi 
> wrote:
> >>
> >> Someone asked recently for help on Reddit[1] with a Racket performance
> issue.
> >> The problem was they they were constructing a large list by appending
> many
> >> short lists repeatedly; their code was calling `(set!  result (append
> result
> >> shortList))` in a loop and this was slow (unsurprisingly.)
> >>
> >> While trying to help them out, it occurred to me that this person was
> perhaps
> >> translating a program from Python to Racket, maybe to evaluate Racket.
> The
> >> problem is that list-append operations are efficient in Python, but the
> >> natural corresponding choice in Racket, the `append` function, is not.
> I
> >> wonder how many people are in a similar situation, where they try to
> convert a
> >> Python program to Racket, see that the performance is bad, and conclude
> that
> >> Racket is slow -- Every time Racket is mentioned on Reddit or HN there
> is at
> >> least one person mentioning that Racket is slow and sadly they may even
> have
> >> their own data to prove it.
> >>
> >> Given the recent discussion in this group about promoting Racket, I am
> >> wondering what can we do to help this category of people?  These might
> be
> >> persons who never ask for help in any forum, after all the Racket
> >> documentation is good enough to help anyone who is willing to read it.
> >>
> >> One improvement that I can think of is to add a performance description
> to
> >> each function that operates on the basic data structures (lists,
> vectors,
> >> hash-tables)
> >>
> >> What do others think?
> >> Alex.
> >>
> >> [1]:
> https://www.reddit.com/r/Racket/comments/am5r2w/how_to_read_a_file_linebyline_efficiently/
> >>
> >> --
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> Groups "Racket Users" group.
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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Sam Tobin-Hochstadt]

Fortunately there are already libraries with good performance on these
operations for Racket, so we could point to the data/ralist library,
for example.

Sam

On Sat, Feb 2, 2019 at 9:38 AM Robby Findler
 wrote:
>
> Lists seem like a common pitfall here, due to the overlap in terminology but 
> not functionality/performance. Maybe the right thing is to add a library to 
> data/ that is the python list data structure and point to it from 
> the list documentation?
>
> Robby
>
> On Sat, Feb 2, 2019 at 12:28 AM Alex Harsanyi  wrote:
>>
>> Someone asked recently for help on Reddit[1] with a Racket performance issue.
>> The problem was they they were constructing a large list by appending many
>> short lists repeatedly; their code was calling `(set!  result (append result
>> shortList))` in a loop and this was slow (unsurprisingly.)
>>
>> While trying to help them out, it occurred to me that this person was perhaps
>> translating a program from Python to Racket, maybe to evaluate Racket.  The
>> problem is that list-append operations are efficient in Python, but the
>> natural corresponding choice in Racket, the `append` function, is not.  I
>> wonder how many people are in a similar situation, where they try to convert 
>> a
>> Python program to Racket, see that the performance is bad, and conclude that
>> Racket is slow -- Every time Racket is mentioned on Reddit or HN there is at
>> least one person mentioning that Racket is slow and sadly they may even have
>> their own data to prove it.
>>
>> Given the recent discussion in this group about promoting Racket, I am
>> wondering what can we do to help this category of people?  These might be
>> persons who never ask for help in any forum, after all the Racket
>> documentation is good enough to help anyone who is willing to read it.
>>
>> One improvement that I can think of is to add a performance description to
>> each function that operates on the basic data structures (lists, vectors,
>> hash-tables)
>>
>> What do others think?
>> Alex.
>>
>> [1]: 
>> https://www.reddit.com/r/Racket/comments/am5r2w/how_to_read_a_file_linebyline_efficiently/
>>
>> --
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>> "Racket Users" group.
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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Robby Findler]

Lists seem like a common pitfall here, due to the overlap in terminology
but not functionality/performance. Maybe the right thing is to add a
library to data/ that is the python list data structure and
point to it from the list documentation?

Robby

On Sat, Feb 2, 2019 at 12:28 AM Alex Harsanyi 
wrote:

> Someone asked recently for help on Reddit[1] with a Racket performance
> issue.
> The problem was they they were constructing a large list by appending many
> short lists repeatedly; their code was calling `(set!  result (append
> result
> shortList))` in a loop and this was slow (unsurprisingly.)
>
> While trying to help them out, it occurred to me that this person was
> perhaps
> translating a program from Python to Racket, maybe to evaluate Racket.  The
> problem is that list-append operations are efficient in Python, but the
> natural corresponding choice in Racket, the `append` function, is not.  I
> wonder how many people are in a similar situation, where they try to
> convert a
> Python program to Racket, see that the performance is bad, and conclude
> that
> Racket is slow -- Every time Racket is mentioned on Reddit or HN there is
> at
> least one person mentioning that Racket is slow and sadly they may even
> have
> their own data to prove it.
>
> Given the recent discussion in this group about promoting Racket, I am
> wondering what can we do to help this category of people?  These might be
> persons who never ask for help in any forum, after all the Racket
> documentation is good enough to help anyone who is willing to read it.
>
> One improvement that I can think of is to add a performance description to
> each function that operates on the basic data structures (lists, vectors,
> hash-tables)
>
> What do others think?
> Alex.
>
> [1]:
> https://www.reddit.com/r/Racket/comments/am5r2w/how_to_read_a_file_linebyline_efficiently/
>
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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Thomas F. Burdick]

On February 2, 2019 7:28:12 AM GMT+01:00, Alex Harsanyi 
 wrote:
>Someone asked recently for help on Reddit[1] with a Racket performance 
>issue.
>The problem was they they were constructing a large list by appending
>many
>short lists repeatedly; their code was calling `(set!  result (append
>result
>shortList))` in a loop and this was slow (unsurprisingly.)

In addition to the general list-processing advice they were likely given, I 
suspect someone coming from Python might appreciate tconc structures. SRFI 117 
is one attempt at fleshing this out into a contemporary API. But just classic 
tconc and lconc are pretty useful to know and have at your fingertips.

-Thomas

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Re: [racket-users] Python's append vs Racket's append and helping novices understand the implications

[Neil Van Dyke]

Alex Harsanyi wrote on 2/2/19 1:28 AM:
One improvement that I can think of is to add a performance 
description to each function that operates on the basic data 
structures (lists, vectors, hash-tables)


Before complete coverage, perhaps two first steps:

* Try to think of the minority of procedures (and use cases?) that might 
be *surprisingly* expensive (either to anyone, or to users coming from 
some other languages), and focus first on the documentation for those.  
`append` is likely one, for people who don't yet understand lists well, 
or who aren't aware of more efficient patterns/idioms.  `list?` (or 
`listp` elsewhere in our Lisp family) is one that bit me and others, 
somehow not realizing it's potentially O(n) [1] (though apparently 
Racket now optimizes some cases of that, for immutable pairs[2]).  Those 
are the first two that come to mind, but I assume someone would find 
others by looking methodically through the documentation.


* Exposing lists based on pairs means programmers must understand the 
list model (list is not an opaque abstract data type), and it'll help 
them if they know some patterns for working with the model. Teach every 
Racketeer some old-school list processing.[3][4]  Maybe teach this 
before `for`-something (before they think "Aha!  Now I know the Racket 
way, which is pretty much the same as in many other languages I know!", 
and then they consider the finer points of lists and recursion to be 
esoteric stuff that maybe they don't learn well, soon).



[1] The current documentation even hides the recursive mathematical 
definition of a list in innocent-looking text, trying to trick users 
into the classic mistake! :)


[2] It looks like Racket C code now sometimes stores a bit with 
immutable pairs to cache list-ness, though the documentation's exact 
characterization of the performance of this isn't obvious from the C 
function alone.  Also, I don't see where in that function the 
PAIR_IS_NON_LIST flag is checked, for optimizing those cases. (BTW,


[3] https://m.xkcd.com/297/

[4] One day, I got all excited by Roombas, and accidentally typed an 
alist primer. 
https://www.neilvandyke.org/racket/roomba/#%28part._.Association._.List._.Primer%29


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[racket-users] Python's append vs Racket's append and helping novices understand the implications

[Alex Harsanyi]

Someone asked recently for help on Reddit[1] with a Racket performance 
issue.
The problem was they they were constructing a large list by appending many
short lists repeatedly; their code was calling `(set!  result (append result
shortList))` in a loop and this was slow (unsurprisingly.)

While trying to help them out, it occurred to me that this person was 
perhaps
translating a program from Python to Racket, maybe to evaluate Racket.  The
problem is that list-append operations are efficient in Python, but the
natural corresponding choice in Racket, the `append` function, is not.  I
wonder how many people are in a similar situation, where they try to 
convert a
Python program to Racket, see that the performance is bad, and conclude that
Racket is slow -- Every time Racket is mentioned on Reddit or HN there is at
least one person mentioning that Racket is slow and sadly they may even have
their own data to prove it.

Given the recent discussion in this group about promoting Racket, I am
wondering what can we do to help this category of people?  These might be
persons who never ask for help in any forum, after all the Racket
documentation is good enough to help anyone who is willing to read it.

One improvement that I can think of is to add a performance description to
each function that operates on the basic data structures (lists, vectors,
hash-tables)

What do others think?
Alex.

[1]: 
https://www.reddit.com/r/Racket/comments/am5r2w/how_to_read_a_file_linebyline_efficiently/

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