Bloc of code in tiers programming language

Richard O'Keefe wrote
> I did not mean "course of instruction on the topic of continuations",
> I meant "that class whose name is Continuation in the Smalltalk image."
> In a Playground, type Continuation and then Control-B.

Of course...  My inexperience again, coupled with hopes for a course of
instruction with examples.  However, the browser and source code are
sufficient, and I do need to read more ST code.

Having read your answers to others' questions, I'm impressed with the depth
of your knowledge and your eloquence (and patience) in explaining the
concepts and techniques.  The level of detail, examples, and notes on usage
are what I've been looking for.

-t




--
Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Hi,

Is nice to see this similitude between Lua and Pharo. We have been using
both in the Grafoscopio[1] project, because Lua is Pandoc's default
choice for embedded scripting language, and is pretty fast on the
Abstract Syntax Tree filters.

[1] https://mutabit.com/grafoscopio/index.en.html

For me Lua and Pharo are kind on opposite sides of the programming
spectrum/experience but is nice to see this conceptual connections.
Hopefully we, at the local hackerspace, will be able to explore the
Lua+Pharo bridge more and showcase them here.

Cheers,

Offray

On 16/05/19 1:18 p. m., Brainstorms wrote:

Hi Offray,

You probably know that you can develop Lua using OOP techniques, so they're
not so opposite for me, at least.  There is a significant difference as far
as their OOP styles, however: Lua OOP is prototype-based, not class-based.  

But you can fashion class(like) objects in Lua and program as though classes
existed -- albeit with some quirks taken into account (beyond the obvious
message-vs-function call difference).  The important thing is that you can
enjoy the benefits of using OO design patterns with Lua.

Lua has dynamic typing, every data type is first-class, it has a nil value,
inheritance (via metatables), closures, coroutines, limited reflection
(which you could possibly enhance through its C interface), and a nice C API
for gluing other code/languages together.  Much of its functionality is
obtained through included external libraries (most of which are written in
C).

What I hope to see is a nice FFI for Pharo that allows connection to Lua
code.  With that, I can glue Pharo to anything...  We've been using it to
automate LabVIEW applications.  I want to automate LabVIEW with Pharo as
well.

-t


Offray Vladimir Luna Cárdenas-2 wrote




--
Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Hi t,

Yes, I know that Lua support OOP, with several implementations and using
metatables. I have not looked in detail. But the idea of shared
similarities while being at opposite extremes of the programming
spectrum/experience is more related with both sharing minimalist
concepts applied everywhere (objects and messages for Pharo, tables and
functions for Lua), but one provided a full IDE/GUI and being tied with
a programming paradigm, which makes it great for agile prototyping,
while the other offers just the bare minimum and you arm your puzzle
from there regarding tools, paradigms, which makes it great for embedding.

Cheers,

Offray

On 17/05/19 3:29 p. m., Brainstorms wrote:

Hi Offray,

Yes, I definitely agree with you that Lua does not have the nice development
environment of Pharo (what other language does?), and is very bare-bones, as
it was originally intended for embedded applications.  I've gone through
nearly all of the online version of the Pharo MOOC now, and the ease of
building a web app with Pharo+Seaside is /amazing/.  (That's reason enough
to adopt Pharo!)  I'm now looking at Spec and how to work with that to make
GUI apps.  I can't do web apps in Lua, nor is there a GUI in Lua.

For that matter, with Lua there is no interaction with the OS, no sockets,
and very minimal file system interaction (that's actually built into Lua --
it doesn't even know what a directory is).  All of these capabilities can be
had in Lua, but they must be provided by external libraries -- even the
ability to interact via a terminal command line is typically done via a
small C app that wraps a Lua "state".  Lua is tiny.  Tiny, but powerful.

So I see that as an advantage, and a compliment to Pharo.  Seaside may be an
external library to Pharo, but much of "the rest" is built-in, and comes
with a nice OS/IDE to wrap it all up and keep things together.  Did not
Smalltalk-80 invent the concept of a container, which is becoming all the
rage in IT today?  Yet another first for ST..?

So I guess that's my beginner impression of Pharo: a great environment that
lives in a container.  (I'm learning how to implement containers and
implement /in/ containers now, too.)  How easy is it to cross that boundary
and interact with the rest of the world?  Maybe another way Lua and Pharo
are dissimilar?

Example: I automate hardware... Can I use Pharo to interact with
instrumentation over USB?

-Ted


Offray Vladimir Luna Cárdenas-2 wrote




--
Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Hi Ted,

On 17/05/19 6:38 p. m., Brainstorms wrote:
> Hi Offray,
>
> Yes, I definitely agree with you that Lua does not have the nice development
> environment of Pharo (what other language does?), and is very bare-bones, as
> it was originally intended for embedded applications.  


Yep, Pharo and other Smalltalk based IDEs are unbeatable as programming
experiences. What they have changed in my, is my look for other similar
experiences. In fact was going from an interactive first computing
experience that I explored things like Squeak, Etoys, Bots Inc,
IPython/Jupyter and Pharo. Trying to get something similar in Lua has
point me towards Zero Brane Studio (ZBS), which is (like Pharo) a Lua
IDE made on Lua itself.


> I've gone through
> nearly all of the online version of the Pharo MOOC now, and the ease of
> building a web app with Pharo+Seaside is /amazing/.  (That's reason enough
> to adopt Pharo!)  I'm now looking at Spec and how to work with that to make
> GUI apps.  I can't do web apps in Lua, nor is there a GUI in Lua.

Spec and making GUI was the way I started my exploration with Pharo.
Particularly using the Spec-GT bridge to create interactive notebooks in
Grafoscopio. In my case, works better when you have a "real world"
example to learn/solve in your programming environment. ZBS is made on
Lua using Wx Widgets for Lua, but as you point after, it is an extra
library. On the web front I saw some Seaside and Aida Web, but now I'm
more into and even more minimalist approach using Teapot. Even I have a
pretty alpha stuff combining Teapot with Material Design Light and
Fossil at:

https://mutabit.com/repos.fossil/brea/

>
> For that matter, with Lua there is no interaction with the OS, no sockets,
> and very minimal file system interaction (that's actually built into Lua --
> it doesn't even know what a directory is).  All of these capabilities can be
> had in Lua, but they must be provided by external libraries -- even the
> ability to interact via a terminal command line is typically done via a
> small C app that wraps a Lua "state".  Lua is tiny.  Tiny, but powerful.
Yes I like this pretty minimal setup for Lua. In fact I found it (again)
while working on reproducible research and publishing, as the extension
language for Pandoc and LaTeX (via LuaTeX).
>
> So I see that as an advantage, and a compliment to Pharo.  Seaside may be an
> external library to Pharo, but much of "the rest" is built-in, and comes
> with a nice OS/IDE to wrap it all up and keep things together.  Did not
> Smalltalk-80 invent the concept of a container, which is becoming all the
> rage in IT today?  Yet another first for ST..?
I remember some talk in Twitter with the Docker people about how
Smalltalk was an inspiration of the containers idea, but I can't locate
it again.
>
> So I guess that's my beginner impression of Pharo: a great environment that
> lives in a container.  (I'm learning how to implement containers and
> implement /in/ containers now, too.)  How easy is it to cross that boundary
> and interact with the rest of the world?  Maybe another way Lua and Pharo
> are dissimilar?
In my case, I interact with the external world via formats and DOMs
using parsers for JSON, HTML, CVS and so on and some times callings to
the OS. No obstacles there. Pharo is a pretty well suited environment to
interact with the external world on data visualization/processing issues
for reproducible research and publishing, while it helps me in keep
incidental complexity away, being a pretty self contained environment.
>
> Example: I automate hardware... Can I use Pharo to interact with
> instrumentation over USB?

Yes. There is a Pharo things project and Phratch (Arduido + Pharo +
Scratch) which use Pharo to interact with hardware.

Cheers,

Offray

On 15. 5. 2019 15:44, Tomaž Turk wrote:
> In javascript I believe is
>
> var f = function(x) { return Math.cos(x) + x; }
> var df = function(x) { return f(x + 1e-8) - f(x) * 1e8; }

You should use modern JS for comparision, though, so:

const f = x => Math.cos(x) + x;
const df = x => (f(x + 1e-8) - f(x)) * 1e8;

(fixed the operator precedence as well)

Herby

P.S.: I would parametrize the epsilon, as well as function, so

const deriv = epsilon => f => x => (f(x + epsilon) - f(x)) * epsilon;
const df = deriv(1e8)(f);

Thanks for the update.

Hilaire

--
Dr. Geo
http://drgeo.eu