Re: Getting Started with Lua

[Ralph Hempel <rhempel@...>]

H. Conrad Cunningham wrote:
> On Wed, Jul 24, 2013 at 3:16 PM, Jay Carlson<nop@nop.com>  wrote:
> > To be fair, if your goal *is* to be able to build a SqueakVM- or Prescheme-like restricted Lua dialect which maps to C or machine instructions, getting "typical" bare metal ints into the language might help.
>
> I am still formulating my goals.  I had the following thoughts when
> choosing Lua:
>
> * It is a language that most of the students (in both the
> undergraduate programming languages class and graduate class) do not
> know, but it is simple and familiar enough in syntax that they should
> be able learn it quickly. I want to use something different, but not
> to have to devote much class time to teaching the language.

I cannot overstate the importance of this. My pbLua implementation for 
LEGO MINDSTORMS NXT was used in a uni level class for non-CS majors and 
one of the major benefits over the Java course the previous year was 
avoiding a long break-in period before the students could _use_ the 
language for anything interesting.

<http://ozark.hendrix.edu/~ferrer/roboticsBook/>

> * It seems to support programming in multiple paradigms reasonably
> well--procedural, functional, modular, "object-oriented" ,
> nonpreemptive multitasking, language-oriented (using LPEG), etc.  I
> want the students to think about programming in different ways.

And again, the REPL philosophy helps here. Students can cut and paste to 
a terminal, or simply reload the file into the interpreter. It's easy to 
try things this way or that way, or experiment and inspect machine state 
from the command line.

> * It seems simple and small enough that its design and implementation
> could be an object of study itself.

And for advanced students, you can at least use the Lua source as an 
example of minimally documented source, but well documented APIs. And 
then move on to a C binding for OS level stuff. For example, I modified 
"luahidapi" in about 10 minutes to allow open to support a serial number 
parameter.

> There are too many interesting threads to follow in one semester.
>
> Of course a disadvantage of Lua for me is that I normally prefer to
> work with strictly and strongly typed languages and tend to be
> opinionated about good programming "policy".  :)
>
> Also, I have not yet determined what is the best way to structure a
> Lua "software family" as represented by the group of interpreters in
> the last bullet above.

That's the hardest part - you need to play with the language intensely 
for about 2 to 4 weeks. The magic of metatables is the stumbling block I 
had to overcome. It's very similar to the hurdle of pointers for 
students of C - if you don't understand that, then you'll never become 
really fluent.

Cheers, and good luck - you sound like an excellent professor!

Ralph