[Aldor-l] Source documentation

[Ralf Hemmecke]

On 04/25/2009 01:20 AM, David Casperson wrote:
> Hi Pippijn,
> 
> this is just from memory, but you can change from curly to piled any
>  time that you encounter a
> 
> #pile
> 
> and that the two goals can nest in relatively arbitrary ways.
> 
> Speaking solely from the point of view of someone writing tools, the
>  piled text is a pain to parse.

Well, the Python people should have some experience with program layout
using something equivalent to #pile. So there must be a way to be able
to work nicely with #pile mode. ;-)

> ------------------------------------------------------------------------
>  A related question: is piling important? Should its support be high 
> priority? (Especially to you, Ralf.)

For me, #pile is definitely not important.

I have a dislike for pile mode because of code like the following from
the Axiom library...

1:UnivariatePuiseuxSeriesWithExponentialSingularity(R,FE,var,cen):_
2:  Exports == Implementation where
3:  R   : Join(OrderedSet,RetractableTo Integer,_
4:             LinearlyExplicitRingOver Integer,GcdDomain)

The indentation of line 2 is completely irrelevant because of the _ in
line 1. The same applies for line 2. But as far as I remember, there was
a rule that Axiom would automatically continue a line when a closing
parenthesis is missing. So the _ on line 3 would be unnnecessary.
(See page 888 of (Tim's version) of the Axiom book or
http://www.axiom-developer.org/axiom-website/hyperdoc/axbook/section-10.2.xhtml)

Does someone (unfamiliar with SPAD) really understand the following?
-----
The definition of drawRibbons consists of a pile of expressions to be 
executed one after another. Each expression of the pile is indented at 
the same level. Lines 4-7 designate one single expression: since lines 
5-7 are indented with respect to the others, these lines are treated as 
a continuation of line 4. Also since lines 5 and 7 have the same 
indentation level, these lines designate a pile within the outer pile.
-----

How much do you like the following from
http://www.axiom-developer.org/axiom-website/hyperdoc/axbook/section-5.2.xhtml

---BEGIN

Blocks can be used in the arguments to functions.  (Here  h is
assigned  2.1+3.5.)

h := 2.1 +
    1.0
    3.5

---END

And how much do you like the next thing?

---BEGIN
Here the second argument to eval is  x=z, where the value of z is 
computed in the first line of the block starting on the second
line.

eval(x**2 - x*y**2,
      z := %pi/2.0 - exp(4.1)
      x = z
    )

The interesting part is also the closing parenthesis. Could I write it 
in column 1? Or column 6, so that it alligns with "x=z"?

Ralf