[M3devel] latest longint file size diffs

[Tony Hosking]

On 9 Jan 2010, at 00:50, Jay K wrote:

> I don't know the precedence but agreed:
> 
> 
> > OR (IsEqual (Base(a), Int.T, NIL) AND IsEqual (Base(b), LInt.T, NIL))
> > OR (IsEqual (Base(a), LInt.T, NIL) AND IsEqual (Base(b), Int.T, NIL)))
> 
> I was being sort of lazy.
> I've never touched the front end and it was critical I be able to make
> a small change and see fairly precisely the expected change, even
> if I didn't get all cases.
> 
> This is I'm sure why I had to add some VAL/ORD uses, to convert "UINT32"
> in the Win32 code to INTEGER or LONGINT.

Yes, that would be why.

> Also, I really think mixed arithmetic is ok.

But are you ok with:

(LAST(INTEGER) + 1) = FIRST(INTEGER)

while

(LAST(INTEGER) + 1L) # FIRST(INTEGER)

?

I find such things to be difficult to explain to the novice programmer.  Modula-3 was designed using the "principle of least surprise" and I frankly find the above to be very surprising!

> 
>  - Jay
> 
> 
> > From: hosking at cs.purdue.edu
> > Date: Sat, 9 Jan 2010 00:37:42 -0500
> > To: jay.krell at cornell.edu
> > CC: m3devel at elegosoft.com
> > Subject: Re: [M3devel] latest longint file size diffs
> > 
> > Looking at your code, I think the assignability test for ordinals should be more like:
> > 
> > IF (IsEqual (Base(a), Base(b), NIL)
> > OR IsEqual (Base(a), Int.T, NIL) AND IsEqual (Base(b), LInt.T, NIL)
> > OR IsEqual (Base(a), LInt.T, NIL) AND IsEqual (Base(b), Int.T, NIL))
> > AND GetBounds (a, min_a, max_a)
> > AND GetBounds (b, min_b, max_b) THEN
> > (* check for a non-empty intersection *)
> > min := min_a; IF TInt.LT (min, min_b) THEN min := min_b; END;
> > max := max_a; IF TInt.LT (max_b, max) THEN max := max_b; END;
> > RETURN TInt.LE (min, max);
> > ELSE
> > RETURN FALSE;
> > END;
> > 
> > That way CARDINAL and other subranges fall right out.
> > 
> > Antony Hosking | Associate Professor | Computer Science | Purdue University
> > 305 N. University Street | West Lafayette | IN 47907 | USA
> > Office +1 765 494 6001 | Mobile +1 765 427 5484
> > 
> > 
> > 
> > 
> > On 8 Jan 2010, at 06:13, Jay K wrote:
> > 
> > > Attached is my latest work here.
> > > With the compiler changes (in the diff), I was able to
> > > elminate most uses of VAL(expr, LONGINT).
> > > There's something slightly off such that I had
> > > to add a very small number, like two.
> > > 
> > > 
> > > The compiler change is newer than earlier.
> > > For example you can now assign CARDINAL to LONGINT.
> > > I didn't do it, but you should also be able to add/subtract/etc.
> > > mixing CARDINAL and LONGINT.
> > > 
> > > 
> > > FOR statements also don't allow the level of mixing
> > > that they should.
> > > 
> > > 
> > > I'm hoping to get agreement soon just from the diffs
> > > but if necessary I'll look how to create a branch.
> > > My general worry about branches is developers just
> > > go off on their own in a branch and it's impossible to
> > > get anyone to look at it, they are busy enough with one branch,
> > > let alone multiple..
> > > 
> > > 
> > > - Jay
> > > <dif8.txt>
> > 

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