Re: [stack] Syntax for combinators

Manfred Von Thun <[email protected]> wrote:
> Question: which level is best? Safety bought by inflexible rigidity, or
> flexibility at the cost of obfuscation? I¹ll leave it at that. Pick your
> level and tell us about it.

I think one of the great advances of Joy over Forth was its ability to
pass code to combinators. Going back to a fixed syntax would be a
pity. Safety can be acquired at less cost by adding some typechecking.

However, some of Joy's combinators might be a little overdone. 'ifte'
takes 3 quotations; that's a lot. I'd like to be able to express
'else' without having to go so deep on the stack. What if the 'if'
combinator left a conditional token on the stack, to be picked up by
an 'else' combinator?

[if-part] [conditional] if [else-part] else

alternately, if you really like traditional syntax,

[conditional] if [if-part] else [else-part] endif

The same implementation would work for more complex conditionals:

[action-choice] decisiontable
   [decision-part] decision
   [decision-part] decision
   [decision-part] decision ...
endtable

An 'if' would build a two-choice decision table. A full decision table
could have any number of choices.

>  - Manfred

-Billy