[m-rev.] Extended inst syntax documentation

[David Overton]

On Wed, Feb 12, 2003 at 11:46:19AM +1100, Ralph Becket wrote:
> +A more concise, alternative syntax exists for @samp{bound} instantiatedness
> +trees:
> +
> + at example
> +:- inst listskel ---> [] ; [free | listskel].
> + at end example
> +
> +which is equivalent to writing
> +
> + at example
> +:- inst listskel == bound([] ; [free | listskel]).
> + at end example
> +

Lists might not be the clearest example to use here, given the special
syntax for list construction.  It might be better to use something like

:- inst maybe ---> no ; yes(ground).

>  As execution proceeds, variables may become more instantiated.
>  A @dfn{mode mapping} is a mapping
>  from an initial instantiatedness tree to a final instantiatedness tree,
> @@ -2199,10 +2212,9 @@
>  :- type operation
>          --->    lookup(key, data)
>          ;       set(key, data).
> -:- inst request ==
> -        bound(  lookup(ground, free)
> -        ;       set(ground, ground)
> -        ).
> +:- inst request
> +	--->	lookup(ground, free)
> +        ;       set(ground, ground).
>  :- mode create_request == free >> request.
>  :- mode satisfy_request == request >> ground.
>  @end example
> @@ -2211,7 +2223,7 @@
>  For example, the following declaration 
>  
>  @example
> -:- inst listskel(Inst) == bound( [] ; [Inst | listskel(Inst)] ).
> +:- inst listskel(Inst) ---> [] ; [Inst | listskel(Inst)].
>  @end example
>  
>  @noindent
> @@ -2660,6 +2672,9 @@
>  needed on backtracking.  This means that unique modes are generally
>  only useful for code whose determinism is @samp{det} or @samp{cc_multi}
>  (@pxref{Determinism}).
> +
> +Unlike @samp{bound} instantiatedness trees, there is no alternative
> +syntax for @samp{unique} instantiatedness trees.
>  
>  @node Backtrackable destructive update
>  @section Backtrackable destructive update
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-- 
David Overton                  Uni of Melbourne     +61 3 8344 1354
dmo at cs.mu.oz.au                Monash Uni (Clayton) +61 3 9905 5779
http://www.cs.mu.oz.au/~dmo    Mobile Phone         +61 4 0337 4393
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