Re: Nested Relations / RVAs / NFNF

neo55592_at_hotmail.com (Neo) wrote in message news:<4b45d3ad.0410312011.312f0b51_at_posting.google.com>...
> > how would you represent "two kilograms" in a program?
>
> Below code is equivalent to the script listed earlier. The 2Kg is
> created by calling XDb2's API. The actual 2Kg exists in the db not in
> the program. General steps are similar for any other thing.
>
> void main()
> {
> // Create unit
> // Equivalent to NLI_create2("*unit.cls=thing");
> pUnit = T_create();
> T_Name_relate(pUnit, "unit");
> T_relate(pUnit, pCls, pThing);
>
> // Create unit > kg
> // Equivalent to NLI_create2("*kg.cls=unit");
> pKg = T_create();
> T_Name_relate(pKg, "kg");
> T_relate(pKg, pCls, pUnit);
>
> // Create qty
> // Equivalent to NLI_create2("*qty.cls=thing");
> pQty = T_create();
> T_Name_relate(pQty , "qty");
> T_relate(pQty , pCls, pThing);
>
> // Create qty > 2
> // Equivalent to NLI_create2("*2.cls=qty");
> p2 = T_create();
> T_Name_relate(p2, "2");
> T_relate(p2, pCls, pQty);
>
> // Create mass
> // Equivalent to NLI_create2("*mass.cls=thing");
> pMass = T_create();
> T_Name_relate(pMass, "mass");
> T_relate(pMass, pCls, pThing);
>
> // Create mass > 2Kg
> // Equivalent to NLI_create2("*");
> // NLI_create2("it.cls=mass");
> // NLI_create2("it.qty=2");
> // NLI_create2("it.unit=kg");
> p2Kg = T_create();
> T_relate(p2Kg, pCls, pMass);
> T_relate(p2Kg, pQty, p2);
> T_relate(p2Kg, pUnit, pKg);
>
> // Assume, program restarts
> // Find 2Kg in db
> pQuery = NLI_select2("%.cls=mass & %.qty=2 & %.unit=kg);
> p2Kg = X2(pQuery);
>
> // Use code similar to above section to get pCls, pQty, pUnit
>
> // Get p2Kg's class
> p2Kg_cls = S_SV_getO(p2Kg, pCls);
>
> // Get p2Kg's qty
> p2Kg_qty = S_SV_getO(p2Kg, pQty);
>
> // Get p2Kg's unit
> p2Kg_unit = S_SV_getO(p2Kg, pUnit);
>
> // Print "mass 2 kg"
> sCls = T_Name_get(p2Kg_cls);
> sQty = T_Name_get(p2Kg_qty);
> sUnit = T_Name_get(p2Kg_unit);
> printf("%s %s %s", sCls, sQty, sUnit);
>
> // Also prints "mass 2 kg" which is auto-generated
> s2Kg = T_Name_get(p2kg);
> printf("%s", s2Kg);
>
> // p2Kg is a ptr/handle to a thing in db which represents 2kg
> // And yes, things are normalized within db,
> // including the symbol 't' in "unit" and "qty"
> }

Wow. Well, I'm sold. Anybody else ?

Cheers,

• Tony

PS. ;) Received on Tue Nov 02 2004 - 02:05:44 CET