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Using "HasDomain" with a variable Domain parameter e.g. HasDomain(MyRuntimeVariableDomain,Term)

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Foothill Ranch
Joined: 04 Oct 2016
Posts: 9

PostPosted: 20 May 2017 17:57    Post subject: Using "HasDomain" with a variable Domain parameter e.g. HasDomain(MyRuntimeVariableDomain,Term) Reply with quote

For retrieval of Terms from a Chain, can the "HasDomain" Domain parameter be set with a runtime variable (and reset during backtracking)?

Alternatively, I thought you could create a Domain with all of the Domains you would ever need (see below) and use that with HasDomain. My example below works for the first Domain (customers), but fails during the first backtrack, after successfully working with the first Domain (customers).
myData = c(customers);p(part_name, iD, customer_name).

Am I doomed to creating a Clause for each Chain solely for the purpose of setting the HasDomain parameter?

The dream is to scan through DB Chains dumping out the Terms as it backtracks. Below is the error I get during backtracking and my code snippet. Note that the Chain Name and Chain Domain are the same (e.g. Chain 'customers" has one Domain also named "customers"

DB Name = Common.dba
NoOfTerms=8 MemSize=5968 DbaSize=6422 Free=2304217088
Chain name = customers
Term: customer("S1 Joe Fraser","S1 LA Ca")
Term: customer("S2 John Smith","S2 RSM Ca")
Term: customer("Joe Blow","Portland OR")
Term: customer("Sally Doe","Seattle Wa")
Chain name = parts
Exception in module: OneClass.exe
c:\program files (x86)\visual prolog 7.5\pfc\collection\algebraic\redblacktree\redblacktree.pro(252) : error r304: Invalid binary for the do
main 'data::customers' in ::toTerm( $[53,00,31,00,20,00,57,00,72,00 ... ] )

C:\Users\Administrator\Documents\Visual Prolog Projects\OneClass\Exe>pause
Press any key to continue . . .

    stdIO::write("\nChain name = ",MyChain),
% hasDomain(MyChain,SomeTerm),
%Above is what I wish would work because MyChain (by design) always equals the Chain's Term Domain.
   hasDomain(customers,SomeTerm), %Always works for the customers Chain
   MyDB:chain_terms(MyChain,SomeTerm, _), %Get the Term
   stdIO::write("\nTerm: ",SomeTerm), %Print it
   fail. %Backtracking to read the "parts" and "shipments" Chains and their Terms

/* notes */
% hasDomain(parts,SomeTerm),        %What I need for the first backtrack
% hasDomain(shipments,SomeTerm), %What I need for the second backtrack
% hasDomain(myData,SomeTerm),    %Trying a Domain with the 3 Domains above (customers, parts and Shipments). Always works for the customers Chain, but fails on backtracking (parts Domain)
/* notes */

partChain = "parts".
customerChain = "customers".
shipmentChain ="shipments".
%myData = c(customers);p(parts);s(shipments). %Fails on backtrack
%myData = p(parts);s(shipments);c(customers). %Fails on backtrack
myData = c(customers);p(part_name, iD, customer_name);s(chaindb::ref,chaindb::ref). %Fails on backtrack

customers = customer(customer_name,address).
parts = part(part_name, iD, customer_name).
shipments = shipment(chaindb::ref,chaindb::ref).

Any thoughts?
Thanks in advance.
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Martin Meyer

Frankfurt a.M., Germany
Joined: 14 Nov 2002
Posts: 223

PostPosted: 20 May 2017 21:01    Post subject: Reply with quote

Hi Larry,

maybe you are looking for a construction like this one:

    customerChain = "customers".
    partChain = "parts".
    shipmentChain ="shipments".

    part_name = string.
    iD = unsigned.
    customer_name = string.
    address = string.

    customers = customer(customer_name, address).
    parts = part(part_name, iD, customer_name).
    shipments = shipment(chaindb::ref, chaindb::ref).

    myData =
        p(part_name, iD, customer_name);
        s(chaindb::ref, chaindb::ref).

class predicates
    insertSomeTestData : (chainDB MyDB).
    insertSomeTestData(MyDB) :-
        MyDB:chain_insertz(customerChain, customer("S1 Joe Fraser", "S1 LA Ca"), _Customer_RefNumber_1),
        MyDB:chain_insertz(customerChain, customer("S2 John Smith", "S2 RSM Ca"), Customer_RefNumber_2),
        MyDB:chain_insertz(customerChain, customer("Joe Blow", "Portland OR"), _Customer_RefNumber_3),
        MyDB:chain_insertz(customerChain, customer("Sally Doe", "Seattle Wa"), _Customer_RefNumber_4),
        MyDB:chain_insertz(partChain, part("keyboard", 1, "S2 John Smith"), Part_RefNumber_1),
        MyDB:chain_insertz(partChain, part("mouse", 2, "S2 John Smith"), Part_RefNumber_2),
        MyDB:chain_insertz(partChain, part("monitor", 3, "Sally Doe"), _Part_RefNumber_3),
        MyDB:chain_insertz(shipmentChain, shipment(Customer_RefNumber_2, Part_RefNumber_1), _Shipment_RefNumber_1),
        MyDB:chain_insertz(shipmentChain, shipment(Customer_RefNumber_2, Part_RefNumber_2), _Shipment_RefNumber_2).

class predicates
    getChainInfo : (chainDB MyDB).
    getChainInfo(MyDB) :-
            stdIO::write("\nChain name = ", MyChain),
            MyData = getChainInfo(MyDB, MyChain),
                stdIO::write("\n Term: ", MyData),

class predicates
    getChainInfo : (
        chainDB MyDB,
        string MyChain)
        -> myData MyData
    getChainInfo(MyDB, customerChain) = c(Customer) :-
        MyDB:chain_terms(customerChain, Customer, _).
    getChainInfo(MyDB, partChain) = p(PartName, ID, CustomerName) :-
        MyDB:chain_terms(partChain, Part, _),
        part(PartName, ID, CustomerName) == Part.
    getChainInfo(MyDB, shipmentChain) = s(RefNumberA, RefNumberB) :-
        MyDB:chain_terms(shipmentChain, Shipment, _),
        shipment(RefNumberA, RefNumberB) == Shipment.

    run() :-
        MyDB = chainDB::db_create("MyDB", chainDB::in_memory),

It outputs:
    Chain name = customers
    Term: c(customer("S1 Joe Fraser","S1 LA Ca"))
    Term: c(customer("S2 John Smith","S2 RSM Ca"))
    Term: c(customer("Joe Blow","Portland OR"))
    Term: c(customer("Sally Doe","Seattle Wa"))
    Chain name = parts
    Term: p("keyboard",1,"S2 John Smith")
    Term: p("mouse",2,"S2 John Smith")
    Term: p("monitor",3,"Sally Doe")
    Chain name = shipments
    Term: s(131072,327680)
    Term: s(131072,393216)

Regards Martin
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Foothill Ranch
Joined: 04 Oct 2016
Posts: 9

PostPosted: 21 May 2017 0:44    Post subject: Reply with quote

Hi Martin,
Thanks for the quick reply.
I was trying to have a single generic clause to handle all Domains, but the truth is; when I start creating the Prolog program that I really want to create, each Domain will need separate handling anyway. Your sample code is very clean and looks like exactly what I will want for my real world program.

Also, now I see how to setup MyData to accept all 3 Domains. All good stuff...
Thank you!
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