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hekate:xtt [2008/04/30 13:52] gjn attributive lang and rules imported |
hekate:xtt [2019/06/27 15:49] (current) |
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| ===== Attributive language ===== | ===== Attributive language ===== | ||
| - | ====== Introduction ====== | + | ==== Introduction ==== |
| We need attributes to build descriptions of state of the system. | We need attributes to build descriptions of state of the system. | ||
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| * attribute algebra, what can we do with attributes, expressions, and how we do it | * attribute algebra, what can we do with attributes, expressions, and how we do it | ||
| - | ===== Attribute description ===== | + | ==== Attribute description ==== |
| - | ==== Type ==== | + | === Type === |
| For each attribute a type has to be stated. | For each attribute a type has to be stated. | ||
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| - | ==== Primitive Types ==== | + | === Primitive Types === |
| What do we need types for anyway? | What do we need types for anyway? | ||
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| While it might look similar to structures, it still does have a //different// semantics. | While it might look similar to structures, it still does have a //different// semantics. | ||
| - | === Type mappings === | + | == Type mappings == |
| Current type specs has Prolog, SQL and Java mapping in mind (we map to Java object, not basic types, so Integer, not int). | Current type specs has Prolog, SQL and Java mapping in mind (we map to Java object, not basic types, so Integer, not int). | ||
| * For RDB2Prolog see [[http://www.swi-prolog.org/packages/odbc.html#sec:2.6|SWI ODBC]] | * For RDB2Prolog see [[http://www.swi-prolog.org/packages/odbc.html#sec:2.6|SWI ODBC]] | ||
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| - | ==== Domains ==== | + | === Domains === |
| A domain is a discrete, finite set of allowed attribute values. | A domain is a discrete, finite set of allowed attribute values. | ||
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| Additionally a set of values, narrowing the above, can be introduced. | Additionally a set of values, narrowing the above, can be introduced. | ||
| - | === Ordered symbolic domains === | + | == Ordered symbolic domains == |
| In the original XTT there was a feature called //enum//. | In the original XTT there was a feature called //enum//. | ||
| This was in fact an ordered symbolic domain. | This was in fact an ordered symbolic domain. | ||
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| This corresponds to the so-called linguistic variables in other formalisms. | This corresponds to the so-called linguistic variables in other formalisms. | ||
| - | ==== Contexts ==== | + | === Contexts === |
| In the original XTT attributes could be used in four contexts: | In the original XTT attributes could be used in four contexts: | ||
| conditional, assert, retract, decision. | conditional, assert, retract, decision. | ||
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| * decision context | * decision context | ||
| - | ==== Values ==== | + | === Values === |
| Attributes can have atomic or non-atomic values (multiple) -- this has to be specified explicitly. | Attributes can have atomic or non-atomic values (multiple) -- this has to be specified explicitly. | ||
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| Upon setting attribute value the same notation as for the domains should be used (a sum of ranges or values), i.e. S=<5,8>u{3} | Upon setting attribute value the same notation as for the domains should be used (a sum of ranges or values), i.e. S=<5,8>u{3} | ||
| - | ==== Description ==== | + | === Description === |
| In a general sense, an attribute | In a general sense, an attribute | ||
| * is identified by name | * is identified by name | ||
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| - | ==== Grouped attributes ==== | + | === Grouped attributes === |
| - | === The original desc === | + | == The original desc == |
| (as from the //progrulesext// papers)) | (as from the //progrulesext// papers)) | ||
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| </code> | </code> | ||
| - | === Discussion === | + | == Discussion == |
| Now, considering the primitive types discussion, as well as type system extension possiblity I would refine the GA proposal, as it might/should? be the key to type expressiveness. | Now, considering the primitive types discussion, as well as type system extension possiblity I would refine the GA proposal, as it might/should? be the key to type expressiveness. | ||
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| - | ===== Defining Attributes ===== | + | ==== Defining Attributes ==== |
| ...or the short attribute quickstart with examples. | ...or the short attribute quickstart with examples. | ||
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| The CASE tools should support a concept of an attribute library, where some predefined types are available. | The CASE tools should support a concept of an attribute library, where some predefined types are available. | ||
| - | ===== Attributes and ARD ===== | + | ==== Attributes and ARD ==== |
| We should try to establish relationship/s (if any?) between: | We should try to establish relationship/s (if any?) between: | ||
| * groupped attributes | * groupped attributes | ||
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| FIXME | FIXME | ||
| - | ===== Attribute Markup ===== | + | ==== Attribute Markup ==== |
| see: [[hekate markup language]] | see: [[hekate markup language]] | ||
