-- File:	Transfer_Mapper.cdl
-- Created:	Fri Nov  4 10:47:55 1994
-- Author:	Christian CAILLET
--		<cky@anion>
---Copyright:	 Matra Datavision 1994


generic class Mapper from Transfer
    (TheKey    as  any;
     TheHasher as  any;
     TheInfo   as  any)
        inherits Finder

    ---Purpose : a Mapper defines a Finder for a specific input class
    --           its definition includes the value of the Key to be mapped,
    --           and the HashCoder associated to the class of the Key
    --           
    --           TheKey defines the class to be keyed
    --           TheHasher is the associated Hasher
    --           TheInfo   is an additionnal class which helps to provide
    --             informations on the value (template : see DataInfo)

uses CString

is

    Create (akey : any TheKey) returns mutable Mapper;
    ---Purpose : Creates a Mapper with a Value. This Value can then not be
    --           changed. It is used by the Hasher to compute the HashCode,
    --           which will then be stored for an immediate reading.

    Value (me) returns any TheKey  is static;
    ---Purpose : Returns the contained value
    ---C++ : return const &

    Equates (me; other : Finder) returns Boolean;
    ---Purpose : Specific testof equallity : defined as False if <other> has
    --           not the same true Type, else contents are compared (by
    --           C++ operator ==)

    ValueType    (me) returns Type  is redefined;
    ---Purpose : Returns the Type of the Value. By default, returns the
    --           DynamicType of <me>, but can be redefined

    ValueTypeName (me) returns CString  is redefined;
    ---Purpose : Returns the name of the Type of the Value. Default is name
    --           of ValueType, unless it is for a non-handled object

fields

    theval  : TheKey;

end Mapper;