-- File:	Units.cdl
-- Created:	Mon Jun 22 18:23:44 1992
-- Author:	Gilles DEBARBOUILLE
--		<gde@phobox>
-- Modified     Wed Apr  2 14:10:05 1997 by Gerard GRAS    
--		Add FirstQuantity access methods
-- Modified     Mon Apr  7 16:52:40 1997 by Patrick BOSINCO
--		Add Dimensions access methods
---Copyright:	 Matra Datavision 1992


package Units 

	---Purpose: This  package provides all the  facilities  to create
	--          and question a dictionary of  units,  and also  to
	--          manipulate measurements which are real values with
	--          units.

uses

    TCollection,
    TColStd

is
            
    class Dimensions;
    
    class Unit;
    
    class UtsSequence instantiates
          Sequence from TCollection (Unit from Units);
    class UnitsSequence instantiates 
    	  HSequence from TCollection(Unit from Units, UtsSequence);
    
    private class ShiftedUnit;

    class Token ;
    
    class ShiftedToken ;
    
    class TksSequence instantiates
           Sequence from TCollection (Token from Units);
    class TokensSequence instantiates 
    	   HSequence from TCollection(Token from Units, TksSequence);
    
    class Quantity;
    
    class QtsSequence instantiates
          Sequence from TCollection (Quantity from Units);
    class QuantitiesSequence instantiates 
    	  HSequence from TCollection(Quantity from Units, QtsSequence);
    
    class UnitsDictionary;
    
    class UnitsSystem;
    
    class Explorer;
    
    private class Sentence;
    
    private class MathSentence;
    
    private class UnitSentence;
    
    class Lexicon;
    
    private class UnitsLexicon;
    
    class Measurement;
    
    exception NoSuchUnit inherits NoSuchObject from Standard;
    exception NoSuchType inherits NoSuchObject from Standard;
    
    UnitsFile(afile : CString);
    
    ---Level: Public
    
    ---Purpose: Defines the location of the file containing all the 
    --          information useful in creating the dictionary of all 
    --          the units known to the system.
    
    LexiconFile(afile : CString);
    
    ---Level: Public
    
    ---Purpose: Defines the location of the file containing the lexicon 
    --          useful in manipulating composite units.
    
    DictionaryOfUnits(amode : Boolean = Standard_False) returns UnitsDictionary from Units;
    
    ---Level: Advanced
    
    ---Purpose: Returns a unique instance of the dictionary of units.
    --          If <amode> is True, then it forces the recomputation of 
    --          the dictionary of units.
    
    Quantity(aquantity : CString from Standard) returns Quantity from Units;
    
    ---Level: Advanced
    
    ---Purpose: Returns a unique quantity instance corresponding to <aquantity>.

    FirstQuantity(aunit : CString from Standard) returns CString from Standard;

    ---Level: Advanced

    ---Purpose: Returns the first quantity string founded from the unit <aUnit>.

    LexiconUnits(amode : Boolean = Standard_True) returns Lexicon from Units;
    
    ---Level: Internal
    
    ---Purpose: Returns a unique instance of the Units_Lexicon.
    --          If <amode> is True, it forces the recomputation of 
    --          the dictionary of units, and by consequence the 
    --          completion of the Units_Lexicon.
    
    LexiconFormula returns Lexicon from Units;
    
    ---Level: Internal 

    ---Purpose: Return a unique instance of LexiconFormula.
    
    NullDimensions returns Dimensions from Units;
    
    ---Level: Internal
    
    ---Purpose: Returns always the same instance of Dimensions.
    
    Convert(avalue : Real ; afirstunit , asecondunit : CString) returns Real;
    
    ---Level: Public
    
    ---Purpose: Converts <avalue> expressed in <afirstunit> into the <asecondunit>.
            
    ToSI(aData: Real from Standard; aUnit: CString from Standard) returns Real from Standard;

    ToSI(aData: Real from Standard; aUnit: CString from Standard;
         aDim : out Dimensions from Units) returns Real from Standard;

    FromSI(aData: Real from Standard; aUnit: CString from Standard) returns Real from Standard;

    FromSI(aData: Real from Standard; aUnit: CString from Standard;
           aDim : out Dimensions from Units ) returns Real from Standard;

    Dimensions(aType : CString from Standard)
    returns Dimensions from Units
    raises NoSuchObject from Standard;
    ---Level: Public
    ---Purpose: return the dimension associated to the Type

end Units;