-- File:	Units_Sentence.cdl
-- Created:	Mon Jun 22 17:29:32 1992
-- Author:	Gilles DEBARBOUILLE
--		<gde@phobox>
---Copyright:	 Matra Datavision 1992


private class Sentence from Units 

	---Purpose: This class describes all the methods to create and
	--          compute an expression contained in a string.

uses

    Token          from Units,
    TokensSequence from Units,
    Lexicon        from Units

--raises

is

    Create(alexicon : Lexicon from Units ; astring : CString)
    
    ---Level: Internal 
    
    ---Purpose: Creates and  returns  a   Sentence, by  analyzing  the
    --          string <astring> with the lexicon <alexicon>.
    
    returns Sentence from Units;
    
    SetConstants(me : in out)
    
    ---Level: Internal 
    
    ---Purpose: For each constant encountered, sets the value.
    
    is static;
    
    Sequence(me) returns any TokensSequence from Units
    
    ---Level: Internal 
    
    ---C++: inline
    
    ---Purpose: Returns <thesequenceoftokens>.
    
    is static;
    
    Sequence(me : in out ; asequenceoftokens : any TokensSequence from Units)
    
    ---Level: Internal 
    
    ---C++: inline
    
    ---Purpose: Sets the field <thesequenceoftokens> to <asequenceoftokens>.
    
    is static;
    
    Evaluate(me : in out)returns mutable Token from Units
    
    ---Level: Internal 
    
    ---Purpose: Computes and  returns in a   token the result  of  the
    --          expression.
    
    is static;
    
    IsDone(me) returns Boolean from Standard
    ---Level: Internal 
    ---C++: inline
    ---Purpose: Return True if number of created tokens > 0
    --          (i.e creation of sentence is succesfull)
    is static;

    Dump(me)
    
    ---Level: Internal 
    
    ---C++: inline
    
    ---Purpose: Useful for debugging.
    
    is static;

fields

    thesequenceoftokens : TokensSequence from Units;

end Sentence;