Re: [sca-assembly] Interface compatibility with type inheritences

[Mike Edwards <mike_edwards@uk.ibm.com>]

Raymond,

First tell me how all this looks in
WSDL and XSD.


Yours,  Mike.

Strategist - Emerging Technologies, SCA & SDO.
Co Chair OASIS SCA Assembly TC.
IBM Hursley Park, Mail Point 146, Winchester, SO21 2JN, Great Britain.
Phone & FAX: +44-1962-818014    Mobile: +44-7802-467431  
Email:  mike_edwards@uk.ibm.com

From:	Raymond Feng <rfeng@us.ibm.com>
To:	sca-assembly@lists.oasis-open.org
Date:	19/02/2010 20:24
Subject:	[sca-assembly] Interface compatibility with type inheritences

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Hi, 

The spec currently has this statement for the operation compatibility:

2512 3. compatibility for individual
operations of the interfaces A and B is defined as
2513 compatibility of the signature,
i.e., the operation name, the input types, and the
2514 output types are the same

Many programming languages support inheritance, for example, Java and XML.
Requiring the input types and output types to be the same seems to be too
restrictive. For example, say Apple is a sub type of Fruit, then we could
have two operations as follows: 

1) Fruit[] findSameColor(Apple apple) ; // Find all fruits that has the
same color as the given apple 
2) Apple[] findSameColor(Fruit fruit); // Return all apples that has the
same color as the given fruit 

Any requests made via operation 1 can be handled by a service that supports
2 and any response (including fault/exception) produced by operation 2
can be handled by the caller of operation 1. 

Can we just a reference typed by 1 and wire it to a service implementing
2? 

Thanks, 
Raymond

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Raymond Feng
Senior Software Engineer, Apache Tuscany PMC Member & Committer 
IBM Bay Area Lab, 1001 E Hillsdale Blvd, Suite 400, Foster City, CA 94404,
USA
E-mail: rfeng@us.ibm.com,
Notes: Raymond Feng/Burlingame/IBM, Tel: 650-645-8117,
T/L: 367-8117
Personal Web Site: www.enjoyjava.com
Apache Tuscany: http://tuscany.apache.org
Co-author of Tuscany In Action: http://www.manning.com/laws

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