UNIVERSITY OF HERTFORDSHIRE

    COMPUTER SCIENCE RESEARCH COLLOQUIUM


		presents

          "Type Error Reporting in 
        a Single-assignment Language 
        with Homomorphic Overloading"

		speaker:

               James Hansen
       Computer Science Department
       University of Hertfordshire


	 1 October 2003 (Wednesday)

	  Lecture Theatre E351 
	    Hatfield Campus
		3 - 4 pm


 Coffee/tea and biscuits will be available.


      Everyone is Welcome to Attend


Abstract:
                                                                                
An overview of the concepts and motivations behind ASTL (Array 
Stream Transformer Language) is given.  The language uses a 
type system with overloading and atomic subtyping, where all 
overloadings of an operator are homomorphic under type coercions.  
Concequently, type inference is done on the basis of a general 
constraint set expansion, rather than type unification 
characteristic of a polymorphic Hindley-Milner system. 
This makes type-error reporting a particularly challenging problem.  
We present here our original solution to it.
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Hertfordshire Computer Science Research Colloquium Abstracts
On-line: http://homepages.feis.herts.ac.uk/~nehaniv/colloq/