Functional Logic Programming

• Introduce the functional logic programming paradigm
• Present its main features and advantages for program development 
• Study the basis in which its computational models are based
• Overview actual functional logic languages
• Explain the programming environments currently available for these languages and implementation techniques 
• Develop practical examples by using such programming systems
  

Contents

1. Computational Models
1. Term Rewriting Systems [BN98,Vad02]
• Terms, substitutions, equations
• Term rewriting systems
  
• Termination and confluence
• Conditional rewriting
2. Lazy Rewriting Strategies [BN98,Vad02]
• Orthogonal Rewriting Systems
• Needed redexes
• Inductively sequential systems (ISSs)
• Needed rewriting strategy (NR) for ISSs
3. The rewriting logic CRWL  [Vad02,GHLR99]
   
• C-convergency conditions
• Indeterminisim with call-time choice
• The rewriting calculus CRWL
4. Goal resolution by narrowing [Vad02,MH94]
• Goal resolution in equational semantics
• Unrestriced narrowing
• Conditional narrowing
5. Lazy narrowing strategies  [Vad02,GHLR99,MO98,AEH00]
   

• Goal resolution with a c-convergency semantics
• Lazy narrowing by goal transformation calculus
• The needed narrowing strategy (NN) for ISSs
• Possible extensions of the NN strategy

2. The TOY programming language
1. Language features
• Non deterministic functions
• Constraints
• Higher-order patterns
• Finite failure
2. Programming Tools: Declarative debugging, etc.
3. Implementation techniques

3. The Curry programming language
1. Computational model: NN + residuation [Han97a]
2. New language features: encapsulated search, monadic IO [CurryTR]
3. PAKCS [PAKCS00]
   
   • Executing Curry programs: Curry2Prolog, Curry2Java and TasteCurry
   • The module system
     
   • Curry Doc: A documentation tool [Han02]
4. Applications
• Distributed programming [Han99]
• Object-Oriented extension [HHN00]
• Web programming [Han01]
• Design patterns [AH02]
  
5. Programming tools:
• A partial evaluator for Curry  [AHV02]
• A profiling tool [AV02]

References

[AHV02] E. Albert, M. Hanus, G. Vidal. A practical partial evaluation scheme for multi-paradigm declarative languages. 
	Journal of Functional and Logic Programming, 2002(1):1-34, March 2002.

[AV02] 	E. Albert and Germán Vidal. Symbolic profiling for multi-paradigm declarative languages. 
	In Logic-Based Program Synthesis and Transformation (Proc. of LOPSTR'01), pages 148--167. Springer LNCS 2372, 2002.

[Ant92]	S.Antoy. Definitional Trees. 
	Proc.ALP'92, Springer LNCS 632, pp. 143--157, 1992.

[AEH00]	S. Antoy, R. Echahed, and M. Hanus. A Needed Narrowing Strategy. 
	Journal of the ACM, Vol. 47 (4), pp. 776--822, July 2000.

[AH02]	S. Antoy and M. Hanus. Functional logic design patterns.
	In  Proc. of the 6th International Symposium on Functional and Logic Programming (FLOPS 2002). Springer LNCS 2441, 2002.

[BN98]	F. Baader and T. Nipkow.  Term Rewriting and All That.
	Cambridge University Press, 1998.

[CL99b]	R. Caballero and F.J. López-Fraguas.  A Functional Logic Perspective of Parsing. 
	Proc. FLOPS'99, Springer LNCS 1722, pp. 85--99, 1999.

[GHLR99]J.C. González-Moreno, M.T. Hortalá-González, F.J. López-Fraguas, and M. Rodríguez-Artalejo.  An Approach to Declarative Programming based on a Rewriting Logic.
	Journal of Logic Programming 40, pp. 47--87, 1999.

[GHLR01]J.C. González-Moreno, M.T. Hortalá-González, F.J. López-Fraguas, and M. Rodríguez-Artalejo. Polymorphic Types in Functional Logic Programming. 
	Journal of Functional and Logic Programming, Vol. 2001/S01 (special issue of selected papers contributed to FLOPS'99), pp. 1--71, 2001. 

[Han94]	M. Hanus.  The Integration of Functions into Logic Programming: From Theory to Practice. 
	Journal of Logic Programming 19&20, pp. 583--628, 1994.

[Han97a]M. Hanus.  A Unified Computation Model for Functional and Logic Programming. 
	Proc. POPL'97, ACM Press, pp. 80--93, 1997.

[Han97b]M. Hanus.  Teaching Functional and Logic Programming with a Single Computation Model. 
	Proc. PLILP'97, Springer LNCS 1292, pp. 335--350, 1997.

[Han99]	M. Hanus. Distributed programming in a multi-paradigm declarative language.
	In  Proc. of the International Conference on Principles and Practice of Declarative Programming (PPDP'99), pages 376--395. Springer LNCS 1702, 1999.

[CurryTR]M. Hanus (ed.). Curry: An Integrated Functional Logic Language.
	Available at: http://www.informatik.uni-kiel.de/ mh/curry/, 1999.

[Han01]	M. Hanus. High-level server side web scripting in curry.
	In  Proc. of the Third International Symposium on Practical Aspects of Declarative Languages (PADL'01). Springer LNCS 1990, 2001.

[Han02]	M. Hanus. Currydoc: A documentation tool for declarative programs.
	In  Proc. of the 11th International Workshop on Functional and (Constraint) Logic Programming (WFLP 2002), pages 225--228, Grado (Italy), 2002. Research Report UDMI/18/2002/RR, Universit`a degli Studi di Udine.

[PAKCS00]M. Hanus, S. Antoy, J. Koj, R. Sadre, and F. Steiner. PAKCS 1.2: The Portland Aachen Kiel Curry System User Manual.
 	Technical report, University of Kiel, Germany, 2000.

[HHN00]	M. Hanus, F. Huch, and P. Niederau. An object-oriented extension of the declarative multi-paradigm language curry.
	In  Proc. of the 12th International Workshop on Implementation of Functional Languages (IFL 2000), pages 89--106. Springer LNCS 2011, 2001.

[HLM98]	M. Hanus, S. Lucas, and A. Middeldorp.  Strongly sequential and inductively sequential term rewriting systems. 
	Information Processing Letters, Vol. 67 (1), pp. 1--8, 1998.

[LLR93]	R. Loogen, F.J. López-Fraguas, and M. Rodríguez-Artalejo. A Demand Driven Computation  Strategy  for  Lazy  Narrowing.
	Proc.  PLILP'93,  Springer LNCS 714, pp. 184--200, 1993.

[LS02]	F.J. López-Fraguas and J. Sánchez-Hernández. A Proof Theoretic Approach to Failure in Functional Logic Programming. 
	To appear in  Theory and Practice of Logic Programming.

[Mid97]	A. Middeldorp.  Call by Need Computations to Root-Stable Form. 
	Proc. POPL'97, ACM Press, pp. 94--105, 1997.

[MH94]	A. Middeldorp and E. Hamoen.  Completeness Results for Basic Narrowing. 
	Applicable Algebra in Engineering, Communications and Computing 5, pp. 213--253, 1994.

[MO98]	A. Middeldorp and S. Okui.  A Deterministic Lazy Narrowing Calculus. 
	Journal of Symbolic Computation 25(6), pp. 733--757, 1998. Preliminary version appeared in Proc. 1st Fuji Int. Workshop on Functional and Logic Programming,  World Scientific, pp. 104--118, 1995.

[Rod01]	M. Rodríguez-Artalejo.  Functional and Constraint Logic Programming. 
	Constraints in Computational Logics, International Summer School CCL'99, Revised Lectures. Springer LNCS 2002, Chapter 5, pp. 202--270, 2001.

[Vad02]	R. del Vado Vírseda.  Estrategias de Estrechamiento Perezoso. 
	Trabajo de Investigación, Programa de Doctorado ``Sistemas Informáticos y Programaci'on'' (segundo período), DSIP UCM, Septiembre de 2002.