Abstract
Danvy’s functional unparsing problem (Danvy in J. Funct. Program. 8(6), 621–625, 1998) is to implement a type-safe ‘printf’ function, which converts a sequence of heterogeneous arguments to a string according to a given format. The dual problem is to implement a type-safe ‘scanf’ function, which extracts a sequence of heterogeneous arguments from a string by interpreting (Friedman and Wand in LFP, pp. 348–355, 1984 and in Essentials of Programming Languages, MIT Press, 2008) the same format as an equally heterogeneous sequence of patterns that binds zero or more variables. We derive multiple solutions to both problems (Wand in J. ACM 27(1), 164–180, 1980) from their formal specifications (Wand in Theor. Comput. Sci. 20(1), 3–32, 1982).
On one hand, our solutions show how the Hindley-Milner type system, unextended, permits accessing heterogeneous sequences with the static assurance of type safety. On the other hand, our solutions demonstrate the use of control operators (Felleisen et al. in Proceedings of the 1988 ACM Conference on Lisp and Functional Programming, pp. 52–62, ACM Press, New York, 1988; Wand in POPL 85: Conference Record of the Annual ACM Symposium on Principles of Programming Languages, vol. 16, ACM Press, New York, 1985; Meyer and Wand in Logics of Programs, Lecture Notes in Computer Science, vol. 193, pp. 219–224, Springer, Berlin, 1985) to communicate with formats as coroutines (Wand in Proceedings of the 1980 ACM Conference on Lisp and Functional Programming, vol. 12, pp. 285–299, ACM Press, New York, 1980 and Haynes et al. in LFP, pp. 293–298, 1984).
Similar content being viewed by others
References
Asai, K.: On typing delimited continuations: three new solutions to the printf problem. Higher-Order Symb. Comput. 22(3), 275–291 (2009)
Asai, K., Kameyama, Y.: Polymorphic delimited continuations. In: Shao, Z. (ed.) Proceedings of APLAS 2007: 5th Asian Symposium on Programming Languages and Systems. Lecture Notes in Computer Science, vol. 4807, pp. 239–254. Springer, Berlin (2007)
Carette, J., Kiselyov, O., Shan, C.-c.: Finally tagless, partially evaluated: tagless staged interpreters for simpler typed languages. J. Funct. Program. 19(5), 509–543 (2009)
Danvy, O.: Functional unparsing. J. Funct. Program. 8(6), 621–625 (1998)
Danvy, O., Filinski, A.: A functional abstraction of typed contexts. Tech. Rep. 89/12, DIKU, University of Copenhagen, Denmark (1989). http://www.cs.au.dk/~danvy/Papers/fatc.ps.gz
Dybvig, R.K., Peyton Jones, S.L., Sabry, A.: A monadic framework for delimited continuations. J. Funct. Program. 17(6), 687–730 (2007)
Felleisen, M., Wand, M., Friedman, D.P., Duba, B.F.: Abstract continuations: a mathematical semantics for handling full jumps. In: Proceedings of the 1988 ACM Conference on Lisp and Functional Programming, pp. 52–62. ACM Press, New York (1988)
Friedman, D.P., Wand, M.: Reification: reflection without metaphysics. In: Proceedings of the 1984 ACM Symposium on Lisp and Functional Programming, pp. 348–355. ACM Press, New York (1984). 1984
Friedman, D.P., Wand, M.: Essentials of Programming Languages, 3rd edn. MIT Press, Cambridge (2008)
Goguen, J.A., Thatcher, J.W., Wagner, E.G.: An initial algebra approach to the specification, correctness and implementation of abstract data types. In: Yeh, R.T. (ed.) Current Trends in Programming Methodology, vol. 4, pp. 80–149. Prentice-Hall, Englewood Cliffs (1978)
Gunter, C.A., Rémy, D., Riecke, J.G.: A generalization of exceptions and control in ML-like languages. In: Peyton Jones, S.L. (ed.) Functional Programming Languages and Computer Architecture: 7th Conference, pp. 12–23. ACM Press, New York (1995)
Haynes, C.T., Friedman, D.P., Wand, M.: Continuations and coroutines. In: Proceedings of the 1984 ACM Symposium on Lisp and Functional Programming, pp. 293–298. ACM Press, New York (1984)
Hinze, R.: Formatting: a class act. J. Funct. Program. 13(5), 935–944 (2003)
Hudak, P.: Building domain-specific embedded languages. ACM Comput. Surv. 28(4es), 196 (1996)
Hutton, G.: A tutorial on the universality and expressiveness of fold. J. Funct. Program. 9(4), 355–372 (1999)
Kameyama, Y., Hasegawa, M.: A sound and complete axiomatization of delimited continuations. In: ICFP 03: Proceedings of the ACM International Conference on Functional Programming, pp. 177–188. ACM Press, New York (2003)
Kamin, S.: Final data types and their specification. ACM Trans. Program. Lang. Syst. 5(1), 97–121 (1983)
Kay, M.: Syntactic processing and functional sentence perspective. In: TINLAP75: Proceedings of the 1975 Workshop on Theoretical Issues in Natural Language Processing, pp. 12–15. Association for Computational Linguistics, Stroudsburg (1975)
Kiselyov, O.: Delimited control in OCaml, abstractly and concretely: system description. In: Proc. FLOPS 2010: 10th International Symposium on Functional and Logic Programming. Lecture Notes in Computer Science, vol. 6009, pp. 304–320. Springer, Berlin (2010)
Kiselyov, O., Shan, C.-c., Sabry, A.: Delimited dynamic binding. In: ICFP 06: Proceedings of the ACM International Conference on Functional Programming, pp. 26–37. ACM Press, New York (2006)
Kohlbecker, E.E., Wand, M.: Macro-by-example: deriving syntactic transformations from their specifications. In: POPL 87: Conference Record of the Annual ACM Symposium on Principles of Programming Languages, pp. 77–84. ACM Press, New York (1987)
Masuko, M., Asai, K.: Direct implementation of shift and reset in the MinCaml compiler. In: ACM SIGPLAN Workshop on ML, pp. 49–60. ACM Press, New York (2009)
Meyer, A.R., Wand, M.: Continuation semantics in typed lambdacalculi (summary). In: Parikh, R. (ed.) Logics of Programs. Lecture Notes in Computer Science, vol. 193, pp. 219–224. Springer, Berlin (1985)
Rendel, T., Ostermann, K.: Invertible syntax descriptions: unifying parsing and pretty printing. In: Gibbons, J. (ed.) Proceedings of the 3rd ACM SIGPLAN Symposium on Haskell, pp. 1–12. ACM Press, New York (2010)
Sabry, A.: What is a purely functional language? J. Funct. Program. 8(1), 1–22 (1998)
Shieber, S.M.: A uniform architecture for parsing and generation. In: COLING88: Proceedings of the 12th International Conference on Computational Linguistics, vol. 2, pp. 614–619 (1988)
Swierstra, S.D.: Combinator parsers: a short tutorial. In: Bove, A., Barbosa, L., Pardo, A., Sousa Pinto, J. (eds.) Language Engineering and Rigorous Software Development. Lecture Notes in Computer Science, vol. 5520, pp. 252–300. Springer, Berlin (2009)
Wadler, P.L.: Deforestation: transforming programs to eliminate trees. Theor. Comput. Sci. 73(2), 231–248 (1990)
Wand, M.: Final algebra semantics and data type extensions. J. Comput. Syst. Sci. 19(1), 27–44 (1979)
Wand, M.: Continuation-based multiprocessing. In: Proceedings of the 1980 ACM Conference on Lisp and Functional Programming, pp. 19–28. ACM Press, New York (1980). Reprinted in Higher-Order Symb. Comput. 12(3), 285–299 (1999)
Wand, M.: Continuation-based program transformation strategies. J. ACM 27(1), 164–180 (1980)
Wand, M.: Deriving target code as a representation of continuation semantics. ACM Transactions on Programming Languages and Systems 4(3), 496–517 (1982)
Wand, M.: Specifications, models, and implementations of data abstractions. Theoretical Computer Science 20(1), 3–32 (1982)
Wand, M.: Embedding type structure in semantics. In: POPL 85: Conference record of the annual ACM symposium on principles of programming languages, pp. 1–6. ACM Press, New York (1985)
Xi, H., Chen, C., Chen, G.: Guarded recursive datatype constructors. In: POPL 03: Conference Record of the Annual ACM Symposium on Principles of Programming Languages, pp. 224–235. ACM Press, New York (2003)
Acknowledgements
We would like to thank Yukiyoshi Kameyama and Mitch Wand for helpful discussions, and Olivier Danvy for many comments and encouragement. Many improvements to the presentation by the anonymous reviewers are gratefully acknowledged.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Asai, K., Kiselyov, O. & Shan, Cc. Functional un|unparsing. Higher-Order Symb Comput 24, 311–340 (2011). https://doi.org/10.1007/s10990-012-9087-2
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10990-012-9087-2