Efficient bracket abstraction
In my paper "Efficient Bracket Abstraction Using Iconic Representations for Combinators", some fundamental properties of a new uni-variate bracket abstraction algorithm employing a string representation for combinators are established. In particular, if the input term has length n, where n > 1, the algorithm is called fewer than n times to produce the abstract. Furthermore, the space required to store the abstract, in the worst case, is of the order O(n). This algorithm also has a number of features that make it worthy of further attention. When it is used to abstract a variables from an input term of length n , where n > 1, fewer than an new combinators are introduced into the abstract. However, the total size of the string representations of these combinators grows quadratically in the number of variables abstracted and the space required to store the abstract, in the worst case, is of the order O(a2n). Fortunately, a closely related single-sweep, multi-variate algorithm exists, using an array representation for combinators, which produces an abstract whose storage requirement, in the worst case, is of the order O(an).
More information about bracket abstraction algorithms is available on this website.
- Antoni Diller, "Efficient Bracket Abstraction Using Iconic Representations for Combinators", Research Report, School of Computer Science, University of Birmingham, CSR–11–05 (September 2011); a PDF version of this paper is available on this website.
© Antoni Diller (27 March 2014)