Abstract

This paper describes a method for eliminating a certain class of space leaks in lazy functional languages. A program that space leaks consumes more memory than would be expected. This may lead to longer execution time, or that the program unnecessarily runs out of memory. It has been known for a long time that functions returning tuples may give rise to space leaks. Hughes [Hug83] has shown that some programs must leak memory, if a sequential 1 evaluator is used. Several researchers have tried to solve this problem, with varying approaches, by introducing the necessary parallelism. Some of them modify the garbage collector, or use special operators to parallelize the programs explicitly. The approach used here is to use pattern bindings in definitions, which are available in most functional languages, to control the parallelism. No modification of the garbage collector or special operators are needed. The method has been implemented in the Chalmers LML/HBC compiler [AJ93, AJ89]. 1 I...

Citations

515	The Implementation of Functional Programming Languages - Jones - 1987
216	Report on the programming language Haskell, a non-strict, purely functional language - Hudak, Jones, et al. - 1992
77	Fudgets---a graphical user interface in a lazy functional language - Carlsson, Hallgren - 1993
62	Compiling Lazy Functional Languages - Johnsson - 1987
57	The design and implementation of programming languages - Hughes - 1983
49	Heap profiling of lazy functional programs - Runciman, Wakelin - 1993
41	Compiling Lazy Functional Languages, Part II - Augustsson - 1987
19	Fixing some space leaks with a garbage collector - Wadler - 1987
12	Lazy ML User's Manual. Programming Methodology Group - Augustsson, Johnsson - 1993