How to be correct, lazy and efficient ?

TL;DR

This paper introduces Lambdix, a lazy Lisp interpreter that demonstrates semantic correctness can align with efficiency, challenging common assumptions about Lisp implementation difficulties.

Contribution

It presents Lambdix, a novel lazy Lisp interpreter that addresses semantic issues and improves efficiency compared to previous models.

Findings

Lambdix avoids common semantic difficulties of Lisp.

Lambdix is more efficient for lazy evaluation.

Comparative tables show Lambdix's superior performance.

Abstract

This paper is an introduction to Lambdix, a lazy Lisp interpreter implemented at the Research Laboratory of Paris XI University (Laboratoire de Recherche en Informatique, Orsay). Lambdix was devised in the course of an investigation into the relationship between the semantics of programming languages and their implementation; it was used to demonstrate that in the Lisp domain, semantic correctness is consistent with efficiency, contrary to what has often been claimed. The first part of the paper is an overview of well-known semantic difficulties encountered by Lisp as well as an informal presentation of Lambdix; it is shown that the difficulties which Lisp encouters do not arise in Lambdix. The second part is about efficiency in implementation models. It explains why Lambdix is better suited for lazy evaluation than previous models. The section ends by giving comparative execution time tables.