EcoSearch: A Constant-Delay Best-First Search Algorithm for Program Synthesis

TL;DR

EcoSearch is a novel best-first search algorithm for program synthesis that guarantees constant delay between outputs, leading to significant speedups over previous methods in classic domains.

Contribution

EcoSearch introduces the first constant-delay best-first search algorithm for program synthesis, improving efficiency by maintaining a fixed compute interval between outputs.

Findings

EcoSearch outperforms previous algorithms on two classic domains.

The constant-delay property enables predictable and improved speed.

EcoSearch reduces the search space exploration time.

Abstract

Many approaches to program synthesis perform a combinatorial search within a large space of programs to find one that satisfies a given specification. To tame the search space blowup, previous works introduced probabilistic and neural approaches to guide this combinatorial search by inducing heuristic cost functions. Best-first search algorithms ensure to search in the exact order induced by the cost function, significantly reducing the portion of the program space to be explored. We present a new best-first search algorithm called EcoSearch, which is the first constant-delay algorithm for pre-generation cost function: the amount of compute required between outputting two programs is constant, and in particular does not increase over time. This key property yields important speedups: we observe that EcoSearch outperforms its predecessors on two classic domains.