Modular Synthesis of Sketches Using Models

Abstract

Abstract. One problem with the constraint-based approaches to synthesis that have become popular over the last few years is that they only scale to relatively small routines, on the order of a few dozen lines of code. This paper presents a mechanism for modular reasoning that allows us to break larger synthesis problems into small manageable pieces. The approach builds on previous work in the verification community of using high-level specifications and partially interpreted functions (we call them models) in place of more complex pieces of code in order to make the analysis modular. The main contribution of this paper is to show how to combine these techniques with the counterexample guided synthesis approaches used to efficiently solve synthesis problems. Specifically, we show two new algorithms; one to efficiently synthesize functions that use models, and another one to synthesize functions while ensuring that the behavior of the resulting function will be in the set of behaviors allowed by the model. We have implemented our approach on top of the open-source Sketch synthesis system, and we demonstrate its effectiveness on several Sketch benchmark problems.

Modeling black-box components with probabilistic synthesis

“…One of the most important developments in program synthesis is the idea of sketching [52,53]; it has been used for a wide variety of purposes including autoparallelization [23] and SQL query generation [55]. Recent technical developments include recursive tree transformations [30] and improved modularity of sketches [50]. Generally, such schemes require external sketch suggestions: Presyn automates this by constructing priors over program corpora.…”

Program synthesis with algebraic library specifications

“…Other works propose alternative library models for synthesis. Singh et al [2014] propose using manually created models, which are similar to mocks and have many of the same strengths and weaknesses. Lustig and Vardi [2013] synthesize LTL systems using libraries components specified using transducers, i.e., finite state machines with outputs.…”

SWAPPER: A framework for automatic generation of formula simplifiers based on conditional rewrite rules

“…(2) Synthesis of RHS: Swapper hard-codes a predicate and realizes the RHS synthesis problem in Sketch using the generator and minimize features ([34] [32]) of the Sketch language. Swapper uses generators to recursively define the template for RHS, and minimize to find the smallest possible RHS(x) for a fixed pred (x).…”

“…In particular, this paper will focus on the Sketch synthesis system [35]. Sketch is an open source tool which has been used in systems published in multiple top-tier conferences [19,18,32,31,12,30,36], and it includes a publicly available benchmark suite of synthesis problems from several important domains including storyboard programming [31], query extraction [12] and automated grading (Autograder) [30], sketching Java programs [18], as well as benchmarks available from the annual synthesis competition (SyGuS) [4] . In particular, Sketch has hundreds of benchmarks for Autograder problems obtained from student submissions to introductory programming assignments on the edX platform.…”