Practical Aspects of Declarative Languages

This book constitutes the refereed proceedings of the 22nd International Symposium on Practical Aspects of Declarative Languages, PADL 2020, held in New Orleans, USA, in January 2020.

The 10 full and 4 short papers were carefully reviewed and selected from 24 submissions. The papers present original work emphasizing novel applications and implementation techniques for all forms of declarative concepts, including programming with sets, functions, logic, and constraints. The papers are organized in the following topical headings: logical engines and applications; answer set programming systems; memory and real-time in functional programming; reasoning and efficient implementation; and small languages and implementation.

Logical Engines and Applications.- Interactive Text Graph Mining with a Prolog-based Dialog Engine.- Flexible graph matching and graph edit distance using answer set programming.- On Repairing Web Services Workflows.- Answer Set Programming Systems.- AQuA: ASP-based Visual Question Answering.- Diagnosing Data Pipeline Failures Using Action Languages: A Progress Report.- VRASP: A Virtual Reality Environment for Learning Answer Set Programming.- Memory and Real-Time in Functional Programming.- On the Effects of Integrating Region-based Memory Management and Generational Garbage Collection in ML.- RTMLton: An SML runtime for real-time systems.- A Timed IO monad.- Reasoning and Efficient Implementation.- Exploiting Database Systems and Treewidth for Counting.- Whitebox Induction of Default Rules Using High-Utility Itemset Mining.- Small Languages and Implementation.- Explanations for Dynamic Programming.- A DSL for Integer Range Reasoning: Partition, Interval and Mapping Diagrams.- Variability-Aware Datalog.