Saved in:
Bibliographic Details
Main Authors: Prinz, Jacob, Blanchette, Henry, Lampropoulos, Leonidas
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2411.16571
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917848666865664
author Prinz, Jacob
Blanchette, Henry
Lampropoulos, Leonidas
author_facet Prinz, Jacob
Blanchette, Henry
Lampropoulos, Leonidas
contents Structure editors operate directly on a program's syntactic tree structure. At first glance, this allows for the exciting possibility that such an editor could enforce correctness properties: programs could be well-formed and sometimes even well-typed by construction. Unfortunately, traditional approaches to structure editing that attempt to rigidly enforce these properties face a seemingly fundamental problem, known in the literature as viscosity. Making changes to existing programs often requires temporarily breaking program structure -- but disallowing such changes makes it difficult to edit programs! In this paper, we present a scheme for structure editing which always maintains a valid program structure without sacrificing the fluidity necessary to freely edit programs. Two key pieces help solve this puzzle: first, we develop a novel generalization of selection for tree-based structures that properly generalizes text-based selection and editing, allowing users to freely rearrange pieces of code by cutting and pasting one-hole contexts; second, we type these one-hole contexts with a category of type diffs and explore the metatheory of the system that arises for maintaining well-typedness systematically. We implement our approach as an editor called Pantograph, and we conduct a study in which we successfully taught students to program with Pantograph and compare their performance against a traditional text editor.
format Preprint
id arxiv_https___arxiv_org_abs_2411_16571
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Pantograph: A Fluid and Typed Structure Editor
Prinz, Jacob
Blanchette, Henry
Lampropoulos, Leonidas
Programming Languages
Structure editors operate directly on a program's syntactic tree structure. At first glance, this allows for the exciting possibility that such an editor could enforce correctness properties: programs could be well-formed and sometimes even well-typed by construction. Unfortunately, traditional approaches to structure editing that attempt to rigidly enforce these properties face a seemingly fundamental problem, known in the literature as viscosity. Making changes to existing programs often requires temporarily breaking program structure -- but disallowing such changes makes it difficult to edit programs! In this paper, we present a scheme for structure editing which always maintains a valid program structure without sacrificing the fluidity necessary to freely edit programs. Two key pieces help solve this puzzle: first, we develop a novel generalization of selection for tree-based structures that properly generalizes text-based selection and editing, allowing users to freely rearrange pieces of code by cutting and pasting one-hole contexts; second, we type these one-hole contexts with a category of type diffs and explore the metatheory of the system that arises for maintaining well-typedness systematically. We implement our approach as an editor called Pantograph, and we conduct a study in which we successfully taught students to program with Pantograph and compare their performance against a traditional text editor.
title Pantograph: A Fluid and Typed Structure Editor
topic Programming Languages
url https://arxiv.org/abs/2411.16571