Totally Live Programming with Hazel (Progress Report)
summary
Hazel is a structure editor that keeps every editor state syntactically and statically meaningful by inserting hexagonal holes for missing pieces and by running code as it’s edited via live evaluation with holes (operations evaluate up to holes, errors become runtime holes). The project has formal metatheory — an Agda proof of edit-preservation and related theorems — dozens of papers (POPL 2017 and followups) and ~60 contributors, and is classroom-tested with 200+ students showing text-editor–like productivity while avoiding parse/type gaps.
AI-written summary · about
chapters (12)
- 0:00Hazel project intro
- 1:42Motivation for live programming
- 5:33Gap problem with structure editing
- 9:05Viscosity in structure editors
- 14:57Gradual structure editing
- 16:00Live demo of Hazel editor
- 21:23Complex syntax in Hazel
- 23:28Meaningful editor states
- 24:51Student exercises in Hazel
- 27:59Research findings and use
- 29:23Future directions
- 30:28Q&A
related talks
44mHazel: A Live Functional Programming Environment with Typed Holes
07mWeaving Schematics and Code: Interactive Visual Editing for Hardware Description Languages
21mTotal Type Error Localization and Recovery with Holes
18mRestructuring Structure Editing
15mLive Programming a Live Programming Environment: An Experience Report
43mStop Writing Dead Programs
41mHedy: A Gradual programming language
14mMoldable Live Programming with Clerk