Generalizing Turtle Geometry: An Extensible Language for Vector Graphics Drawing
summary
An extensible language called Panda generalizes turtle graphics into a polymorphic DSL implemented in Haskell that generates Bézier paths and SVG-style vector graphics. It exposes four core instructions (primitive, change, reset, transform), models state changes as a monoid acting on states, and uses field polymorphism so rotation/translation code reuses across turtle, path, and vector instantiations. The prototype renders concatenated paths and superimposed SVG, demonstrates 30-circle waves and a 36-repeat closure returning the turtle to origin, and runs as a writer-style monad.
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chapters (11)
- 0:00Introduction
- 0:22What is turtle geometry
- 1:50Common patterns in extensions
- 3:18Introducing PIA language
- 5:50Demonstration of PIA
- 7:11Polymorphic PIA implementation
- 11:29Instantiating PIA for domains
- 13:38Field polymorphism in state
- 14:40Correct media monad instantiation
- 16:34Key requirements for PIA DSL
- 17:17Q&A
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