Yampa

Yampa is a domain-specific embedded language for the programming of hybrid (discrete and continuous time) systems using the concepts of Functional Reactive Programming (FRP). Yampa is structured using Arrows, which greatly reduce the chance of introducing space- and time-leaks into reactive, time-varying systems.

Yampa was originally developed by the Yale Haskell Group based on the original idea of Conal Elliott's Fran.

Hackage: Yampa

Introduction

• Henrik Nilsson - A Brief Introduction to Functional Reactive Programming and Yampa
• Henrik Nilsson - ITU-FRP2010
  • ITU-FRP2010 01
  • ITU-FRP2010 02
  • ITU-FRP2010 03
  • ITU-FRP2010 04
  • ITU-FRP2010 05
  • ITU-FRP2010 06
  • ITU-FRP2010 07
• Paul Hudak - Yampa, Arrows, and Robots
• Yampa tutorials by Gerold Meisinger
  • Learning Yampa and Functional Reactive Programming (archived)
  • Running primitive signal functions in Yampa (archived)
  • Yampa/SDL program stub (archived)
  • Dataflow diagram of Yampa reactimate (archived)
  • Activity diagram of Yampa reactimate (archived)
  • Diagrams of Yampa switches
• Yampa book - Tutorial series for BearRiver Yampa
• library reference sheet: ps, pdf
• Videos
  • Safe Functional Reactive Programming through Dependent Types
  • Causal Commutative Arrows and Their Optimization
  • Euterpea: From signals to symphonies

Primitive signal functions

(download original Image:Yampa signal functions.svg‎)

Switches

Reddit - How to read Yampa diagram?

• switch
• rSwitch
• kSwitch
• pSwitchB
• pSwitch
• rpSwitchB
• rpSwitch

Each switch comes in two different flavors:

1. immediate: switch to the new behaviour immediately and also calculate the return value based on the new behaviour.
2. delayed: return the value based on the old behaviour, but use the new behaviour afterwards. To use delayed switch prefix the switching functions with the letter 'd', f.e. 'drpSwitchB'.

Reactimation

• reactimate
• Game engine

External Links

• Yampa-Users mailing list - Yampa-related comments, questions, discussions, and announcements. You can also send bug reports to yampa-bugs@cs.yale.edu.
• #yampa - This is Yampa IRC Channel, please refer to Getting there on how to join the channel.
• Yampy Cube - a live coding presentation with Yampa by Konstantin Zudov at Helsinki FRP Meetup May 6, 2015. (Source code on Github)
• George Giorgidze created YampaSynth, a modular music synthesizer written in Haskell and using Yampa.
• Hai (Paul) Liu papers and slides
• Blog about Yampa - introduction tutorials and diagrams
• Demonstrating a Time Leak in Arrowized FRP (Web archive)
  • answer
• An overview of Yampa video clips on YouTube

Known users

search Hackage

• YampaSynth - is a software synthesizer implemented in Haskell using Yampa. It contains a framework of sound generating and sound shaping modules (e.g. oscillator, amplifier, mixer, envelope generator, filter, etc.) and example applications.
• Frag; a simple Quake 3 clone, using a very early version of Yampa called arrowized functional reactive programming (AFRP)
• SpaceInvaders; a video game, demonstrating the usage of Yampa
• cuboid; a small puzzle game
• Haskelloids; asteroids clone
• Nettle - Programming Network Routers
• Euterpea - computer music development (also uses CCA)
• YFrob; robot simulation
• Haskanoid A breakout-like videogame with SDL graphics and sound that can optionally be controlled with a Wiimote or a Kinect.
• Magic Cookies! An iOS/Android board game implemented in Haskell using Yampa and SDL2.

search Github

• Hamball
• YampaShooter

Known forks

• Yampa-core
  • related discussion
• Animas
  • code cleanup
• Functional Reactive Virtual Reality
  • FRVR source code
  • DIVE project