I Streamed a Stream

These are the exercises for the Stream Processing Code Jam at the 2018 YOW! Lambda Jam conference.

Sample solutions can be found in the solutions branch of this repository.

Background Information

• Workshop Slides.

  These do not have much content and serve primarily as an introduction to the exercises.

• My Streaming talk at FP-Syd.

  This workshop was based upon a talk I gave at FP-Syd on 25 October, 2017. These slides contain more content than the ones above, with examples, etc.

Understanding the exercises

Each exercise contains a README.md that you should read to gain background understanding of the tasks involved.

However, the actual details are found in the actual source files. Each exercise has its Haskell source file (within LambdaJAM/Streaming/) with detailed discussion, instructions, etc.

Why is the first exercise numbered "0"?

1. Dijkstra. QED.

2. More realistically: because if you're comfortable enough with Haskell data structures, etc. you may wish to skip this one.

   It's not like I spent any time on it...

How to run these exercises

You have the option of three build tool options:

1. stack: from the root directory, run stack build to get all dependencies, etc. built.

   You can then do stack ghci exercise0:lib, etc. to load each exercise's file.

   Note that for exercise_5, you may need to specify a filename of "exercise_5/languages.csv".

2. cabal-install: you will need to consider each exercise in isolation. For example:

   ivan LambdaJAM-Streaming-exercises $cd exercise_0/
   ivan exercise_0 $cabal sandbox init
   Writing a default package environment file to
   /home/ivan/Haskell/LambdaJAM-Streaming-exercises/exercise_0/cabal.sandbox.config
   Creating a new sandbox at
   /home/ivan/Haskell/LambdaJAM-Streaming-exercises/exercise_0/.cabal-sandbox
   ivan exercise_0 $cabal install --only-dependencies
   Resolving dependencies...
   All the requested packages are already installed:
   Use --reinstall if you want to reinstall anyway.
   ivan exercise_0 $cabal repl
   Resolving dependencies...
   Configuring exercise0-0.1.0.0...
   Preprocessing library for exercise0-0.1.0.0..
   GHCi, version 8.2.2: http://www.haskell.org/ghc/  :? for help
   Loaded GHCi configuration from /home/ivan/.ghci
   [1 of 1] Compiling LambdaJAM.Streaming.Exercise0 ( LambdaJAM/Streaming/Exercise0.hs, interpreted )
   Ok, one module loaded.
   *LambdaJAM.Streaming.Exercise0>

   (You may need to run cabal update first.)

3. cabal-install + the Nix package manager: similar to above but with no need for a sandbox:

   ivan LambdaJAM-Streaming-exercises $cd exercise_0
   ivan exercise_0 $nix-shell --command "cabal configure"
   Resolving dependencies...
   Configuring exercise0-0.1.0.0...
   ivan exercise_0 $cabal repl
   Preprocessing library for exercise0-0.1.0.0..
   GHCi, version 8.2.2: http://www.haskell.org/ghc/  :? for help
   Loaded GHCi configuration from /home/ivan/.ghci
   [1 of 1] Compiling LambdaJAM.Streaming.Exercise0 ( LambdaJAM/Streaming/Exercise0.hs, interpreted )
   Ok, one module loaded.
   *LambdaJAM.Streaming.Exercise0>