Haskell >>= R %>% HaskellR!

• Sigrid Keydana
• bit of a contender for the max no. of career changes competition (not a Kaggle competition)
• data scientist and machine learning expert at Trivadis
• currently mostly specialising in Deep Learning
• blog: http://recurrentnull.wordpress.com, twitter: @zkajdan
• functional programming aficionada but not enough time

-- get sth from stdin and print "hello, <x>"

getLine >>= putStrLn . ("hello " ++)

# this would be it...

readline() %>% (function(name) paste0("hello ", name))

-- find the max value of a list, take its logarithm and make it negative

dostuff xs = negate . log . maximum $ xs

# this is purrr compose

dostuff <- compose(function(x) -x, log, max)

-- a function that adds 1 to its argument

plus1 = (+1)

# this would be purrr's partial

plus1 <- partial(`+`,1)

• pure, strongly typed, lazily evaluated language
• elegant code that reads just like a description of the algorithm itself
• widely used in industry (financial and trading systems, real-time applications, metaprogramming, strongly parallelized systems, web applications, cryptography … etc. etc. etc.)

• some things are very hard to do / not implemented: see State of the Haskell ecosystem (continuously updated)

  • Machine Learning
  • Data Science
  • Visualization

• … right what R is great at!

• developed by Tweag I/O
• embedded R interpreter (inline-r)
• interactive prompt for evaluating Haskell as well as R code (H)
• Jupyter notebook compatible (ihaskell-inline-r)

• no marshalling/unmarshalling of arguments (R values are pointers to SEXPRECs as in R itself)
• R capabilities provided by hosting an embedded instance of the R interpreter
• everything R happens inside the R monad
• between calls to the embedded R interpreter, state is preserved

Demo time!

• Intro to HaskellR demo
• Stock market demo