Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
Hubris
subjecting Haskell to Ruby’s iron will
Mark Wotton <mwotton@shimweasel.com>
September 8, 2009
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
I n Ruby
concise and flexible
Big web community, many libraries
Fun
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
I n Haskell
Fast (optimised native code, multicore, etc)
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
I n Haskell
Fast (optimised native code, multicore, etc)
Expressive - type systems don’t have to suck.
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
I n Haskell
Fast (optimised native code, multicore, etc)
Expressive - type systems don’t have to suck.
Provably safe at compile time
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
the slide that’s going to get me lynched
JRuby vs GHC
Program Time Memory Source Size
reverse-complement 5 1 1/4
regex-dna 7 3 1/5
binary-trees 8 7 1
k-nucleotide 10 1 1/7
pidigits 18 18 2
n-body 26 53 1
chameneos-redux 30 24 1
fasta 31 142 1
fannkuch 45 22 1/4
spectral-norm 227 56 1/3
mandelbrot 319 3 1/2
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
319 times? Really?
Haskell code written by expert hackers
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
319 times? Really?
Haskell code written by expert hackers
Longer in some cases - gone hard on optimisations even when
they blow out source code size. But...
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
319 times? Really?
Haskell code written by expert hackers
Longer in some cases - gone hard on optimisations even when
they blow out source code size. But...
319 times faster, 1/3 the memory.
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
lies, damn lies, benchmarks
Hubris
problems with Haskell
TODO, gotchas, FIXME
more lies to outrage Myles
there are approximately twelve programmers in the world who
know Haskell
Nine are working on four different compilers with extensions for
solving logic puzzles in the type system (not kidding, google
“haskell instant insanity”)
The other three are working on six different web frameworks
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
Haskell example
Hubris
wrap it in Ruby
TODO, gotchas, FIXME
Peanut butter, meet chocolate
Ruby has a heap of web frameworks, convenience libraries,
well-tested integration with javascript + CSS
Haskell is smoking fast with rock solid type safety but a tiny
community
Hubris is my bridge between the two
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
Haskell example
Hubris
wrap it in Ruby
TODO, gotchas, FIXME
lazy, statically typed, and pure
clMax l i m = maximumBy ( c o m p a r i n g snd ) ( a s s o c s a r r )
where a r r = l i s t A r r a y ( 1 , l i m )
( 0 : ( map d e p t h [ 2 . . ] ) )
s t e p x = i f even x
then d i v x 2
else 3 ∗ x + 1
d e p t h x = 1 + i f n <= l i m
then a r r ! n
e l s e depth n
where n = s t e p x
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
Haskell example
Hubris
wrap it in Ruby
TODO, gotchas, FIXME
actually using it
r e q u i r e Hubris # my f a v o u r i t e l i n e
c = C o l l a t z . new # any r u b y o b j e c t
c . i n l i n e ( h a s k e l l s t r i n g ) # from ab ove
p u t s c . clMax ( 1 0 0 0 0 0 0 )
>> 837799
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
Hubris
TODO, gotchas, FIXME
Making it less sucky
Needs to use jhc, because ghc can’t produce dynamic libs right
now (works with GHC HEAD, will be compatible with 6.12)
one-way bridge, no callbacks to Ruby
a smarter mapping layer
caching of Haskell binaries
cleanup of ruby interface
shore up support for arrays, hashes, BigInts
autoconf support to find ruby libs and includes
... lots to do
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
Hubris
TODO, gotchas, FIXME
Try it out!
install GHC and JHC
git clone git://github.com/mwotton/Hubris.git
follow the README
tell me what’s missing
patches very much welcome (thanks to Josh Price, James Britt
and Tatsuhiro Ujihisa)
Mark Wotton <mwotton@shimweasel.com> Hubris

Two cultures
Hubris
TODO, gotchas, FIXME
Learning Haskell
Learn You A Haskell: why the lucky stiff’s academic cousin
Real World Haskell: awesome, practical introduction
haskell channel on freenode
beginners@haskell.org
Mark Wotton <mwotton@shimweasel.com> Hubris