Hi all,
The next meeting will be help on Wednesday January 23rd. We normally
do not meet in January, but do this year because the November meeting
failed to happen due to a power outage at our hosts Atlassian. The
talks this month will be the talks that were scheduled for November.
This month we have two talks:
Gene Taylor: Inductive Graphs in Haskell
Ben Lippmeier: Types are Calling Conventions
Abstracts below.
The RSVP is here:
https://www.meetup.com/FP-Syd/events/vcqlmpyxpblc/
https://www.meetup.com/FP-Syd/events/vcqlmpyzcbfc/
Everybody who intends to show up on the night shoud RSVP ASAP to allow our
hosts Atlassian to sort out the catering. People who said they were
going but now find that they can't should likewise update their status.
Cheers,
Erik
Inductive Graphs in Haskell
---------------------------
An approachable introduction to the Functional Graph Library in Haskell,
showing how viewing traditional problems the correct way can
lead to elegant functional solutions.
Types are Calling Conventions
-----------------------------
Functions in the lambda calculus rightly take single values as their arguments,
and return single values as their results. Functions in machine code rightly
take multiple values as their arguments (preferably in registers) and return
multiple values (preferably in registers) as their results. For a compiler writer,
dealing with this mismatch is a right headache. Arity information, which describes
how many arguments each source level function “actually” takes wafts through ones
codebase like an unpleasant odour, and after particular compiler stages subverts
ones once-loved source level type signatures into unfortunate lies. A better
approach is to embrace uncurriedness as a first class condition, and have ones
type signatures speak the truth. How to do this is explained in the paper "Types
are Calling Conventions" by Max Bolingbroke and Simon Peyton Jones, which was
(to my knowledge) thus far unimplemented. It is now implemented, and is a good
idea. I’ll relate why.
--
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Erik de Castro Lopo
http://www.mega-nerd.com/