Next meeting on Wednesday January 23rd

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Erik de Castro Lopo

Jan 14, 2019, 10:33:46 PM1/14/19
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:

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.


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.

Erik de Castro Lopo

Erik de Castro Lopo

Jan 14, 2019, 10:38:58 PM1/14/19
Erik de Castro Lopo wrote:

> The next meeting will be help on Wednesday January 23rd.

Also doors open 6pm, meeting proper starts at 6:30pm.


Jamie Georgeson

Jan 23, 2019, 12:32:52 AM1/23/19
Hey folks,

A graduate on-boarding program has overtaken our usual room at Atlassian for tonight, so we're going to set up in the lunch room.

Same floor, same building - it's just the big room you see when you come straight out of the elevator on level 6; you can't miss it.

We'll do our best to have people around to direct you.


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