After a five year hiatus, I decided to attempt to solve the famous N queens
problem again. This time, instead of modeling the chess board using a
`[[Bool]]`, I'm using `[Integer]` where the `Integer` indicates which column has
a queen. This is a bit lighter in RAM.
I could have and should have broken this change into smaller pieces, but when I
came up for air, I had changed too much, and most of the changes are
intermingled. Oh well... this is an exciting change!
Include habits for:
- Morning
- Evening
- Payday (the 25th)
- First of the Month
- First of the Year
Since the Morning and Evening routines might be a bit noisy, I'm excluding them
from the output using a flag, `include{Morning,Evening}`, which I support in the
UI to toggle their visibility.
I made *much* more progress on this app that I expected to today, and I *think*
-- short of supporting a database and a server -- I'm close to
being *completely* finished.
Wahoo!
Instead of accepting `List (String, Int)`, accept `List Strategy` where
`Strategy` defines whether or not the string of selectors should be applied to
the element.
I'm also renaming it `class` so I can just use `Utils.class`; `tailwind` has
little to do with the function itself.
Create UI.elm to house components like `button`, which is a simple HTML button
with `focus:outline-none` applied as a `class`, which is an accessibility
feature that I don't need for this touch-screen application.
I like this pattern more than my more opinionated patterns for UI modules in Elm
where I'd define all of the arguments as a record type (i.e. kwargs).
Use the Google Fonts API to fetch a handwritten font, which gives the app a
modicum of personality. There are more "best practices" ways to do this, such
as:
- Download the font once, and include it in the bundle
- Extend the Tailwind configure to recognize the font
- Ditch the inline <style> block
But I don't need the performance benefits that the first bullet provides. And
the second two bullets are more relevant for a larger application with more than
one font. So I think in this case, the easiest solution is best.
Also:
- Use `container` and `mx-auto` to constrain content for wide screens
Created a small MVP for digitizing my weekly habits. Much more to come.
Lots of things happening:
- Copied the boilerplate to get started
- Added a brief project-level README
- Outlined my ambitions in design.md
See README and design.md for more context on this project.
I haven't updated this list since I was living in Dargow, Germany over the
summer. Now that I've settled down, and I'm situated in the London Bridge area,
I'm updating the list.
In the spirit of Marie Kondo, I'm tidying up!
TL;DR:
- Prefer .envrc `use_nix` and delete all dir-locals.nix files
- Remove ~all references to <nixpkgs>, <unstable>, <depot> and prefer
referencing each with briefcase.third_party.{pkgs,unstable,depot}
- Delete nixBufferFromShell function since I was only using that in
dir-locals.nix files
Unforeseen problem: `buildkite-agent` runs its builds in a separate directory,
so if I want the `nix-build` command to build the newly checked out code, I need
to set <briefcase> to the CWD.
Per the assignment's instructions, the `Shift n` operation should treat
the *entire keyboard* like a cycle and shift that. I was erroneously
treating *each row* like a cycle and shifting those one-by-one.
This change fixes that. In addition, it also:
- Updates README.md with expected inputs and outputs
- Updates test suite
- Adds `split` dependency to {default,shell}.nix
TL;DR:
- include a default.nix to allow users to build an named executable
- emphasize in the README that the user needs Nix to build this project
- pin nixpkgs to a specific commit and fetch it from GitHub
Per my take-home assignment's reviewer's comments, with which for the record I
agree, I should generate the character->coordinate table from my existing qwerty
keyboard definition.
The best part is: by doing this I found a bug: Notice how the original '0'
character was mapped to the Coordinate (0,0)... thus every subsequent digit
key (i.e. the first row) is off-by-one.
Using Haskell's Text.ParserCombinators.ReadP library for the first time, and I
enjoyed it thoroughly! It's nice avoiding a third-party library like MegaParsec.
Before starting my take-home assignment, the instructions advised me to create a
"Hello, world" program in the language of my choice. Since I'm choosing Haskell,
I created this example as my starter boilerplate.
Inconveniently, I do not have the cipher code that I wrote from a previous
chapter, and I'm not eager to reimplement it.
TODO
- Implement encrypt
- Implement decrypt
- Read all characters from STDIN
I was instructed to benchmark these functions, but I couldn't get the
benchmarking library to run using Nix -- although I'm *sure* it's
possible. Unfortunately the book recommends using `stack`, which I couldn't
reproduce.
I believe there are two exercises sets in the "Composing Types" chapter. Here
are *some* of my answers so far...
I'm having trouble implementing Foldable for Compose. I was able to implement a
version of it by adding the (Functor f) constraint to the instance signature,
but I think I cheated.
I will revisit these problems as well as the earlier exercises later.
Refactor the caching policy for the Memo by evicting the elements that have been
the least-recently-accessed.
Python's heapq module default to a min-heap. By storing our heap elements
as (UnixTime, a), we can guarantee that when we call heappop, we will get the
element with the lowest UnixTime value in heap (i.e. the oldest). When we call
heappush, we use (time.time(), key) and these values -- by having the largest
UnixTime, will propogate to the bottom of the min-heap.
Bound the size of the memo by creating a BoundedQueue. Whenever we add elements
to the BoundedQueue, we remove the oldest elements. We use the BoundedQueue to
control the size of our dictionary that we're using to store our key-value pairs.
After hearing from a Jane Street recruiter, I decided to dust off some of the
DS&As knowledge. I found this article online, which outlines an example problem
called "Memo":
https://blog.janestreet.com/what-a-jane-street-dev-interview-is-like/
Here's part 1 of the solution in Python.
