alexandremcosta

What a trumpet taught me about code

My best friend is a musician, I’m a coder. Professionally and also as our favorite hobbies. He uses instruments to create songs, I use languages to create apps. We often fall into parallels between both worlds, but yesterday’s conversation went somewhere new.

He told me he bought a trumpet. No previous experience, never touched one before. I asked if he was going to take classes or figure it out himself. He laughed… already figuring it out himself, obviously. So he walked me through it.

First he figured out the mechanics. How much the sound changes when he presses the first valve, the second, the third. He knows a little trombone, so he could pick up the different mouth positions, each one produces a different note in a different range.

Then came the first AHA-moment.

alexandremcosta

-- =============================================================================
-- A single-file Neovim configuration inspired by AstroNvim's UX conventions
-- with a minimal, readable setup.
-- =============================================================================
--
-- REQUIREMENTS:
--   Neovim >= 0.11   (uses vim.lsp.config/enable API and LspProgress event)
--   git              (lazy.nvim bootstrap and gitsigns)
--   make             (telescope-fzf-native build step)
--   A Nerd Font      (icons in neo-tree, lualine, bufferline, dashboard)

alexandremcosta

Deadlock detected,
The system is infected.
Zombie processes
Haunt orphaned guests.

Abort transactions,
While we break the loop.
Don’t crash the node,
It’s a dependency soup.

alexandremcosta

# List Comprehensions
squares = [x**2 for x in range(10)]
even_squares = [x**2 for x in range(10) if x % 2 == 0]

# Dictionary Comprehensions
squared_dict = {x: x**2 for x in range(10)}

# Lambda Functions
add = lambda a, b: a + b

alexandremcosta

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all

alexandremcosta

Reward system

A company is planning a way to reward customers for inviting their friends.
They're planning a reward system that will give a customer points for each confirmed invitation they played a part into.
The definition of a confirmed invitation is one where another invitation's invitee invited someone.

The inviter gets (1/2)^k points for each confirmed invitation, where k is the level of the invitation:

• level 0 (people directly invited) yields 1 point
• level 1 (people invited by someone invited by the original customer) gives 1/2 points
• level 2 invitations (people invited by someone on level 1) awards 1/4 points and so on

alexandremcosta

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• Git Handbook

alexandremcosta

defmodule Downloader do
  @moduledoc"""
  Download streams of bytes from URLs.
  Useful to transfer large files with low RAM usage.
  
  ## Example with `ExAWS.S3.upload/3`
  
  ```elixir
  url
  |> Downloader.stream_body!()

alexandremcosta

defmodule MigrateRedis do
  require Logger

  @from [host: "127.0.0.1", port: 6379]
  @to [host: "127.0.0.1", port: 6379]

  def migrate(from \\ @from, to \\ @to) do
    {:ok, from} = Redix.start_link(from)
    {:ok, to} = Redix.start_link(to)

alexandremcosta

class Weather::Interpolation
  def initialize(x, y, z, xi, yi)
    @x, @y, @z, @xi, @yi = x, y, z, xi, yi
  end

  def calc
    # if any location closer than 10km, return this location
    close_location = distances.index {|d| d < 10}
    close_location ? @z[close_location] : interpolation
  end