Keith Schacht's Weblog: Ruby

Bundler can be configured to auto install

2025-04-28T15:35:23+00:00

No more pulling down changes to a project and realizing I need to run `bundle install`. Run this command once on a dev machine and it'll auto install whenever new gems are needed: `bundle config --global auto_install true`.

Tags: Ruby

Ruby's clamp method reduces conditionals

2025-02-24T15:19:46+00:00

You can constrain a variable to be within a range using clamp:

5.clamp(1, 10)  # => 5
-3.clamp(1, 10) # => 1
15.clamp(1, 10) # => 10

Tags: Ruby

Regex within string square brackets

2025-02-24T15:16:30+00:00

I've always known that Ruby supports ranges within a string's square brackets. So in addition to the simple `name[4]` I can do `name[2..4]` and `name[2...]` and `name[-1]`. But I just learned you can put regex in the square brackets for more dynamic substring selectors: `"me+abc123@email.com"[/.+\+(.+)@(.+)/, 2]` will give you the subdomain of the email address. It even works with named capture groups! `"123.45"[/(?<dollars>\d+)\.(?<centers>\d+)/, :dollars]` will give you the dollars. The article has a few other notable examples.

via

Tags: Ruby

Ruby Sorbet is too verbose, can the syntax be improved?

2024-10-29T20:36:38+00:00

Awhile back when I was ramping up on Typescript, I was leaning into the benefits of types. In the Ruby world, Sorbet is the most common way to add types so I gave that a shot. In the end, I ripped it out. I spent more time wrangling type checking then the time it spent catching bugs, and one of the issues was the verbose syntax. But recently I came up with a novel solution to this problem. First, here is the verbose syntax — you end up declaring all your arguments twice:

sig { params(name: T.untyped, nickname: String).returns(Integer) }
def greet(name, nickname)
  puts "Hello, #{name}! Your nickname: #{nickname}"
  name.length
end

It may not seem like a big deal, but every time you change the name of an argument or change the order, you have to do it in two places. Recently I had an idea: could we do it in one line if we used Ruby to redefine how methods are defined? I got this syntax working and threw it up on a gist:

# Two positional arguments. The first, name, is untyped.
# The second, nickname, must be a String

df :greet,  :name, nickname: [String], returns: Integer do
  puts "Hello, #{name}! Your nickname: #{nickname}"
  name.length
end

Here is a gist. It supports positional and named arguments. I got it working with runtime and static analysis. I don't plan to take this experiment any further right now, but maybe it's useful to someone.

Tags: Ruby

Ruby can chain methods and right-assign

2024-10-29T20:23:35+00:00

I just learned that ruby supports re-writing this:

total = plus_shipping(with_taxes(subtotal(items)))

As:

subtotal(items).then { |subtotal| with_taxes(subtotal) }.then { |total| plus_shipping(total) } => total

from davetron

Tags: Ruby