113 Matching Annotations
  1. Jun 2020
    1. What would be nice is if JavaScript had a built-in way to do what I can do in Ruby with:

      > I18n.interpolate('Hi, %{name}', name: 'Fred')
      => "Hi, Fred"

      But to be fair, I18n comes from i18n library, so JS could just as easily (and I'm sure does) have a library that does the same thing.

      Update: Actually, you can do this in plain Ruby (so why do we even need I18n.interpolate?):

      main > "Hi, %{name}" % {name: 'Fred'}
      => "Hi, Fred"
      main > ? String#%
      From: string.c (C Method):
      Owner: String
      Visibility: public
      Signature: %(arg1)
      Number of lines: 9
      Format---Uses str as a format specification, and returns the result
      of applying it to arg. If the format specification contains more than
      one substitution, then arg must be an Array or Hash
      containing the values to be substituted. See Kernel::sprintf for
      details of the format string.
         "%05d" % 123                              #=> "00123"
         "%-5s: %016x" % [ "ID", self.object_id ]  #=> "ID   : 00002b054ec93168"
         "foo = %{foo}" % { :foo => 'bar' }        #=> "foo = bar"

      I guess that built-in version is fine for simple cases. You only need to use I18n.translate if you need its more advanced features like I18n.config.missing_interpolation_argument_handler.

  2. May 2020
    1. However, distributing such Ruby apps to inexperienced end users or non-Ruby-programmer end users is problematic. If users have to install Ruby first, or if they have to use RubyGems, they can easily run into problems. Even if they already have Ruby installed, they can still run into problems, e.g. by having the wrong Ruby version installed. The point is, it's a very real problem that could harm your reputation.
    1. Programming languages These will probably expose my ignorance pretty nicely.

      When to use different programming languages (advice from an Amazon employee):

      • Java - enterprise applications
      • C# - Microsoft's spin on Java (useful in the Microsoft's ecosystem)
      • Ruby - when speed is more important then legibility or debugging
      • Python - same as Ruby but also for ML/AI (don't forget to use type hinting to make life a little saner)
      • Go/Rust - fresh web service where latency and performance were more important than community/library support
      • Haskell/Erlang - for very elegant/mathematical functional approach without a lot of business logic
      • Clojure - in situation when you love Lisp (?)
      • Kotlin/Scala - languages compiling to JVM bytecode (preferable over Clojure). Kotlin works with Java and has great IntelliJ support
      • C - classes of applications (operating systems, language design, low-level programming and hardware)
      • C++ - robotics, video games and high frequency trading where the performance gains from no garbage collection make it preferable to Java
      • PHP/Hack - testing server changes without rebuilding. PHP is banned at Amazon due to security reasons, but its successor, Hack, runs a lot of Facebook and Slack's backends
  3. Apr 2020
    1. The method name is generated by replacing spaces with underscores. The result does not need to be a valid Ruby identifier though, the name may contain punctuation characters etc. That's because in Ruby technically any string may be a method name. This may require use of define_method and send calls to function properly, but formally there's little restriction on the name.
    1. But where is the helper method defined? What’s its visibility? Can I put it in a module? Can I use inheritance? Who can call it? Can I call super from the extracted method? If so, where does super go?
    1. minitest doesn't reinvent anything that ruby already provides, like: classes, modules, inheritance, methods. This means you only have to learn ruby to use minitest and all of your regular OO practices like extract-method refactorings still apply.
    1. This situation usually arises from external constraints not design choices such as my example with Sequel. My point is that assigning a value to a constant is allowed by Ruby in certain scopes and not others. It used to be up to the developer to choose wisely when to perform the assignment. Ruby changed on this. Not for everyone's good.
    1. The handler can be a method or a Proc object passed to the :with option. You can also use a block directly instead of an explicit Proc object.

      Example of: letting you either pass a proc (as a keyword arg in this case) or as a block.

  4. Mar 2020
    1. Ruby's current handling of Dates and Times is all over the map. We have Date, Time, DateTime, ParseDate, and more, not to mention all the other common extensions running around out there. Ruby needs an improved class that incorporates them all.
    1. Methods must be tested both via a Lemon unit test and as a QED demo. The Lemon unit tests are for testing a method in detail whereas the QED demos are for demonstrating usage.
    1. prepend_message
    2. To be just a bit polemic, your first instinct was not to do that. And you probably wouldn't think of that in your unit tests either (the holy grail of dynamic langs). So someday it would blow up at runtime, and THEN you'd add that safeguard.
    3. As many would guess: ... catch StandardError => e raise $! ... raises the same error referenced by $!, the same as simply calling: ... catch StandardError => e raise ... but probably not for the reasons one might think. In this case, the call to raise is NOT just raising the object in $!...it raises the result of $!.exception(nil), which in this case happens to be $!.
    1. The pattern below has become exceptionally useful for me (pun intended). It's clean, can be easily modularized, and the errors are expressive. Within my class I define new errors that inherit from StandardError, and I raise them with messages (for example, the object associated with the error).
    1. The popular question in my company these days is “Rails or WordPress?”, but I will probably touch upon the broader questions of “MVC or CMS?” and “Ruby or PHP?”, so you can often substitute “Rails” for “MVC framework” in the article.
  5. Feb 2020
    1. Returns an indication of the number of arguments accepted by a method. Returns a nonnegative integer for methods that take a fixed number of arguments. For Ruby methods that take a variable number of arguments, returns -n-1, where n is the number of required arguments. Keyword arguments will be considered as a single additional argument, that argument being mandatory if any keyword argument is mandatory. For methods written in C, returns -1 if the call takes a variable number of arguments.

      What they fail to mention is that apparently the arity is always -1 if the method is available dynamically (due to respond_to_missing?).

  6. Jan 2020
    1. I've often wished for some standard variable to use for blocks and such. Like some people here, I had considered it. Usually I use _ but I know that means "unused" to many/most programmers. I like the % option that Clojure has.

  7. Dec 2019
  8. Nov 2019
    1. Example of someone else defining a file that simply requires another file because this is the one that gem (?) or bundler (?) looks for when your gem is named activerecord-pg_enum

  9. Oct 2019
  10. Sep 2019
  11. Aug 2019
  12. Feb 2019
  13. Jan 2016
    1. require 'active_record/connection_adapters/postgis_adapter/railtie'

      The following worked better in my setup:

      require 'active_record/connection_adapters/postgis/railtie'
    1. with another instance as its receiver

      An instance can call private methods of another instance of the same class.

  14. Nov 2015
    1. まぶた)

      Testing a highlight on Ruby text.

      Highlight is meant to wrap this image: kanji

      Highlight is also meant to include the super-script hiragana characters: まぶた

      Actual highlight includes the hiragana characters "まぶた" as well as ")"

  15. Jul 2015
  16. May 2015
    1. Just to focus on the differences between lambdas and Procs, a lambda acts more like a real method. What does that mean?

      Apparently it means a lambda is less ($@(#$ insane.

    2. When you create your own function to accept procs, the guts need to change a little bit because you'll need to use #call instead of yield inside (because which proc would yield run if you had more than one?).

      Too much special!! Why the special cases? Just so that one can type yield instead of invoking a function and naming the argument?

    3. Use that block of code (now called a Proc) as an input to a function by prepending it with an apersand &

      Oh, Ruby. This is entirely too confusing. Why is the ampersand required to signify that something is passed as a block, especially given that it has a type (Proc)? What does it mean if the ampersand isn't used?