7 OCaml Gotchas

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• chshersh.com :: 7 OCaml Gotchas

Comments

[yami-no-ryuu]

1. Labelled and Optional Arguments There's another gotcha, way worse. Partial application of such a function is hell on earth :( (ie type inference support is half there)

[Yawar Amin]

Alternatively, you can use the local open syntax:...Book.(book.words) >= 50000

You can also prefix the field name with its module: book.Book.words >= 50_000 ;-)

[Kakadu]

Gotcha 3 is actually a warning.
Also, deciphering severity from the icons looks complicated.

[Dmitrii Kovanikov]

Gotcha 3 is actually a warning.

Indeed, it's a warning. Still, I found this behaviour surprising, and decided to describe it in my blog post 😌

Also, deciphering severity from the icons looks complicated.

I don't think it's critical for the blog post understanding. Just a little extra from me to make the text less boring.

My idea was:

• 🍹- chill, not really important
• ⚠️ - warning, you may have potential problems
• 💀 - something really dangerous can happen

[Kakadu]

In this case gotcha 6 has severity too high

[Juneyoung Lee]

For gotcha 2 you can use begin..end. Something like this:

match .. with
| ... -> begin match .. with ... end

[Cyril]

You can also directly match the reason part in Pending. Not always practical, but in your example, I might have written:

let show_status status =
  match status with
  | Cancelled -> "Cancelled"
  | Done -> "Done"
  | Pending Waiting -> "Pending: Waiting"
  | Pending Validating -> "Pending: Validating"