Why use string_tree.append() over string.append(), if the latter is faster?

[Aquabbas]

Hello Louis and the Gleam Team,

Apologies for the rant, besides the question, in advance. I just wanna express my gratitude and say thanks!

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Background

My name is Abbas and I'm a Software Engineer based in Stockholm, Sweden. I use mainly PHP and Typescript at work but I've been getting an itch for learning a new language lately.

Gleam has really caught my attention/interest, firstly due to your passion (I've listened to Hayleigh and Giacomo and their talks are amazing too!) when talking about the language and secondly I tried Gleam a bit in NeoVim and fell in love with the Dev Ex.

• The compiler and it's hints are super helpful for learning.
• The Type System feels awesome.

I'm quite new to the language (new to FP languages as well) and I'm currently going through the language tour and I'm having a blast!

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Question

I was wondering why would you use string.append() over string_tree.append()? Is there a hidden cost to using the former vs. the latter?

the LSP mentions something about StringTree running in constant time and that I should use string_tree.append() if I'm frequently joining strings, because it's faster.

I'm not sure what constant time is and what it means in practice for us developers 🤔. Is there a good article that explains this concept well that you could share? Or could you explain this concept here, if it's not too complex?

• Image 1: Shows LSP hint about string.append().
  

• Image 2: Shows LSP hint about string_tree.append().
  

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Thank you so much for creating this super fun language! I can't wait to start building stuff with it :)

[lpil]

Hello! There's documentation on when to use string tree in its module. https://hexdocs.pm/gleam_stdlib/gleam/string_tree.html#StringTree

It's always good to benchmark your code when optimising the hot-path as which is better will depend on what your code does.

[Aquabbas]

Thanks for link! :)