• pHr34kY@lemmy.world
    4·
    3 days ago

    I thought the idea of TS is that it strongly types everything so that the JS interpreter doesn’t waste all of its time trying to figure out the best way to store a variable in RAM.

    • Feyd@programming.dev
      8·
      3 days ago

      TS is compiled to JS, so the JS interpreter isn’t privy to the type information. TS is basically a robust static analysis tool

    • Colloidal@programming.dev
      5·
      3 days ago

      The code is ultimately ran in a JS interpreter. AFAIK TS transpiles into JS, there’s no TS specific interpreter. But such a huge difference is unexpected to me.

      • TCB13@lemmy.worldEnglish
        32·
        2 days ago

        Its really not, have you noticed how an enum is transpiled? you end up with a function… a lot of other things follow the same pattern.

        • FizzyOrange@programming.dev
          1·
          1 day ago

          No they don’t. Enums are actually unique in being the only Typescript feature that requires code gen, and they consider that to have been a mistake.

          In any case that’s not the cause of the difference here.

          • TCB13@lemmy.worldEnglish
            1·
            14 hours ago

            This isn’t true, there are other features that “emit code”, that includes: namespaces, decorators and some cases even async / await (when targeting ES5 or ES6).

            • FizzyOrange@programming.dev
              1·
              9 hours ago

              Ah yeah I forgot about namespaces. I don’t think they’re a popular feature.

              The other two only generate code for backwards compatibility. When targeting the latest JavaScript versions they don’t generate anything.

              Ok decorators are technically still only a proposal so they’re slightly jumping the gun there, but the point remains.