Comment by throw_m239339 | Hacker News Reader

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Comment by throw_m239339 | Hacker News Reader

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throw_m239339·

> There's a reason languages like C# or Go don't have them,

Go has a quasi macro system though (go generate)

https://gradha.github.io/articles/2015/01/the-day-go-reinven...

I like the macro systems in Crystal and Haxe (reifed macros)

https://haxe.org/manual/macro-reification-expression.html

https://crystal-lang.org/reference/1.8/syntax_and_semantics/...

I think C would have benefited from such system at the AST level instead of text substitution.

Javascript is dynamic enough there is absolutely no need for Macros.

> Javascript is dynamic enough there is absolutely no need for Macros.

TypeScript macroses would be very useful for the same things codegenerators are useful: for example generating api client from swagger schema. Ofc you can do some trickery with metaprogramming, for example build and eval strings on fly and the result could be a dynamically generated function, but the point is: we want the process and the result to be typesafe and efficient, which is what is missing with hacky dynamic metaprogramming approaches.

A swagger schema looks like YAML with a finite set of types. I don't see why you'd need to use eval in that case when from one hand you already have the schema in a javascript object and the other hand a simple builder pattern would build your API directly from that schema. Absolutely no need for macros.

Generally speaking, because it would be very nice to have types without having to do offline code generation.

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