Is there anything similar to Class.forName("string") in Java or "string".constantize in Ruby for Go?

[daniel....@gmail.com]

Hi,

Basically the idea is to find something similar to Java's Class.forName("some_type") or Ruby's "some_type".constantize in order to get a type constant at runtime. I know I could implement this behaviour with a switch/case statement, but for the purposes of the project I am working on, it would be a bit repetitive.

A more detailed example of what I am trying to accomplish here: http://play.golang.org/p/sJyCSf8anE

Thanks!

[Javier Asensio]

I presume you can't (I'm fairly new to go), I didn't find anything similar in the reflect api. Anyway, from my point of view that would too "magical" for my taste, how about making a registry of the available services that you can actually instantiate? I think it would be easier to code/test than using reflection, which always adds an extra layer of complexity

http://play.golang.org/p/72NoDDLZR9

cheers,

Javi

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[Jesse McNelis]

On Thu, Sep 26, 2013 at 8:24 PM, <daniel....@gmail.com> wrote:

Hi,

Basically the idea is to find something similar to Java's Class.forName("some_type") or Ruby's "some_type".constantize in order to get a type constant at runtime. I know I could implement this behaviour with a switch/case statement, but for the purposes of the project I am working on, it would be a bit repetitive.

Types that you don't explicitly reference in code aren't included in the binary at runtime and thus can't be referred to. If getting a type from a string was possible it would prevent the compiler from doing this dead code elimination which would make statically linked binaries huge.

If you want a to convert a string to a type at runtime you'll need to have a map[string]reflect.Type that you explicitly fill.

 

A more detailed example of what I am trying to accomplish here: http://play.golang.org/p/sJyCSf8anE

Thanks!

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[daniel....@gmail.com]

Thanks for clarifying it. I went with Javi's suggestion.

[George McBay]

Also keep in mind that Go is very good at parsing itself, so it isn't too difficult to write a program that you can point at an arbitrary package directory (or set of such directories) to automatically generate a name->Type map for you and just make that part of your build process.