neon mica
Just a sample of how external types are defined. If I have a pre-existing erlang library/repo, what do I need to do to get it to function/bind correctly?
I understand the syntax, but is there some configuration I need to set in the gleam toml file, or is it literally just getting the src files and referencing their relative path?
wooden barn
External types are “gleam doesnt know anything about this”. When you define an external type its representation is totally arbitrary because gleam code cant inspect or construct that type.
Its not external in the sense that the type is defined somewhere else and must be imported its external in the sense that the type represents values external to gleam
neon mica
It's more a question of "how."
If I have a library of types and functions, what is the process to actually define the dependency/binding in gleam?
wooden barn
There isnt one
Its a question that doesn’t make sense
A library of external functions makes sense, but types dont
neon mica
so when I do this:
@external(erlang, "<what is this supposed to be?", "foo")
pub fn do_foo(input: Int) -> Nil
The erlang module
wooden barn
Depends where its coming from? If its erlang stdlib or your own ffi then no, if its a package on hex then yes
neon mica
To complete the circle, I have an erlang library that I want to bind its types and functions to gleam.
https://github.com/hwatkins/erlguten
So when I do the external definitions, do I drag the erlang files with the gleam?
and then reference them by their relative path?
Its a touch confusing. In the example JS bindings are by path and the Erlang is done by absolute references to the std_lib implementations of erlang
wooden barn
Modules are global in erlang
So yes its “absolute path” in the sense that you simply refer to modules according to how they are organised the same way you do for importing gleam modules
https://hex.pm/packages/erlguten its published on hex, add it with gleam add and then its just eg_pdf
@external(erlang, “eg_pdf”, “line_cap”) for example
neon mica
Got it! I’ll try it out.
glass tinsel
`@external(erlang, “eg_pdf”, “line_cap”)` for example
Hehe
wooden barn
Sorry for terseness, on mobile ^.^
glass tinsel
@wooden barn might wanna edit that