Rudimentary support for passing type parameters into generic functions #1161
Conversation
…neration. These functions provide mappings from Go entities (variables, types, functions, etc.) to JS identifiers assigned to them. This commit adds documentation comments and renames a couple of methods to better match their role.
|
/cc @paralin for additional review. |
|
With this PR 24 out of 134 typeparams test cases pass, up from 14. |
This comment was marked as outdated.
This comment was marked as outdated.
|
@paralin what exactly are you trying to build? Standard library tests seem to be passing successfully on CI and the canonical TodoMVC app builds for me as well 😕 |
|
@nevkontakte have you tried go:embed yet? |
|
I don't have any gopherjs apps that use it yet, but this seems to work for me: |
|
@nevkontakte Okay sorry - my Go install was broken, after using a from-source go 1.18.7: https://github.com/aperturerobotics/controllerbus/tree/master/example/hello-world I get this error with a more complicated package as well. Thanks for your hard work on this! |
|
@paralin maybe something has changed in reflectlite between 1.18.5 (which our CI currently tests against) and 1.18.7 you have. This kind of breakages a rare for patch-level versions, but not impossible. Could you file a separate issue for this? |
|
@nevkontakte The reflect error is gone after I fixed my Go install. Now it's the new error: |
|
@paralin that error is probably because you are trying to compile a generic type, which is not supported yet. This PR only adds some support for generic functions, and even that is incomplete :) |
Instead of generating an independent function instance for every
combination of type parameters at compile time we construct generic
function instances at runtime using "generic factory functions". Such a
factory takes type params as arguments and returns a concrete instance
of the function for the given type params (type param values are
captured by the returned function as a closure and can be used as
necessary).
Here is an abbreviated example of how a generic function is compiled and
called:
```
// Go:
func F[T any](t T) {}
f(1)
// JS:
F = function(T){ return function(t) {}; };
F($Int)(1);
```
This approach minimizes the size of the generated JS source, which is
critical for the client-side use case, at the cost of runtime
performance. See gopherjs#1013 (comment)
for the detailed description.
Note that the implementation in this commit is far from complete:
- Generic function instances are not cached.
- Generic types are not supported.
- Declaring types dependent on type parameters doesn't work correctly.
- Operators (such as `+`) do not work correctly with generic
arguments.
|
@nevkontakte Ah ok, I thought there were no generic types in that particular package (hello-world) but I guess there might be somewhere. |
Instead of generating an independent function instance for every combination of type parameters at compile time we construct generic function instances at runtime using "generic factory functions". Such a factory takes type params as arguments and returns a concrete instance of the function for the given type params (type param values are captured by the returned function as a closure and can be used as necessary).
Here is an abbreviated example of how a generic function is compiled and called:
This approach minimizes the size of the generated JS source, which is critical for the client-side use case, at the cost of runtime
performance. See #1013 (comment) for the detailed description.
Note that the implementation in this commit is far from complete:
+) do not work correctly with generic arguments.Updates #1013.