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Discussion on how to use about goio HOT 1 OPEN

wayddmldbzz commented on July 29, 2024

Discussion on how to use

from goio.

Comments (1)

Primetalk commented on July 29, 2024

Hey, @wayddmldbzz,
Thank you for your interest in this framework. Your stream-based Java-example looks nice.
The Java DSL uses an important language feature. Stream interface approximately looks like this:

interface Stream<T> {
  <R> map(Function<T, R>)
  ...
}

Unfortunately, to my knowledge Go does not support this kind of interfaces.
The only similar feature that I was able to find was to use plain functions that can take generic parameters:

func Map[T, R](Stream[T], func(T)R)

Hence, the nice Java-style DSL seems to be infeasible in the current version of Go.

Your code looks almost right. In order to make it nicer, I would make a small refactoring:

func isEnabled(h KVBase) bool {
  return h.Enabled
}

func toKeyValuePair(h KVBase) fun.Pair[string, string] {
  return fun.NewPair(h.Key, h.Value)
}

func Foo() {
        sort.Slice(headers, func(i, j int) bool {
		return headers[i].Index < headers[j].Index
	})
        headersStream := stream.FromSlice(headers)
	enabled := stream.Filter(headersStream, isEnabled)
	keyValues := stream.Map(enabled, toKeyValuePair)
	m := make(map[string]string)
	preserveKeyValue := func(f fun.Pair[string, string]) {
		m[f.V1] = f.V2
	}
	delayedStreamExecution := stream.ForEach(keyValues, preserveKeyValue)
        _, err := io.UnsafeRunSync(delayedStreamExecution)
       ...
}