go-streams
An experiment which attempts to create streams similar to what is available in Java now that we have generics.
Should I use this library?
No.
Should I use a different library that does this?
No.
Examples
Filter
Filter doesn’t even look that bad to be frank.
func TestFilter(t *testing.T) {
slice := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
result := streams.New(slice).
Filter(onlyEven).
Collect()
require.Equal(t, []int{2, 4, 6, 8, 10}, result)
}
func onlyEven(v int) bool {
return v%2 == 0
}
Map and filter
Map and filter looks terrible as methods can’t be parametrized with extra type parameters which forced me to use a top level function.
func TestConvolutedExample(t *testing.T) {
slice := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
result := streams.Map(
streams.New(slice).Filter(onlyEven),
intToString,
).
Filter(onlyOneByte).
Collect()
require.Equal(t, []string{"2", "4", "6", "8"}, result)
}
func onlyEven(v int) bool {
return v%2 == 0
}
func onlyOneByte(v string) bool {
return len(v) == 1
}
func intToString(v int) string {
return strconv.Itoa(v)
}
Slow?
Yes.
goos: linux
goarch: amd64
pkg: github.com/boreq/go-streams
cpu: AMD Ryzen 7 3700X 8-Core Processor
BenchmarkFilterStream
BenchmarkFilterStream-16 4389160 312.2 ns/op
goos: linux
goarch: amd64
pkg: github.com/boreq/go-streams
cpu: AMD Ryzen 7 3700X 8-Core Processor
BenchmarkFilterLoop
BenchmarkFilterLoop-16 6928596 193.4 ns/op
