Test not passing

[ww9]

Hi, not sure if I'm doing something wrong but the test isn't passing for me :(

$ go test
--- FAIL: TestMultiType (0.00s)
    intersort_test.go:131: sorted map should contain "<nil> 0xc00005c940 0xc00005c948"
    intersort_test.go:131: sorted map should contain "1 2 3"
    intersort_test.go:131: sorted map should contain "a b c"
    intersort_test.go:131: sorted map should contain "false true"
    intersort_test.go:131: sorted map should contain "{0 1} {1 0}"
    intersort_test.go:131: sorted map should contain "[0 1] [1 0]"
FAIL
exit status 1
FAIL    github.com/ww9/intersort        0.334s

$ go version
go version go1.12 windows/amd64

[lukechampine]

There's a bug in Go 1.12 that prevents it from sorting these multi-type slices properly. See golang/go#30398

If you use the internal/fmtsort package from tip it should pass.

[ww9]

I'll wait for the next release.
Thanks for the quick response!

[lukechampine]

You can get it working by changing a single line in the stdlib. Open $GOROOT/src/internal/fmtsort/sort.go and apply this patch:

@@ -167,7 +167,7 @@ func compare(aVal, bVal reflect.Value) int {
		if c, ok := nilCompare(aVal, bVal); ok {
			return c
		}
-		c := compare(reflect.ValueOf(aType), reflect.ValueOf(bType))
+		c := compare(reflect.ValueOf(aVal.Elem().Type()), reflect.ValueOf(bVal.Elem().Type()))
		if c != 0 {
			return c
		}

The test should then pass.

[ww9]

Indeed it fixed! And I learned something amazing in the process:

Go standard library code is recompiled every time if need be. It's not just a large binary .so or .dll file that you need to manually recompile after every change. So just altering that one line you told me and issuing another go test worked! Somehow Go scanned its entire stdlib source-code for changes, compiled everything including intersort and run the code all within 335 milliseconds on my old machine.

$ go test
PASS
ok      github.com/ww9/intersort        0.335s

This is amazing, it feels like I'm coding an interpreted language, not a compiled one!

Thank you for your attention!

[ww9]

I knew that Go compilation was fast and I know there's a lot of caching in the process that makes this faster, including filesystem level cache provided by SO. But still, this gives me pascal/TCC speed tier vibes.

[ww9]

My zealotry notwithstanding, I'll take the liberty to re-open this issue so it can help others trying to play with this meme sort. At least until next release of Go supports it. I'll take no offense (and why would I) if you chose to close it. Thanks

[lukechampine]

Indeed, Go is pretty amazing! :)

I agree, let's leave this open until the fix makes it into a release.

[lukechampine]

Go 1.12.1 was released today, including my fix. So tests should now pass if you are running the latest Go release. :) I will mention this in the README.

[ww9]

Thanks!