strange tree

[mattn]

This is output from command lile https://github.com/lileio/lile

$ find foo
foo/.gitignore
foo/.travis.yml
foo/Dockerfile
foo/Makefile
foo/foo/cmd/root.go
foo/foo/cmd/serve.go
foo/foo/cmd/subscribe.go
foo/foo/cmd/up.go
foo/foo/main.go
foo/foo.proto
foo/server/server.go
foo/server/server_test.go
foo/subscribers/subscribers.go

.
├── server
│   ├── server.go
│   └── server_test.go
├── subscribers
│   └── subscribers.go
├── foo
│   ├── cmd
│       ├── root.go
│       ├── serve.go
│       ├── subscribe.go
│       └── up.go
│   └── main.go
├── foo.proto
├── Makefile
├── Dockerfile
├── .travis.yml
└── .gitignore

maybe this is expected?

.
├── server
│   ├── server.go
│   └── server_test.go
├── subscribers
│   └── subscribers.go
├── foo
│   ├── cmd
│   │   ├── root.go
│   │   ├── serve.go
│   │   ├── subscribe.go
│   │   └── up.go
│   └── main.go
├── foo.proto
├── Makefile
├── Dockerfile
├── .travis.yml
└── .gitignore

[xlab]

Good catch, thanks!

[mattn]

Thanks for fixing this. BTW, why you use 0x00 0xa0 for indentation?

treeprint/treeprint.go

Line 164 in 2075aa9

fmt.Fprintf(wr, "%s   ", EdgeTypeLink)

On some character-set, for example japanese, it is shown as ?.

[xlab]

It's expected to be Unicode friendly. As far as I can remember I use the same tree util uses.
Any ideas?

[mattn]

This is output on Windows. Do you want workaround fixes only on Windows?

[mattn]

One more thing. Corner string ⎿ is two cells on some locales.

[xlab]

This package will never be platform-specific, as its output is statically defined and may be parsed in logs during process mining.

The data it outputs is prevailing over the looks.

[mattn]

So you don't want fixing for east asian ambiguous widths. Right?

I don't have strong opinion about this. Just confirming how do you think. :)

[xlab]

I'm ready to fix any issue as long as it's universal for all possible platforms and locales. If we can replace the spacing char so it will work fine with Unicode and asian encodings then let's do it.

My point is that there should be no exception cases.

[mattn]

Most easy way to fix this issue is:

diff --git a/treeprint.go b/treeprint.go
index 467c87d..7412518 100644
--- a/treeprint.go
+++ b/treeprint.go
@@ -6,6 +6,9 @@ import (
 	"fmt"
 	"io"
 	"reflect"
+	"runtime"
+
+	"github.com/mattn/go-runewidth"
 )
 
 type Value interface{}
@@ -156,12 +159,25 @@ func printNodes(wr io.Writer,
 func printValues(wr io.Writer,
 	level int, levelsEnded []int, edge EdgeType, meta MetaValue, val Value) {
 
+	var edgeTypeLink, spaces string
+	if !runewidth.IsEastAsian() {
+		spaces = "   "
+		if runtime.GOOS == "windows" {
+			edgeTypeLink = string(EdgeTypeLink) + "   "
+		} else {
+			edgeTypeLink = string(EdgeTypeLink) + "   "
+		}
+	} else {
+		spaces = "       "
+		edgeTypeLink = string(EdgeTypeLink) + "     "
+	}
+
 	for i := 0; i < level; i++ {
 		if isEnded(levelsEnded, i) {
-			fmt.Fprint(wr, "    ")
+			fmt.Fprint(wr, spaces)
 			continue
 		}
-		fmt.Fprintf(wr, "%s   ", EdgeTypeLink)
+		fmt.Fprint(wr, edgeTypeLink)
 	}
 	if meta != nil {
 		fmt.Fprintf(wr, "%s [%v]  %v\n", edge, meta, val)

[mattn]

One another fix is using ASCII letters. For example + for ⎿, | for │.

[xlab]

Okay, as the output of this utility is predictable, you could hand off both transformations to the application logic which can be OS-specific.

tree := treeprint.New()
// do stuff
log.Println(applyFilter(tree.String()))

func applyFilter(str string) string {
    // uses github.com/mattn/go-runewidth
    // checks runtime.GOOS
    // replaces treeprint.EdgeTypeLink and other with mapped ASCII chars, etc
}

I will add link to this issue in README. Thanks for the solution.

[mattn]

I don't mind about fixing my apps. However, most of packages using treeprint will have to include this workaround.