how to understand golang "non-Separator characters" at path.Match - go

Question

When I use golang's embed package, I encounter confusion about path matching. that's what * refers to?
Officially called non-Separator characters
Here: https://pkg.go.dev/path/filepath#Match
'*' matches any sequence of non-Separator characters
At first I understood non-Separator characters meant forward slashes(leading slash /), but the following example shows that this is not the case.
# dir tree
├── stubs
│   ├── hello.txt
│   └── xyz
│   └── zyx.txt
└── hello.go
# source file for hello.go
package main
import "embed"
//go:embed stubs/*
var T1 embed.FS
//go:embed stubs*
var T2 embed.FS
func main() {
s, e := T1.ReadFile("stubs/hello.txt")
fmt.Println(string(s))
fmt.Println(e)
s, e = T2.ReadFile("stubs/xyz/zyx.txt")
fmt.Println(string(s))
fmt.Println(e)
}
Then run go run hello.go will execute successfully.
This case tell me * can match /.
what does non-Separator characters mean?
Thanks for the explanation.

Answer 1

T2.ReadFile("stubs/xyz/zyx.txt") works for a different reason than you think.
The documentation for go:embed explains:
If a pattern names a directory, all files in the subtree rooted at
that directory are embedded (recursively), except that files with
names beginning with ‘.’ or ‘_’ are excluded.
https://pkg.go.dev/embed#hdr-Directives
You have declared T2 as:
//go:embed stubs*
var T2 embed.FS
The pattern stubs* matches the directory stubs, so the whole directory stubs, including all files in it (recursively) are included in the T2 filesystem.