golang/dep

// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package paths

import "strings"

// IsStandardImportPath reports whether $GOROOT/src/path should be considered
// part of the standard distribution. For historical reasons we allow people to add
// their own code to $GOROOT instead of using $GOPATH, but we assume that
// code will start with a domain name (dot in the first element).
// This was lovingly taken from src/cmd/go/pkg.go in Go's code (isStandardImportPath).
func IsStandardImportPath(path string) bool {
    i := strings.Index(path, "/")
    if i < 0 {
        i = len(path)
    }

    return !strings.Contains(path[:i], ".")
}