1 files changed, 67 insertions, 0 deletions
diff --git a/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/github.com/gopherjs/gopherjs/compiler/natives/src/strings/strings.go b/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/github.com/gopherjs/gopherjs/compiler/natives/src/strings/strings.go
new file mode 100644
index 00000000000..09b1bb59748
--- /dev/null
+++ b/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/github.com/gopherjs/gopherjs/compiler/natives/src/strings/strings.go
@@ -0,0 +1,67 @@
+// +build js
+
+package strings
+
+import (
+	"unicode/utf8"
+
+	"github.com/gopherjs/gopherjs/js"
+)
+
+func IndexByte(s string, c byte) int {
+	return js.InternalObject(s).Call("indexOf", js.Global.Get("String").Call("fromCharCode", c)).Int()
+}
+
+func Index(s, sep string) int {
+	return js.InternalObject(s).Call("indexOf", js.InternalObject(sep)).Int()
+}
+
+func LastIndex(s, sep string) int {
+	return js.InternalObject(s).Call("lastIndexOf", js.InternalObject(sep)).Int()
+}
+
+func Count(s, sep string) int {
+	n := 0
+	// special cases
+	switch {
+	case len(sep) == 0:
+		return utf8.RuneCountInString(s) + 1
+	case len(sep) > len(s):
+		return 0
+	case len(sep) == len(s):
+		if sep == s {
+			return 1
+		}
+		return 0
+	}
+
+	for {
+		pos := Index(s, sep)
+		if pos == -1 {
+			break
+		}
+		n++
+		s = s[pos+len(sep):]
+	}
+	return n
+}
+
+func (b *Builder) String() string {
+	// Upstream Builder.String relies on package unsafe. We can't do that.
+	// TODO: It's possible that the entire strings.Builder API can be implemented
+	//       more efficiently for GOARCH=js specifically (avoid using []byte, instead
+	//       use a String directly; or some JavaScript string builder API if one exists).
+	//       But this is more work, defer doing it until there's a need shown via profiling,
+	//       and there are benchmarks available (see https://github.com/golang/go/issues/18990#issuecomment-352068533).
+	return string(b.buf)
+}
+
+func (b *Builder) copyCheck() {
+	if b.addr == nil {
+		// Upstream copyCheck uses noescape, which performs unsafe.Pointer manipulation.
+		// We can't do that, so skip it. See https://github.com/golang/go/commit/484586c81a0196e42ac52f651bc56017ca454280.
+		b.addr = b
+	} else if b.addr != b {
+		panic("strings: illegal use of non-zero Builder copied by value")
+	}
+}