1 files changed, 95 insertions, 0 deletions
diff --git a/src/reflect/tostring_test.go b/src/reflect/tostring_test.go
new file mode 100644
index 000000000..e416fd84d
--- /dev/null
+++ b/src/reflect/tostring_test.go
@@ -0,0 +1,95 @@
+// Copyright 2009 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.
+
+// Formatting of reflection types and values for debugging.
+// Not defined as methods so they do not need to be linked into most binaries;
+// the functions are not used by the library itself, only in tests.
+
+package reflect_test
+
+import (
+	. "reflect"
+	"strconv"
+)
+
+// valueToString returns a textual representation of the reflection value val.
+// For debugging only.
+func valueToString(val Value) string {
+	var str string
+	if !val.IsValid() {
+		return "<zero Value>"
+	}
+	typ := val.Type()
+	switch val.Kind() {
+	case Int, Int8, Int16, Int32, Int64:
+		return strconv.FormatInt(val.Int(), 10)
+	case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr:
+		return strconv.FormatUint(val.Uint(), 10)
+	case Float32, Float64:
+		return strconv.FormatFloat(val.Float(), 'g', -1, 64)
+	case Complex64, Complex128:
+		c := val.Complex()
+		return strconv.FormatFloat(real(c), 'g', -1, 64) + "+" + strconv.FormatFloat(imag(c), 'g', -1, 64) + "i"
+	case String:
+		return val.String()
+	case Bool:
+		if val.Bool() {
+			return "true"
+		} else {
+			return "false"
+		}
+	case Ptr:
+		v := val
+		str = typ.String() + "("
+		if v.IsNil() {
+			str += "0"
+		} else {
+			str += "&" + valueToString(v.Elem())
+		}
+		str += ")"
+		return str
+	case Array, Slice:
+		v := val
+		str += typ.String()
+		str += "{"
+		for i := 0; i < v.Len(); i++ {
+			if i > 0 {
+				str += ", "
+			}
+			str += valueToString(v.Index(i))
+		}
+		str += "}"
+		return str
+	case Map:
+		t := typ
+		str = t.String()
+		str += "{"
+		str += "<can't iterate on maps>"
+		str += "}"
+		return str
+	case Chan:
+		str = typ.String()
+		return str
+	case Struct:
+		t := typ
+		v := val
+		str += t.String()
+		str += "{"
+		for i, n := 0, v.NumField(); i < n; i++ {
+			if i > 0 {
+				str += ", "
+			}
+			str += valueToString(v.Field(i))
+		}
+		str += "}"
+		return str
+	case Interface:
+		return typ.String() + "(" + valueToString(val.Elem()) + ")"
+	case Func:
+		v := val
+		return typ.String() + "(" + strconv.FormatUint(uint64(v.Pointer()), 10) + ")"
+	default:
+		panic("valueToString: can't print type " + typ.String())
+	}
+}