1 files changed, 234 insertions, 0 deletions
diff --git a/src/pkg/reflect/tostring.go b/src/pkg/reflect/tostring.go
new file mode 100644
index 000000000..43be4b9e8
--- /dev/null
+++ b/src/pkg/reflect/tostring.go
@@ -0,0 +1,234 @@
+// 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.
+
+// Reflection library.
+// 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
+
+import (
+	"reflect";
+	"strconv";
+)
+
+func typeToString(typ Type, expand bool) string
+func valueToString(val Value) string
+
+func doubleQuote(s string) string {
+	out := "\"";
+	for i := 0; i < len(s); i++ {
+		c := s[i];
+		switch c {
+		case '\n':
+			out += `\n`;
+		case '\t':
+			out += `\t`;
+		case '\x00':
+			out += `\x00`;
+		case '"':
+			out += `\"`;
+		case '\\':
+			out += `\\`;
+		default:
+			out += string(c);
+		}
+	}
+	out += "\"";
+	return out;
+}
+
+type hasFields interface {
+	Field(i int)	(name string, typ Type, tag string, offset int);
+	Len()	int;
+}
+
+func typeFieldsToString(t hasFields, sep string, iface bool) string {
+	var str string;
+	for i := 0; i < t.Len(); i++ {
+		str1, typ, tag, offset := t.Field(i);
+		if str1 != "" {
+			str1 += " "
+		}
+		str2 := typeToString(typ, false);
+		if iface && str2[0:4] == "func" {
+			str2 = str2[4:len(str2)]
+		}
+		str1 += str2;
+		if tag != "" {
+			str1 += " " + doubleQuote(tag);
+		}
+		if i < t.Len() - 1 {
+			str1 += sep + " ";
+		}
+		str += str1;
+	}
+	return str;
+}
+
+// typeToString returns a textual representation of typ.  The expand
+// flag specifies whether to expand the contents of type names; if false,
+// the name itself is used as the representation.
+// Meant for debugging only; typ.String() serves for most purposes.
+func typeToString(typ Type, expand bool) string {
+	var str string;
+	if name := typ.Name(); !expand && name != "" {
+		return name
+	}
+	switch(typ.Kind()) {
+	case MissingKind:
+		return "$missing$";
+	case IntKind, Int8Kind, Int16Kind, Int32Kind, Int64Kind,
+	     UintKind, Uint8Kind, Uint16Kind, Uint32Kind, Uint64Kind,
+	     FloatKind, Float32Kind, Float64Kind,
+	     StringKind,
+	     DotDotDotKind:
+		return typ.Name();
+	case PtrKind:
+		p := typ.(PtrType);
+		return "*" + typeToString(p.Sub(), false);
+	case ArrayKind:
+		a := typ.(ArrayType);
+		if a.IsSlice() {
+			str = "[]"
+		} else {
+			str = "[" + strconv.Itoa64(int64(a.Len())) +  "]"
+		}
+		return str + typeToString(a.Elem(), false);
+	case MapKind:
+		m := typ.(MapType);
+		str = "map[" + typeToString(m.Key(), false) + "]";
+		return str + typeToString(m.Elem(), false);
+	case ChanKind:
+		c := typ.(ChanType);
+		switch c.Dir() {
+		case RecvDir:
+			str = "<-chan";
+		case SendDir:
+			str = "chan<-";
+		case BothDir:
+			str = "chan";
+		default:
+			panicln("reflect.typeToString: unknown chan direction");
+		}
+		return str + typeToString(c.Elem(), false);
+	case StructKind:
+		return "struct{" + typeFieldsToString(typ.(StructType), ";", false) + "}";
+	case InterfaceKind:
+		return "interface{" + typeFieldsToString(typ.(InterfaceType), ";", true) + "}";
+	case FuncKind:
+		f := typ.(FuncType);
+		str = "func(" + typeFieldsToString(f.In(), ",", false) + ")";
+		if f.Out() != nil {
+			str += "(" + typeFieldsToString(f.Out(), ",", false) + ")";
+		}
+		return str;
+	default:
+		panicln("reflect.typeToString: can't print type ", typ.Kind());
+	}
+	return "reflect.typeToString: can't happen";
+}
+
+// TODO: want an unsigned one too
+func integer(v int64) string {
+	return strconv.Itoa64(v);
+}
+
+// valueToString returns a textual representation of the reflection value val.
+// For debugging only.
+func valueToString(val Value) string {
+	var str string;
+	typ := val.Type();
+	switch(val.Kind()) {
+	case MissingKind:
+		return "missing";
+	case IntKind:
+		return integer(int64(val.(IntValue).Get()));
+	case Int8Kind:
+		return integer(int64(val.(Int8Value).Get()));
+	case Int16Kind:
+		return integer(int64(val.(Int16Value).Get()));
+	case Int32Kind:
+		return integer(int64(val.(Int32Value).Get()));
+	case Int64Kind:
+		return integer(int64(val.(Int64Value).Get()));
+	case UintKind:
+		return integer(int64(val.(UintValue).Get()));
+	case Uint8Kind:
+		return integer(int64(val.(Uint8Value).Get()));
+	case Uint16Kind:
+		return integer(int64(val.(Uint16Value).Get()));
+	case Uint32Kind:
+		return integer(int64(val.(Uint32Value).Get()));
+	case Uint64Kind:
+		return integer(int64(val.(Uint64Value).Get()));
+	case FloatKind:
+		if strconv.FloatSize == 32 {
+			return strconv.Ftoa32(float32(val.(FloatValue).Get()), 'g', -1);
+		} else {
+			return strconv.Ftoa64(float64(val.(FloatValue).Get()), 'g', -1);
+		}
+	case Float32Kind:
+		return strconv.Ftoa32(val.(Float32Value).Get(), 'g', -1);
+	case Float64Kind:
+		return strconv.Ftoa64(val.(Float64Value).Get(), 'g', -1);
+	case StringKind:
+		return val.(StringValue).Get();
+	case BoolKind:
+		if val.(BoolValue).Get() {
+			return "true"
+		} else {
+			return "false"
+		}
+	case PtrKind:
+		v := val.(PtrValue);
+		return typeToString(typ, false) + "(" + integer(int64(uintptr(v.Get()))) + ")";
+	case ArrayKind:
+		t := typ.(ArrayType);
+		v := val.(ArrayValue);
+		str += typeToString(t, false);
+		str += "{";
+		for i := 0; i < v.Len(); i++ {
+			if i > 0 {
+				str += ", "
+			}
+			str += valueToString(v.Elem(i));
+		}
+		str += "}";
+		return str;
+	case MapKind:
+		t := typ.(MapType);
+		v := val.(MapValue);
+		str = typeToString(t, false);
+		str += "{";
+		str += "<can't iterate on maps>";
+		str += "}";
+		return str;
+	case ChanKind:
+		str = typeToString(typ, false);
+		return str;
+	case StructKind:
+		t := typ.(StructType);
+		v := val.(StructValue);
+		str += typeToString(t, false);
+		str += "{";
+		for i := 0; i < v.Len(); i++ {
+			if i > 0 {
+				str += ", "
+			}
+			str += valueToString(v.Field(i));
+		}
+		str += "}";
+		return str;
+	case InterfaceKind:
+		return "can't print interfaces yet";
+	case FuncKind:
+		v := val.(FuncValue);
+		return typeToString(typ, false) + "(" + integer(int64(uintptr(v.Get()))) + ")";
+	default:
+		panicln("reflect.valueToString: can't print type ", val.Kind());
+	}
+	return "reflect.valueToString: can't happen";
+}