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mirror of https://github.com/golang/go synced 2024-11-26 06:57:56 -07:00

fmt: use new reflect interface (CL 31107)

R=r
DELTA=208  (37 added, 63 deleted, 108 changed)
OCL=31111
CL=31281
This commit is contained in:
Russ Cox 2009-07-07 11:03:31 -07:00
parent 64f4e0b197
commit 0d400a7dea

View File

@ -57,6 +57,13 @@
operand. Another variant Println inserts blanks between
operands and appends a newline.
Regardless of the verb, if an operand is an interface value,
the internal concrete value is used, not the interface itself.
Thus:
var i interface{} = 23;
fmt.Printf("%v\n", i);
will print 23.
If an operand implements interface Format, that interface
can be used for fine control of formatting.
@ -191,14 +198,14 @@ func (p *pp) Write(b []byte) (ret int, err os.Error) {
return len(b), nil;
}
func (p *pp) doprintf(format string, v reflect.StructValue);
func (p *pp) doprint(v reflect.StructValue, addspace, addnewline bool);
func (p *pp) doprintf(format string, v *reflect.StructValue);
func (p *pp) doprint(v *reflect.StructValue, addspace, addnewline bool);
// These routines end in 'f' and take a format string.
// Fprintf formats according to a format specifier and writes to w.
func Fprintf(w io.Writer, format string, a ...) (n int, error os.Error) {
v := reflect.NewValue(a).(reflect.StructValue);
v := reflect.NewValue(a).(*reflect.StructValue);
p := newPrinter();
p.doprintf(format, v);
n, error = w.Write(p.buf[0:p.n]);
@ -213,7 +220,7 @@ func Printf(format string, v ...) (n int, errno os.Error) {
// Sprintf formats according to a format specifier and returns the resulting string.
func Sprintf(format string, a ...) string {
v := reflect.NewValue(a).(reflect.StructValue);
v := reflect.NewValue(a).(*reflect.StructValue);
p := newPrinter();
p.doprintf(format, v);
s := string(p.buf)[0 : p.n];
@ -225,7 +232,7 @@ func Sprintf(format string, a ...) string {
// Fprint formats using the default formats for its operands and writes to w.
// Spaces are added between operands when neither is a string.
func Fprint(w io.Writer, a ...) (n int, error os.Error) {
v := reflect.NewValue(a).(reflect.StructValue);
v := reflect.NewValue(a).(*reflect.StructValue);
p := newPrinter();
p.doprint(v, false, false);
n, error = w.Write(p.buf[0:p.n]);
@ -242,7 +249,7 @@ func Print(v ...) (n int, errno os.Error) {
// Sprint formats using the default formats for its operands and returns the resulting string.
// Spaces are added between operands when neither is a string.
func Sprint(a ...) string {
v := reflect.NewValue(a).(reflect.StructValue);
v := reflect.NewValue(a).(*reflect.StructValue);
p := newPrinter();
p.doprint(v, false, false);
s := string(p.buf)[0 : p.n];
@ -256,7 +263,7 @@ func Sprint(a ...) string {
// Fprintln formats using the default formats for its operands and writes to w.
// Spaces are always added between operands and a newline is appended.
func Fprintln(w io.Writer, a ...) (n int, error os.Error) {
v := reflect.NewValue(a).(reflect.StructValue);
v := reflect.NewValue(a).(*reflect.StructValue);
p := newPrinter();
p.doprint(v, true, true);
n, error = w.Write(p.buf[0:p.n]);
@ -273,7 +280,7 @@ func Println(v ...) (n int, errno os.Error) {
// Sprintln formats using the default formats for its operands and returns the resulting string.
// Spaces are always added between operands and a newline is appended.
func Sprintln(a ...) string {
v := reflect.NewValue(a).(reflect.StructValue);
v := reflect.NewValue(a).(*reflect.StructValue);
p := newPrinter();
p.doprint(v, true, true);
s := string(p.buf)[0 : p.n];
@ -284,11 +291,12 @@ func Sprintln(a ...) string {
// Get the i'th arg of the struct value.
// If the arg itself is an interface, return a value for
// the thing inside the interface, not the interface itself.
func getField(v reflect.StructValue, i int) reflect.Value {
func getField(v *reflect.StructValue, i int) reflect.Value {
val := v.Field(i);
if val.Kind() == reflect.InterfaceKind {
inter := val.(reflect.InterfaceValue).Get();
return reflect.NewValue(inter);
if i, ok := val.(*reflect.InterfaceValue); ok {
if inter := i.Interface(); inter != nil {
return reflect.NewValue(inter);
}
}
return val;
}
@ -296,101 +304,80 @@ func getField(v reflect.StructValue, i int) reflect.Value {
// Getters for the fields of the argument structure.
func getBool(v reflect.Value) (val bool, ok bool) {
switch v.Kind() {
case reflect.BoolKind:
return v.(reflect.BoolValue).Get(), true;
if b, ok := v.(*reflect.BoolValue); ok {
return b.Get(), true;
}
return false, false
return;
}
func getInt(v reflect.Value) (val int64, signed, ok bool) {
switch v.Kind() {
case reflect.IntKind:
return int64(v.(reflect.IntValue).Get()), true, true;
case reflect.Int8Kind:
return int64(v.(reflect.Int8Value).Get()), true, true;
case reflect.Int16Kind:
return int64(v.(reflect.Int16Value).Get()), true, true;
case reflect.Int32Kind:
return int64(v.(reflect.Int32Value).Get()), true, true;
case reflect.Int64Kind:
return int64(v.(reflect.Int64Value).Get()), true, true;
case reflect.UintKind:
return int64(v.(reflect.UintValue).Get()), false, true;
case reflect.Uint8Kind:
return int64(v.(reflect.Uint8Value).Get()), false, true;
case reflect.Uint16Kind:
return int64(v.(reflect.Uint16Value).Get()), false, true;
case reflect.Uint32Kind:
return int64(v.(reflect.Uint32Value).Get()), false, true;
case reflect.Uint64Kind:
return int64(v.(reflect.Uint64Value).Get()), false, true;
case reflect.UintptrKind:
return int64(v.(reflect.UintptrValue).Get()), false, true;
switch v := v.(type) {
case *reflect.IntValue:
return int64(v.Get()), true, true;
case *reflect.Int8Value:
return int64(v.Get()), true, true;
case *reflect.Int16Value:
return int64(v.Get()), true, true;
case *reflect.Int32Value:
return int64(v.Get()), true, true;
case *reflect.Int64Value:
return int64(v.Get()), true, true;
case *reflect.UintValue:
return int64(v.Get()), false, true;
case *reflect.Uint8Value:
return int64(v.Get()), false, true;
case *reflect.Uint16Value:
return int64(v.Get()), false, true;
case *reflect.Uint32Value:
return int64(v.Get()), false, true;
case *reflect.Uint64Value:
return int64(v.Get()), false, true;
case *reflect.UintptrValue:
return int64(v.Get()), false, true;
}
return 0, false, false;
return;
}
func getString(v reflect.Value) (val string, ok bool) {
switch v.Kind() {
case reflect.StringKind:
return v.(reflect.StringValue).Get(), true;
case reflect.ArrayKind:
if val, ok := v.Interface().([]byte); ok {
return string(val), true;
}
if v, ok := v.(*reflect.StringValue); ok {
return v.Get(), true;
}
return "", false;
if bytes, ok := v.Interface().([]byte); ok {
return string(bytes), true;
}
return;
}
func getFloat32(v reflect.Value) (val float32, ok bool) {
switch v.Kind() {
case reflect.Float32Kind:
return float32(v.(reflect.Float32Value).Get()), true;
case reflect.FloatKind:
switch v := v.(type) {
case *reflect.Float32Value:
return float32(v.Get()), true;
case *reflect.FloatValue:
if v.Type().Size()*8 == 32 {
return float32(v.(reflect.FloatValue).Get()), true;
return float32(v.Get()), true;
}
}
return 0.0, false;
return;
}
func getFloat64(v reflect.Value) (val float64, ok bool) {
switch v.Kind() {
case reflect.FloatKind:
switch v := v.(type) {
case *reflect.FloatValue:
if v.Type().Size()*8 == 64 {
return float64(v.(reflect.FloatValue).Get()), true;
return float64(v.Get()), true;
}
case reflect.Float64Kind:
return float64(v.(reflect.Float64Value).Get()), true;
case *reflect.Float64Value:
return float64(v.Get()), true;
}
return 0.0, false;
return;
}
func getPtr(v reflect.Value) (val uintptr, ok bool) {
switch v.Kind() {
case reflect.PtrKind:
return uintptr(v.(reflect.PtrValue).Get()), true;
switch v := v.(type) {
case *reflect.PtrValue:
return uintptr(v.Get()), true;
}
return 0, false;
}
func getArrayPtr(v reflect.Value) (val reflect.ArrayValue, ok bool) {
if v.Kind() == reflect.PtrKind {
v = v.(reflect.PtrValue).Sub();
if v.Kind() == reflect.ArrayKind {
return v.(reflect.ArrayValue), true;
}
}
return nil, false;
}
func getArray(v reflect.Value) (val reflect.ArrayValue, ok bool) {
switch v.Kind() {
case reflect.ArrayKind:
return v.(reflect.ArrayValue), true;
}
return nil, false;
return;
}
// Convert ASCII to integer. n is 0 (and got is false) if no number present.
@ -418,101 +405,91 @@ func (p *pp) printField(field reflect.Value) (was_string bool) {
}
}
s := "";
switch field.Kind() {
case reflect.BoolKind:
s = p.fmt.Fmt_boolean(field.(reflect.BoolValue).Get()).Str();
case reflect.IntKind, reflect.Int8Kind, reflect.Int16Kind, reflect.Int32Kind, reflect.Int64Kind:
v, signed, ok := getInt(field);
s = p.fmt.Fmt_d64(v).Str();
case reflect.UintKind, reflect.Uint8Kind, reflect.Uint16Kind, reflect.Uint32Kind, reflect.Uint64Kind:
v, signed, ok := getInt(field);
s = p.fmt.Fmt_ud64(uint64(v)).Str();
case reflect.UintptrKind:
v, signed, ok := getInt(field);
p.fmt.sharp = !p.fmt.sharp; // turn 0x on by default
s = p.fmt.Fmt_ux64(uint64(v)).Str();
case reflect.Float32Kind:
v, ok := getFloat32(field);
s = p.fmt.Fmt_g32(v).Str();
case reflect.Float64Kind:
v, ok := getFloat64(field);
s = p.fmt.Fmt_g64(v).Str();
case reflect.FloatKind:
switch f := field.(type) {
case *reflect.BoolValue:
s = p.fmt.Fmt_boolean(f.Get()).Str();
case *reflect.Float32Value:
s = p.fmt.Fmt_g32(f.Get()).Str();
case *reflect.Float64Value:
s = p.fmt.Fmt_g64(f.Get()).Str();
case *reflect.FloatValue:
if field.Type().Size()*8 == 32 {
v, ok := getFloat32(field);
s = p.fmt.Fmt_g32(v).Str();
s = p.fmt.Fmt_g32(float32(f.Get())).Str();
} else {
v, ok := getFloat64(field);
s = p.fmt.Fmt_g64(v).Str();
s = p.fmt.Fmt_g64(float64(f.Get())).Str();
}
case reflect.StringKind:
v, ok := getString(field);
s = p.fmt.Fmt_s(v).Str();
case *reflect.StringValue:
s = p.fmt.Fmt_s(f.Get()).Str();
was_string = true;
case reflect.PtrKind:
if v, ok := getPtr(field); v == 0 {
s = "<nil>"
} else {
// pointer to array? (TODO(r): holdover; delete?)
if a, ok := getArrayPtr(field); ok {
p.addstr("&[");
for i := 0; i < a.Len(); i++ {
if i > 0 {
p.addstr(" ");
}
p.printField(a.Elem(i));
}
p.addstr("]");
} else {
p.fmt.sharp = !p.fmt.sharp; // turn 0x on by default
s = p.fmt.Fmt_uX64(uint64(v)).Str();
}
case *reflect.PtrValue:
v := f.Get();
if v == 0 {
s = "<nil>";
break;
}
case reflect.ArrayKind:
if a, ok := getArray(field); ok {
p.addstr("[");
for i := 0; i < a.Len(); i++ {
if i > 0 {
p.addstr(" ");
}
p.printField(a.Elem(i));
}
p.addstr("]");
// pointer to array?
if a, ok := f.Elem().(reflect.ArrayOrSliceValue); ok {
p.addstr("&");
p.printField(a);
break;
}
case reflect.StructKind:
p.fmt.sharp = !p.fmt.sharp; // turn 0x on by default
s = p.fmt.Fmt_uX64(uint64(v)).Str();
case reflect.ArrayOrSliceValue:
p.addstr("[");
for i := 0; i < f.Len(); i++ {
if i > 0 {
p.addstr(" ");
}
p.printField(f.Elem(i));
}
p.addstr("]");
case *reflect.StructValue:
p.add('{');
v := field.(reflect.StructValue);
t := v.Type().(reflect.StructType);
v := f;
t := v.Type().(*reflect.StructType);
donames := p.fmt.plus;
p.fmt.clearflags(); // clear flags for p.printField
for i := 0; i < v.Len(); i++ {
for i := 0; i < v.NumField(); i++ {
if i > 0 {
p.add(' ')
}
if donames {
if name, typ, tag, off := t.Field(i); name != "" {
p.addstr(name);
if f := t.Field(i); f.Name != "" {
p.addstr(f.Name);
p.add('=');
}
}
p.printField(getField(v, i));
}
p.add('}');
case reflect.InterfaceKind:
value := field.(reflect.InterfaceValue).Value();
case *reflect.InterfaceValue:
value := f.Elem();
if value == nil {
s = "<nil>"
} else {
return p.printField(value);
}
case *reflect.UintptrValue:
p.fmt.sharp = !p.fmt.sharp; // turn 0x on by default
s = p.fmt.Fmt_ux64(uint64(f.Get())).Str();
default:
v, signed, ok := getInt(field);
if ok {
if signed {
s = p.fmt.Fmt_d64(v).Str();
} else {
s = p.fmt.Fmt_ud64(uint64(v)).Str();
}
break;
}
s = "?" + field.Type().String() + "?";
}
p.addstr(s);
return was_string;
}
func (p *pp) doprintf(format string, v reflect.StructValue) {
func (p *pp) doprintf(format string, v *reflect.StructValue) {
p.ensure(len(format)); // a good starting size
end := len(format) - 1;
fieldnum := 0; // we process one field per non-trivial format
@ -555,7 +532,7 @@ func (p *pp) doprintf(format string, v reflect.StructValue) {
p.add('%'); // TODO: should we bother with width & prec?
continue;
}
if fieldnum >= v.Len() { // out of operands
if fieldnum >= v.NumField() { // out of operands
p.add('%');
p.add(c);
p.addstr("(missing)");
@ -719,11 +696,11 @@ func (p *pp) doprintf(format string, v reflect.StructValue) {
}
p.addstr(s);
}
if fieldnum < v.Len() {
if fieldnum < v.NumField() {
p.addstr("?(extra ");
for ; fieldnum < v.Len(); fieldnum++ {
for ; fieldnum < v.NumField(); fieldnum++ {
p.addstr(getField(v, fieldnum).Type().String());
if fieldnum + 1 < v.Len() {
if fieldnum + 1 < v.NumField() {
p.addstr(", ");
}
}
@ -731,21 +708,18 @@ func (p *pp) doprintf(format string, v reflect.StructValue) {
}
}
func (p *pp) doprint(v reflect.StructValue, addspace, addnewline bool) {
func (p *pp) doprint(v *reflect.StructValue, addspace, addnewline bool) {
prev_string := false;
for fieldnum := 0; fieldnum < v.Len(); fieldnum++ {
for fieldnum := 0; fieldnum < v.NumField(); fieldnum++ {
// always add spaces if we're doing println
field := getField(v, fieldnum);
if fieldnum > 0 {
if addspace {
p.add(' ')
} else if field.Kind() != reflect.StringKind && !prev_string{
// if not doing println, add spaces if neither side is a string
p.add(' ')
_, is_string := field.(*reflect.StringValue);
if addspace || !is_string && !prev_string {
p.add(' ');
}
}
was_string := p.printField(field);
prev_string = was_string;
prev_string = p.printField(field);
}
if addnewline {
p.add('\n')