add a %v format to print an arbitrary value in its "println" form.
also add code to print (pointers to) arrays, through %v.
R=rsc
DELTA=108 (70 added, 33 deleted, 5 changed)
OCL=19184
CL=19192
diff --git a/src/lib/fmt/print.go b/src/lib/fmt/print.go
index 361dfc5..4bc3790 100644
--- a/src/lib/fmt/print.go
+++ b/src/lib/fmt/print.go
@@ -255,6 +255,16 @@
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;
+}
+
// Convert ASCII to integer. n is 0 (and got is false) if no number present.
func parsenum(s string, start, end int) (n int, got bool, newi int) {
@@ -277,6 +287,56 @@
return num, isnum, start;
}
+func (p *P) printField(field reflect.Value) (was_string bool) {
+ if stringer, ok := field.Interface().(String); ok {
+ p.addstr(stringer.String());
+ return false; // this value is not a string
+ }
+ s := "";
+ switch field.Kind() {
+ case reflect.BoolKind:
+ s = p.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.d64(v).str();
+ case reflect.UintKind, reflect.Uint8Kind, reflect.Uint16Kind, reflect.Uint32Kind, reflect.Uint64Kind:
+ v, signed, ok := getInt(field);
+ s = p.fmt.ud64(uint64(v)).str();
+ case reflect.FloatKind, reflect.Float32Kind, reflect.Float64Kind, reflect.Float80Kind:
+ v, ok := getFloat(field);
+ s = p.fmt.g64(v).str();
+ case reflect.StringKind:
+ v, ok := getString(field);
+ s = p.fmt.s(v).str();
+ was_string = true;
+ case reflect.PtrKind:
+ // pointer to array?
+ if v, ok := getArrayPtr(field); ok {
+ p.addstr("&[");
+ for i := 0; i < v.Len(); i++ {
+ if i > 0 {
+ p.addstr(" ");
+ }
+ p.printField(v.Elem(i));
+ }
+ p.addstr("]");
+ break;
+ }
+ v, ok := getPtr(field);
+ p.add('0');
+ p.add('x');
+ s = p.fmt.uX64(v).str();
+ case reflect.StructKind:
+ p.add('{');
+ p.doprint(field, true, false);
+ p.add('}');
+ default:
+ s = "?" + field.Type().String() + "?";
+ }
+ p.addstr(s);
+ return was_string;
+}
+
func (p *P) doprintf(format string, v reflect.StructValue) {
p.ensure(len(format)); // a good starting size
end := len(format) - 1;
@@ -310,9 +370,11 @@
}
field := v.Field(fieldnum);
fieldnum++;
- if formatter, ok := field.Interface().(Format); ok {
- formatter.Format(p, c);
- continue;
+ if c != 'T' { // don't want thing to describe itself if we're asking for its type
+ if formatter, ok := field.Interface().(Format); ok {
+ formatter.Format(p, c);
+ continue;
+ }
}
s := "";
if p.wid_ok {
@@ -414,6 +476,14 @@
goto badtype
}
+ // arbitrary value; do your best
+ case 'v':
+ p.printField(field);
+
+ // the value's type
+ case 'T':
+ s = field.Type().String();
+
default:
badtype:
s = "%" + string(c) + "(" + field.Type().String() + ")%";
@@ -437,7 +507,6 @@
for fieldnum := 0; fieldnum < v.Len(); fieldnum++ {
// always add spaces if we're doing println
field := v.Field(fieldnum);
- s := "";
if fieldnum > 0 {
if addspace {
p.add(' ')
@@ -446,40 +515,8 @@
p.add(' ')
}
}
- if stringer, ok := field.Interface().(String); ok {
- p.addstr(stringer.String());
- prev_string = false; // this value is not a string
- continue;
- }
- switch field.Kind() {
- case reflect.BoolKind:
- s = p.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.d64(v).str();
- case reflect.UintKind, reflect.Uint8Kind, reflect.Uint16Kind, reflect.Uint32Kind, reflect.Uint64Kind:
- v, signed, ok := getInt(field);
- s = p.fmt.ud64(uint64(v)).str();
- case reflect.FloatKind, reflect.Float32Kind, reflect.Float64Kind, reflect.Float80Kind:
- v, ok := getFloat(field);
- s = p.fmt.g64(v).str();
- case reflect.StringKind:
- v, ok := getString(field);
- s = p.fmt.s(v).str();
- case reflect.PtrKind:
- v, ok := getPtr(field);
- p.add('0');
- p.add('x');
- s = p.fmt.uX64(v).str();
- case reflect.StructKind:
- p.add('{');
- p.doprint(field, true, false);
- p.add('}');
- default:
- s = "?" + field.Type().String() + "?";
- }
- p.addstr(s);
- prev_string = field.Kind() == reflect.StringKind;
+ was_string := p.printField(field);
+ prev_string = was_string;
}
if addnewline {
p.add('\n')
