From: Rob Pike <r@golang.org>
Date: Fri, 24 Oct 2008 23:33:29 +0000 (-0700)
Subject: add printf to fmt.
X-Git-Tag: weekly.2009-11-06~2895
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=418b97c67013c892d88443949ed913ff96baf25e;p=gostls13.git

add printf to fmt.
uses reflection to determine arguments.
for now, the arguments must be provided as a struct; the compiler
will soon do the packaging automatically for "..." parameters.

R=rsc
DELTA=1436  (909 added, 520 deleted, 7 changed)
OCL=17823
CL=17831
---

diff --git a/src/lib/fmt/Makefile b/src/lib/fmt/Makefile
index 70ea703f19..64ca60c91f 100644
--- a/src/lib/fmt/Makefile
+++ b/src/lib/fmt/Makefile
@@ -3,7 +3,7 @@
 # license that can be found in the LICENSE file.
 
 # DO NOT EDIT.  Automatically generated by gobuild.
-# gobuild -m fmt fmt.go
+# gobuild -m fmt format.go print.go
 O=6
 GC=$(O)g
 CC=$(O)c -w
@@ -31,11 +31,17 @@ clean:
 
 
 O1=\
-	fmt.$O\
+	format.$O\
 
-$(PKG): a1
+O2=\
+	print.$O\
+
+$(PKG): a1 a2
 a1:	$(O1)
 	$(AR) grc $(PKG) $(O1)
+a2:	$(O2)
+	$(AR) grc $(PKG) $(O2)
 
 $(O1): nuke
+$(O2): a1
 
diff --git a/src/lib/fmt/fmt.go b/src/lib/fmt/format.go
similarity index 100%
rename from src/lib/fmt/fmt.go
rename to src/lib/fmt/format.go
diff --git a/src/lib/fmt/print.go b/src/lib/fmt/print.go
new file mode 100644
index 0000000000..db42c1e0d5
--- /dev/null
+++ b/src/lib/fmt/print.go
@@ -0,0 +1,387 @@
+// 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.
+
+package fmt
+
+import (
+	"fmt";
+	"reflect";
+	"os";
+)
+
+const Runeself = 0x80
+const AllocSize = 32
+
+export type P struct {
+	n	int;
+	buf	*[]byte;
+	fmt	*Fmt;
+}
+
+export func Printer() *P {
+	p := new(P);
+	p.fmt = fmt.New();
+	return p;
+}
+
+func (p *P) ensure(n int) {
+	if p.buf == nil || len(p.buf) < n {
+		newn := AllocSize;
+		if p.buf != nil {
+			newn += len(p.buf);
+		}
+		if newn < n {
+			newn = n + AllocSize
+		}
+		b := new([]byte, newn);
+		for i := 0; i < p.n; i++ {
+			b[i] = p.buf[i];
+		}
+		p.buf = b;
+	}
+}
+
+func (p *P) addstr(s string) {
+	n := len(s);
+	p.ensure(p.n + n);
+	for i := 0; i < n; i++ {
+		p.buf[p.n] = s[i];
+		p.n++;
+	}
+}
+
+func (p *P) addbytes(b *[]byte, start, end int) {
+	p.ensure(p.n + end-start);
+	for i := start; i < end; i++ {
+		p.buf[p.n] = b[i];
+		p.n++;
+	}
+}
+
+func (p *P) add(c int) {
+	p.ensure(p.n + 1);
+	if c < Runeself {
+		p.buf[p.n] = byte(c);
+		p.n++;
+	} else {
+		p.addstr(string(c));
+	}
+}
+
+func (p *P) reset() {
+	p.n = 0;
+}
+
+export type Writer interface {
+	Write(b *[]byte) (ret int, err *os.Error);
+}
+
+func (p *P) doprintf(format string, v reflect.StructValue);
+func (p *P) doprint(v reflect.StructValue, addspace bool);
+
+// These routines end in 'f' and take a format string.
+
+func (p *P) fprintf(w Writer, format string, a reflect.Empty) (n int, error *os.Error) {
+	v := reflect.NewValue(a).(reflect.PtrValue).Sub().(reflect.StructValue);
+	p.doprintf(format, v);
+	n, error = w.Write(p.buf[0:p.n]);
+	p.reset();
+	return n, error;
+}
+
+func (p *P) printf(format string, v reflect.Empty) (n int, errno *os.Error) {
+	n, errno = p.fprintf(os.Stdout, format, v);
+	return n, errno;
+}
+
+func (p *P) sprintf(format string, v reflect.Empty) string {
+	p.doprintf(format, reflect.NewValue(v).(reflect.StructValue));
+	s := string(p.buf)[0 : p.n];
+	p.reset();
+	return s;
+}
+
+// These routines do not take a format string and add spaces only
+// when the operand on neither side is a string.
+
+func (p *P) fprint(w Writer, a reflect.Empty) (n int, error *os.Error) {
+	v := reflect.NewValue(a).(reflect.PtrValue).Sub().(reflect.StructValue);
+	p.doprint(v, false);
+	n, error = w.Write(p.buf[0:p.n]);
+	p.reset();
+	return n, error;
+}
+
+func (p *P) print(v reflect.Empty) (n int, errno *os.Error) {
+	n, errno = p.fprint(os.Stdout, v);
+	return n, errno;
+}
+
+func (p *P) sprint(v reflect.Empty) string {
+	p.doprint(reflect.NewValue(v).(reflect.StructValue), false);
+	s := string(p.buf)[0 : p.n];
+	p.reset();
+	return s;
+}
+
+// These routines end in 'ln', do not take a format string,
+// always add spaces between operands, and add a newline
+// after the last operand.
+
+func (p *P) fprintln(w Writer, a reflect.Empty) (n int, error *os.Error) {
+	v := reflect.NewValue(a).(reflect.PtrValue).Sub().(reflect.StructValue);
+	p.doprint(v, true);
+	n, error = w.Write(p.buf[0:p.n]);
+	p.reset();
+	return n, error;
+}
+
+func (p *P) println(v reflect.Empty) (n int, errno *os.Error) {
+	n, errno = p.fprintln(os.Stdout, v);
+	return n, errno;
+}
+
+func (p *P) sprintln(v reflect.Empty) string {
+	p.doprint(reflect.NewValue(v).(reflect.StructValue), true);
+	s := string(p.buf)[0 : p.n];
+	p.reset();
+	return s;
+}
+
+// Getters for the fields of the argument structure.
+
+func getInt(v reflect.Value) (val int64, signed, ok bool) {
+	switch v.Kind() {
+	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.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;
+	}
+	return 0, false, false;
+}
+
+func getString(v reflect.Value) (val string, ok bool) {
+	switch v.Kind() {
+	case reflect.StringKind:
+		return v.(reflect.StringValue).Get(), true;
+	}
+	return "", false;
+}
+
+func getFloat(v reflect.Value) (val float64, ok bool) {
+	switch v.Kind() {
+	case reflect.Float32Kind:
+		return float64(v.(reflect.Float32Value).Get()), true;
+	case reflect.Float64Kind:
+		return float64(v.(reflect.Float32Value).Get()), true;
+	case reflect.Float80Kind:
+		break;	// TODO: what to do here?
+	}
+	return 0.0, false;
+}
+
+func getPtr(v reflect.Value) (val uint64, ok bool) {
+	switch v.Kind() {
+	case reflect.PtrKind:
+		return v.(reflect.PtrValue).Get(), true;
+	}
+	return 0, false;
+}
+
+// Convert ASCII to integer.
+
+func parsenum(s string, start, end int) (n int, got bool, newi int) {
+	if start >= end {
+		return 0, false, end
+	}
+	if s[start] == '-' {
+		a, b, c := parsenum(s, start+1, end);
+		if b {
+			return -a, b, c;
+		}
+	}
+	isnum := false;
+	num := 0;
+	for '0' <= s[start] && s[start] <= '9' {
+		num = num*10 + int(s[start] - '0');
+		start++;
+		isnum = true;
+	}
+	return num, isnum, start;
+}
+
+func (p *P) 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
+	for i := 0; i <= end;  {
+		c, w := sys.stringtorune(format, i);
+		if c != '%' || i == end {
+			p.add(c);
+			i += w;
+			continue;
+		}
+		var got bool;
+		// saw % - do we have %20 (width)?
+		w, got, i = parsenum(format, i+1, end);
+		if got {
+			p.fmt.w(w);
+		}
+		// do we have %.20 (precision)?
+		if i < end && format[i] == '.' {
+			w, got, i = parsenum(format, i+1, end);
+			if got {
+				p.fmt.p(w);
+			}
+		}
+		c, w = sys.stringtorune(format, i);
+		i += w;
+		// percent is special - absorbs no operand
+		if c == '%' {
+			p.add('%');	// TODO: should we bother with width & prec?
+			continue;
+		}
+		if fieldnum >= v.Len() {	// out of operands
+			p.addstr("???");
+			continue;
+		}
+		field := v.Field(fieldnum);
+		fieldnum++;
+		s := "";
+		switch c {
+			// int
+			case 'b':
+				if v, signed, ok := getInt(field); ok {
+					s = p.fmt.B(v).str()	// always unsigned
+				} else {
+					s = "%b%"
+				}
+			case 'd':
+				if v, signed, ok := getInt(field); ok {
+					if signed {
+						s = p.fmt.D(v).str()
+					} else {
+						s = p.fmt.uD(v).str()
+					}
+				} else {
+					s = "%d%"
+				}
+			case 'o':
+				if v, signed, ok := getInt(field); ok {
+					if signed {
+						s = p.fmt.O(v).str()
+					} else {
+						s = p.fmt.uO(v).str()
+					}
+				} else {
+					s= "%o%"
+				}
+			case 'x':
+				if v, signed, ok := getInt(field); ok {
+					if signed {
+						s = p.fmt.X(v).str()
+					} else {
+						s = p.fmt.uX(v).str()
+					}
+				} else {
+					s = "%x%"
+				}
+
+			// float
+			case 'e':
+				if v, ok := getFloat(field); ok {
+					s = p.fmt.E(v).str()
+				} else {
+					s = "%e%"
+				}
+			case 'f':
+				if v, ok := getFloat(field); ok {
+					s = p.fmt.F(v).str()
+				} else {
+					s = "%f%";
+				}
+			case 'g':
+				if v, ok := getFloat(field); ok {
+					s = p.fmt.G(v).str()
+				} else {
+					s = "%g%"
+				}
+
+			// string
+			case 's':
+				if v, ok := getString(field); ok {
+					s = p.fmt.s(v).str()
+				} else {
+					s = "%s%"
+				}
+
+			// pointer
+			case 'p':
+				if v, ok := getPtr(field); ok {
+					s = "0x" + p.fmt.uX(int64(v)).str()
+				} else {
+					s = "%p%"
+				}
+
+			default:
+				s = "?" + string(c) + "?";
+		}
+		p.addstr(s);
+	}
+}
+
+func (p *P) doprint(v reflect.StructValue, is_println bool) {
+	prev_string := false;
+	for fieldnum := 0; fieldnum < v.Len();  fieldnum++ {
+		// always add spaces if we're doing println
+		field := v.Field(fieldnum);
+		s := "";
+		if is_println {
+			if fieldnum > 0 {
+				p.add(' ')
+			}
+		} else if field.Kind() != reflect.StringKind && !prev_string{
+			// if not doing println, add spaces if neither side is a string
+			p.add(' ')
+		}
+		switch field.Kind() {
+		case reflect.Int8Kind, reflect.Int16Kind, reflect.Int32Kind, reflect.Int64Kind:
+			v, signed, ok := getInt(field);
+			s = p.fmt.D(v).str();
+		case reflect.Uint8Kind, reflect.Uint16Kind, reflect.Uint32Kind, reflect.Uint64Kind:
+			v, signed, ok := getInt(field);
+			s = p.fmt.uD(v).str();
+		case reflect.Float32Kind, reflect.Float64Kind, reflect.Float80Kind:
+			v, ok := getFloat(field);
+			s = p.fmt.G(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.uX(int64(v)).str();
+		default:
+			s = "???";
+		}
+		p.addstr(s);
+		prev_string = field.Kind() == reflect.StringKind;
+	}
+	if is_println {
+		p.add('\n')
+	}
+}
diff --git a/src/lib/reflect/tostring.go b/src/lib/reflect/tostring.go
index ca3ada9fdd..4b3ff78ca4 100644
--- a/src/lib/reflect/tostring.go
+++ b/src/lib/reflect/tostring.go
@@ -151,7 +151,7 @@ func ValueToString(val Value) string {
 		return val.(StringValue).Get();
 	case PtrKind:
 		v := val.(PtrValue);
-		return TypeToString(typ, false) + "(" + integer(int64(v.Indirect())) + ")";
+		return TypeToString(typ, false) + "(" + integer(int64(v.Get())) + ")";
 	case ArrayKind:
 		t := typ.(ArrayType);
 		v := val.(ArrayValue);
diff --git a/src/lib/reflect/value.go b/src/lib/reflect/value.go
index 7d6172dada..80ad46e6d8 100644
--- a/src/lib/reflect/value.go
+++ b/src/lib/reflect/value.go
@@ -444,9 +444,9 @@ func (v *StringValueStruct) Put(s string) {
 
 export type PtrValue interface {
 	Kind()	int;
-	Sub()	Value;
 	Type()	Type;
-	Indirect()	Addr;
+	Sub()	Value;
+	Get()	Addr;
 }
 
 type PtrValueStruct struct {
@@ -462,12 +462,12 @@ func (v *PtrValueStruct) Type() Type {
 	return v.typ
 }
 
-func (v *PtrValueStruct) Indirect() Addr {
+func (v *PtrValueStruct) Get() Addr {
 	return *AddrToPtrAddr(v.addr)
 }
 
 func (v *PtrValueStruct) Sub() Value {
-	return NewValueAddr(v.typ.(PtrType).Sub(), v.Indirect());
+	return NewValueAddr(v.typ.(PtrType).Sub(), v.Get());
 }
 
 func PtrCreator(typ Type, addr Addr) Value {