--- /dev/null
+// Copyright 2017 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 message
+
+import (
+ "bytes"
+ "fmt" // TODO: consider copying interfaces from package fmt to avoid dependency.
+ "math"
+ "reflect"
+ "unicode/utf8"
+
+ "golang.org/x/text/internal/number"
+ "golang.org/x/text/language"
+ "golang.org/x/text/message/catalog"
+)
+
+// Strings for use with buffer.WriteString.
+// This is less overhead than using buffer.Write with byte arrays.
+const (
+ commaSpaceString = ", "
+ nilAngleString = "<nil>"
+ nilParenString = "(nil)"
+ nilString = "nil"
+ mapString = "map["
+ percentBangString = "%!"
+ missingString = "(MISSING)"
+ badIndexString = "(BADINDEX)"
+ panicString = "(PANIC="
+ extraString = "%!(EXTRA "
+ badWidthString = "%!(BADWIDTH)"
+ badPrecString = "%!(BADPREC)"
+ noVerbString = "%!(NOVERB)"
+
+ invReflectString = "<invalid reflect.Value>"
+)
+
+// printer is used to store a printer's state.
+// It implements "golang.org/x/text/internal/format".State.
+type printer struct {
+ // the context for looking up message translations
+ catContext *catalog.Context
+ // the language
+ tag language.Tag
+
+ // buffer for accumulating output.
+ bytes.Buffer
+
+ // retain arguments across calls.
+ args []interface{}
+ // retain current argument number across calls
+ argNum int
+ // arg holds the current item, as an interface{}.
+ arg interface{}
+ // value is used instead of arg for reflect values.
+ value reflect.Value
+
+ // fmt is used to format basic items such as integers or strings.
+ fmt formatInfo
+
+ // reordered records whether the format string used argument reordering.
+ reordered bool
+ // goodArgNum records whether the most recent reordering directive was valid.
+ goodArgNum bool
+ // panicking is set by catchPanic to avoid infinite panic, recover, panic, ... recursion.
+ panicking bool
+ // erroring is set when printing an error string to guard against calling handleMethods.
+ erroring bool
+
+ toDecimal number.Formatter
+ toScientific number.Formatter
+}
+
+func (p *printer) reset() {
+ p.Buffer.Reset()
+ p.argNum = 0
+ p.reordered = false
+ p.panicking = false
+ p.erroring = false
+ p.fmt.init(&p.Buffer)
+}
+
+// Language implements "golang.org/x/text/internal/format".State.
+func (p *printer) Language() language.Tag { return p.tag }
+
+func (p *printer) Width() (wid int, ok bool) { return p.fmt.wid, p.fmt.widPresent }
+
+func (p *printer) Precision() (prec int, ok bool) { return p.fmt.prec, p.fmt.precPresent }
+
+func (p *printer) Flag(b int) bool {
+ switch b {
+ case '-':
+ return p.fmt.minus
+ case '+':
+ return p.fmt.plus || p.fmt.plusV
+ case '#':
+ return p.fmt.sharp || p.fmt.sharpV
+ case ' ':
+ return p.fmt.space
+ case '0':
+ return p.fmt.zero
+ }
+ return false
+}
+
+// getField gets the i'th field of the struct value.
+// If the field is itself is an interface, return a value for
+// the thing inside the interface, not the interface itself.
+func getField(v reflect.Value, i int) reflect.Value {
+ val := v.Field(i)
+ if val.Kind() == reflect.Interface && !val.IsNil() {
+ val = val.Elem()
+ }
+ return val
+}
+
+// tooLarge reports whether the magnitude of the integer is
+// too large to be used as a formatting width or precision.
+func tooLarge(x int) bool {
+ const max int = 1e6
+ return x > max || x < -max
+}
+
+// parsenum converts ASCII to integer. num is 0 (and isnum is false) if no number present.
+func parsenum(s string, start, end int) (num int, isnum bool, newi int) {
+ if start >= end {
+ return 0, false, end
+ }
+ for newi = start; newi < end && '0' <= s[newi] && s[newi] <= '9'; newi++ {
+ if tooLarge(num) {
+ return 0, false, end // Overflow; crazy long number most likely.
+ }
+ num = num*10 + int(s[newi]-'0')
+ isnum = true
+ }
+ return
+}
+
+func (p *printer) unknownType(v reflect.Value) {
+ if !v.IsValid() {
+ p.WriteString(nilAngleString)
+ return
+ }
+ p.WriteByte('?')
+ p.WriteString(v.Type().String())
+ p.WriteByte('?')
+}
+
+func (p *printer) badVerb(verb rune) {
+ p.erroring = true
+ p.WriteString(percentBangString)
+ p.WriteRune(verb)
+ p.WriteByte('(')
+ switch {
+ case p.arg != nil:
+ p.WriteString(reflect.TypeOf(p.arg).String())
+ p.WriteByte('=')
+ p.printArg(p.arg, 'v')
+ case p.value.IsValid():
+ p.WriteString(p.value.Type().String())
+ p.WriteByte('=')
+ p.printValue(p.value, 'v', 0)
+ default:
+ p.WriteString(nilAngleString)
+ }
+ p.WriteByte(')')
+ p.erroring = false
+}
+
+func (p *printer) fmtBool(v bool, verb rune) {
+ switch verb {
+ case 't', 'v':
+ p.fmt.fmt_boolean(v)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+// fmt0x64 formats a uint64 in hexadecimal and prefixes it with 0x or
+// not, as requested, by temporarily setting the sharp flag.
+func (p *printer) fmt0x64(v uint64, leading0x bool) {
+ sharp := p.fmt.sharp
+ p.fmt.sharp = leading0x
+ p.fmt.fmt_integer(v, 16, unsigned, ldigits)
+ p.fmt.sharp = sharp
+}
+
+// fmtInteger formats a signed or unsigned integer.
+func (p *printer) fmtInteger(v uint64, isSigned bool, verb rune) {
+ switch verb {
+ case 'v':
+ if p.fmt.sharpV && !isSigned {
+ p.fmt0x64(v, true)
+ return
+ }
+ fallthrough
+ case 'd':
+ if p.fmt.sharp || p.fmt.sharpV {
+ p.fmt.fmt_integer(v, 10, isSigned, ldigits)
+ } else {
+ p.fmtDecimalInt(v, isSigned)
+ }
+ case 'b':
+ p.fmt.fmt_integer(v, 2, isSigned, ldigits)
+ case 'o':
+ p.fmt.fmt_integer(v, 8, isSigned, ldigits)
+ case 'x':
+ p.fmt.fmt_integer(v, 16, isSigned, ldigits)
+ case 'X':
+ p.fmt.fmt_integer(v, 16, isSigned, udigits)
+ case 'c':
+ p.fmt.fmt_c(v)
+ case 'q':
+ if v <= utf8.MaxRune {
+ p.fmt.fmt_qc(v)
+ } else {
+ p.badVerb(verb)
+ }
+ case 'U':
+ p.fmt.fmt_unicode(v)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+// fmtFloat formats a float. The default precision for each verb
+// is specified as last argument in the call to fmt_float.
+func (p *printer) fmtFloat(v float64, size int, verb rune) {
+ switch verb {
+ case 'b':
+ p.fmt.fmt_float(v, size, verb, -1)
+ case 'v':
+ verb = 'g'
+ fallthrough
+ case 'g', 'G':
+ if p.fmt.sharp || p.fmt.sharpV {
+ p.fmt.fmt_float(v, size, verb, -1)
+ } else {
+ p.fmtVariableFloat(v, size)
+ }
+ case 'e', 'E':
+ if p.fmt.sharp || p.fmt.sharpV {
+ p.fmt.fmt_float(v, size, verb, 6)
+ } else {
+ p.fmtScientific(v, size, 6)
+ }
+ case 'f', 'F':
+ if p.fmt.sharp || p.fmt.sharpV {
+ p.fmt.fmt_float(v, size, verb, 6)
+ } else {
+ p.fmtDecimalFloat(v, size, 6)
+ }
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *printer) setFlags(f *number.Formatter) {
+ f.Flags &^= number.ElideSign
+ if p.fmt.plus || p.fmt.space {
+ f.Flags |= number.AlwaysSign
+ if !p.fmt.plus {
+ f.Flags |= number.ElideSign
+ }
+ } else {
+ f.Flags &^= number.AlwaysSign
+ }
+}
+
+func (p *printer) updatePadding(f *number.Formatter) {
+ f.Flags &^= number.PadMask
+ if p.fmt.minus {
+ f.Flags |= number.PadAfterSuffix
+ } else {
+ f.Flags |= number.PadBeforePrefix
+ }
+ f.PadRune = ' '
+ f.FormatWidth = uint16(p.fmt.wid)
+}
+
+func (p *printer) initDecimal(minFrac, maxFrac int) {
+ f := &p.toDecimal
+ f.MinIntegerDigits = 1
+ f.MaxIntegerDigits = 0
+ f.MinFractionDigits = uint8(minFrac)
+ f.MaxFractionDigits = int16(maxFrac)
+ p.setFlags(f)
+ f.PadRune = 0
+ if p.fmt.widPresent {
+ if p.fmt.zero {
+ wid := p.fmt.wid
+ // Use significant integers for this.
+ // TODO: this is not the same as width, but so be it.
+ if f.MinFractionDigits > 0 {
+ wid -= 1 + int(f.MinFractionDigits)
+ }
+ if p.fmt.plus || p.fmt.space {
+ wid--
+ }
+ if wid > 0 && wid > int(f.MinIntegerDigits) {
+ f.MinIntegerDigits = uint8(wid)
+ }
+ }
+ p.updatePadding(f)
+ }
+}
+
+func (p *printer) initScientific(minFrac, maxFrac int) {
+ f := &p.toScientific
+ if maxFrac < 0 {
+ f.SetPrecision(maxFrac)
+ } else {
+ f.SetPrecision(maxFrac + 1)
+ f.MinFractionDigits = uint8(minFrac)
+ f.MaxFractionDigits = int16(maxFrac)
+ }
+ f.MinExponentDigits = 2
+ p.setFlags(f)
+ f.PadRune = 0
+ if p.fmt.widPresent {
+ f.Flags &^= number.PadMask
+ if p.fmt.zero {
+ f.PadRune = f.Digit(0)
+ f.Flags |= number.PadAfterPrefix
+ } else {
+ f.PadRune = ' '
+ f.Flags |= number.PadBeforePrefix
+ }
+ p.updatePadding(f)
+ }
+}
+
+func (p *printer) fmtDecimalInt(v uint64, isSigned bool) {
+ var d number.Decimal
+
+ f := &p.toDecimal
+ if p.fmt.precPresent {
+ p.setFlags(f)
+ f.MinIntegerDigits = uint8(p.fmt.prec)
+ f.MaxIntegerDigits = 0
+ f.MinFractionDigits = 0
+ f.MaxFractionDigits = 0
+ if p.fmt.widPresent {
+ p.updatePadding(f)
+ }
+ } else {
+ p.initDecimal(0, 0)
+ }
+ d.ConvertInt(p.toDecimal.RoundingContext, isSigned, v)
+
+ out := p.toDecimal.Format([]byte(nil), &d)
+ p.Buffer.Write(out)
+}
+
+func (p *printer) fmtDecimalFloat(v float64, size, prec int) {
+ var d number.Decimal
+ if p.fmt.precPresent {
+ prec = p.fmt.prec
+ }
+ p.initDecimal(prec, prec)
+ d.ConvertFloat(p.toDecimal.RoundingContext, v, size)
+
+ out := p.toDecimal.Format([]byte(nil), &d)
+ p.Buffer.Write(out)
+}
+
+func (p *printer) fmtVariableFloat(v float64, size int) {
+ prec := -1
+ if p.fmt.precPresent {
+ prec = p.fmt.prec
+ }
+ var d number.Decimal
+ p.initScientific(0, prec)
+ d.ConvertFloat(p.toScientific.RoundingContext, v, size)
+
+ // Copy logic of 'g' formatting from strconv. It is simplified a bit as
+ // we don't have to mind having prec > len(d.Digits).
+ shortest := prec < 0
+ ePrec := prec
+ if shortest {
+ prec = len(d.Digits)
+ ePrec = 6
+ } else if prec == 0 {
+ prec = 1
+ ePrec = 1
+ }
+ exp := int(d.Exp) - 1
+ if exp < -4 || exp >= ePrec {
+ p.initScientific(0, prec)
+
+ out := p.toScientific.Format([]byte(nil), &d)
+ p.Buffer.Write(out)
+ } else {
+ if prec > int(d.Exp) {
+ prec = len(d.Digits)
+ }
+ if prec -= int(d.Exp); prec < 0 {
+ prec = 0
+ }
+ p.initDecimal(0, prec)
+
+ out := p.toDecimal.Format([]byte(nil), &d)
+ p.Buffer.Write(out)
+ }
+}
+
+func (p *printer) fmtScientific(v float64, size, prec int) {
+ var d number.Decimal
+ if p.fmt.precPresent {
+ prec = p.fmt.prec
+ }
+ p.initScientific(prec, prec)
+ rc := p.toScientific.RoundingContext
+ d.ConvertFloat(rc, v, size)
+
+ out := p.toScientific.Format([]byte(nil), &d)
+ p.Buffer.Write(out)
+
+}
+
+// fmtComplex formats a complex number v with
+// r = real(v) and j = imag(v) as (r+ji) using
+// fmtFloat for r and j formatting.
+func (p *printer) fmtComplex(v complex128, size int, verb rune) {
+ // Make sure any unsupported verbs are found before the
+ // calls to fmtFloat to not generate an incorrect error string.
+ switch verb {
+ case 'v', 'b', 'g', 'G', 'f', 'F', 'e', 'E':
+ p.WriteByte('(')
+ p.fmtFloat(real(v), size/2, verb)
+ // Imaginary part always has a sign.
+ if math.IsNaN(imag(v)) {
+ // By CLDR's rules, NaNs do not use patterns or signs. As this code
+ // relies on AlwaysSign working for imaginary parts, we need to
+ // manually handle NaNs.
+ f := &p.toScientific
+ p.setFlags(f)
+ p.updatePadding(f)
+ p.setFlags(f)
+ nan := f.Symbol(number.SymNan)
+ extra := 0
+ if w, ok := p.Width(); ok {
+ extra = w - utf8.RuneCountInString(nan) - 1
+ }
+ if f.Flags&number.PadAfterNumber == 0 {
+ for ; extra > 0; extra-- {
+ p.WriteRune(f.PadRune)
+ }
+ }
+ p.WriteString(f.Symbol(number.SymPlusSign))
+ p.WriteString(nan)
+ for ; extra > 0; extra-- {
+ p.WriteRune(f.PadRune)
+ }
+ p.WriteString("i)")
+ return
+ }
+ oldPlus := p.fmt.plus
+ p.fmt.plus = true
+ p.fmtFloat(imag(v), size/2, verb)
+ p.WriteString("i)") // TODO: use symbol?
+ p.fmt.plus = oldPlus
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *printer) fmtString(v string, verb rune) {
+ switch verb {
+ case 'v':
+ if p.fmt.sharpV {
+ p.fmt.fmt_q(v)
+ } else {
+ p.fmt.fmt_s(v)
+ }
+ case 's':
+ p.fmt.fmt_s(v)
+ case 'x':
+ p.fmt.fmt_sx(v, ldigits)
+ case 'X':
+ p.fmt.fmt_sx(v, udigits)
+ case 'q':
+ p.fmt.fmt_q(v)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *printer) fmtBytes(v []byte, verb rune, typeString string) {
+ switch verb {
+ case 'v', 'd':
+ if p.fmt.sharpV {
+ p.WriteString(typeString)
+ if v == nil {
+ p.WriteString(nilParenString)
+ return
+ }
+ p.WriteByte('{')
+ for i, c := range v {
+ if i > 0 {
+ p.WriteString(commaSpaceString)
+ }
+ p.fmt0x64(uint64(c), true)
+ }
+ p.WriteByte('}')
+ } else {
+ p.WriteByte('[')
+ for i, c := range v {
+ if i > 0 {
+ p.WriteByte(' ')
+ }
+ p.fmt.fmt_integer(uint64(c), 10, unsigned, ldigits)
+ }
+ p.WriteByte(']')
+ }
+ case 's':
+ p.fmt.fmt_s(string(v))
+ case 'x':
+ p.fmt.fmt_bx(v, ldigits)
+ case 'X':
+ p.fmt.fmt_bx(v, udigits)
+ case 'q':
+ p.fmt.fmt_q(string(v))
+ default:
+ p.printValue(reflect.ValueOf(v), verb, 0)
+ }
+}
+
+func (p *printer) fmtPointer(value reflect.Value, verb rune) {
+ var u uintptr
+ switch value.Kind() {
+ case reflect.Chan, reflect.Func, reflect.Map, reflect.Ptr, reflect.Slice, reflect.UnsafePointer:
+ u = value.Pointer()
+ default:
+ p.badVerb(verb)
+ return
+ }
+
+ switch verb {
+ case 'v':
+ if p.fmt.sharpV {
+ p.WriteByte('(')
+ p.WriteString(value.Type().String())
+ p.WriteString(")(")
+ if u == 0 {
+ p.WriteString(nilString)
+ } else {
+ p.fmt0x64(uint64(u), true)
+ }
+ p.WriteByte(')')
+ } else {
+ if u == 0 {
+ p.fmt.padString(nilAngleString)
+ } else {
+ p.fmt0x64(uint64(u), !p.fmt.sharp)
+ }
+ }
+ case 'p':
+ p.fmt0x64(uint64(u), !p.fmt.sharp)
+ case 'b', 'o', 'd', 'x', 'X':
+ if verb == 'd' {
+ p.fmt.sharp = true // Print as standard go. TODO: does this make sense?
+ }
+ p.fmtInteger(uint64(u), unsigned, verb)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *printer) catchPanic(arg interface{}, verb rune) {
+ if err := recover(); err != nil {
+ // If it's a nil pointer, just say "<nil>". The likeliest causes are a
+ // Stringer that fails to guard against nil or a nil pointer for a
+ // value receiver, and in either case, "<nil>" is a nice result.
+ if v := reflect.ValueOf(arg); v.Kind() == reflect.Ptr && v.IsNil() {
+ p.WriteString(nilAngleString)
+ return
+ }
+ // Otherwise print a concise panic message. Most of the time the panic
+ // value will print itself nicely.
+ if p.panicking {
+ // Nested panics; the recursion in printArg cannot succeed.
+ panic(err)
+ }
+
+ oldFlags := p.fmt.fmtFlags
+ // For this output we want default behavior.
+ p.fmt.clearflags()
+
+ p.WriteString(percentBangString)
+ p.WriteRune(verb)
+ p.WriteString(panicString)
+ p.panicking = true
+ p.printArg(err, 'v')
+ p.panicking = false
+ p.WriteByte(')')
+
+ p.fmt.fmtFlags = oldFlags
+ }
+}
+
+func (p *printer) handleMethods(verb rune) (handled bool) {
+ if p.erroring {
+ return
+ }
+ // Is it a Formatter?
+ if formatter, ok := p.arg.(fmt.Formatter); ok {
+ handled = true
+ defer p.catchPanic(p.arg, verb)
+ formatter.Format(p, verb)
+ return
+ }
+
+ // If we're doing Go syntax and the argument knows how to supply it, take care of it now.
+ if p.fmt.sharpV {
+ if stringer, ok := p.arg.(fmt.GoStringer); ok {
+ handled = true
+ defer p.catchPanic(p.arg, verb)
+ // Print the result of GoString unadorned.
+ p.fmt.fmt_s(stringer.GoString())
+ return
+ }
+ } else {
+ // If a string is acceptable according to the format, see if
+ // the value satisfies one of the string-valued interfaces.
+ // Println etc. set verb to %v, which is "stringable".
+ switch verb {
+ case 'v', 's', 'x', 'X', 'q':
+ // Is it an error or Stringer?
+ // The duplication in the bodies is necessary:
+ // setting handled and deferring catchPanic
+ // must happen before calling the method.
+ switch v := p.arg.(type) {
+ case error:
+ handled = true
+ defer p.catchPanic(p.arg, verb)
+ p.fmtString(v.Error(), verb)
+ return
+
+ case fmt.Stringer:
+ handled = true
+ defer p.catchPanic(p.arg, verb)
+ p.fmtString(v.String(), verb)
+ return
+ }
+ }
+ }
+ return false
+}
+
+func (p *printer) printArg(arg interface{}, verb rune) {
+ p.arg = arg
+ p.value = reflect.Value{}
+
+ if arg == nil {
+ switch verb {
+ case 'T', 'v':
+ p.fmt.padString(nilAngleString)
+ default:
+ p.badVerb(verb)
+ }
+ return
+ }
+
+ // Special processing considerations.
+ // %T (the value's type) and %p (its address) are special; we always do them first.
+ switch verb {
+ case 'T':
+ p.fmt.fmt_s(reflect.TypeOf(arg).String())
+ return
+ case 'p':
+ p.fmtPointer(reflect.ValueOf(arg), 'p')
+ return
+ }
+
+ // Some types can be done without reflection.
+ switch f := arg.(type) {
+ case bool:
+ p.fmtBool(f, verb)
+ case float32:
+ p.fmtFloat(float64(f), 32, verb)
+ case float64:
+ p.fmtFloat(f, 64, verb)
+ case complex64:
+ p.fmtComplex(complex128(f), 64, verb)
+ case complex128:
+ p.fmtComplex(f, 128, verb)
+ case int:
+ p.fmtInteger(uint64(f), signed, verb)
+ case int8:
+ p.fmtInteger(uint64(f), signed, verb)
+ case int16:
+ p.fmtInteger(uint64(f), signed, verb)
+ case int32:
+ p.fmtInteger(uint64(f), signed, verb)
+ case int64:
+ p.fmtInteger(uint64(f), signed, verb)
+ case uint:
+ p.fmtInteger(uint64(f), unsigned, verb)
+ case uint8:
+ p.fmtInteger(uint64(f), unsigned, verb)
+ case uint16:
+ p.fmtInteger(uint64(f), unsigned, verb)
+ case uint32:
+ p.fmtInteger(uint64(f), unsigned, verb)
+ case uint64:
+ p.fmtInteger(f, unsigned, verb)
+ case uintptr:
+ p.fmtInteger(uint64(f), unsigned, verb)
+ case string:
+ p.fmtString(f, verb)
+ case []byte:
+ p.fmtBytes(f, verb, "[]byte")
+ case reflect.Value:
+ // Handle extractable values with special methods
+ // since printValue does not handle them at depth 0.
+ if f.IsValid() && f.CanInterface() {
+ p.arg = f.Interface()
+ if p.handleMethods(verb) {
+ return
+ }
+ }
+ p.printValue(f, verb, 0)
+ default:
+ // If the type is not simple, it might have methods.
+ if !p.handleMethods(verb) {
+ // Need to use reflection, since the type had no
+ // interface methods that could be used for formatting.
+ p.printValue(reflect.ValueOf(f), verb, 0)
+ }
+ }
+}
+
+// printValue is similar to printArg but starts with a reflect value, not an interface{} value.
+// It does not handle 'p' and 'T' verbs because these should have been already handled by printArg.
+func (p *printer) printValue(value reflect.Value, verb rune, depth int) {
+ // Handle values with special methods if not already handled by printArg (depth == 0).
+ if depth > 0 && value.IsValid() && value.CanInterface() {
+ p.arg = value.Interface()
+ if p.handleMethods(verb) {
+ return
+ }
+ }
+ p.arg = nil
+ p.value = value
+
+ switch f := value; value.Kind() {
+ case reflect.Invalid:
+ if depth == 0 {
+ p.WriteString(invReflectString)
+ } else {
+ switch verb {
+ case 'v':
+ p.WriteString(nilAngleString)
+ default:
+ p.badVerb(verb)
+ }
+ }
+ case reflect.Bool:
+ p.fmtBool(f.Bool(), verb)
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ p.fmtInteger(uint64(f.Int()), signed, verb)
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ p.fmtInteger(f.Uint(), unsigned, verb)
+ case reflect.Float32:
+ p.fmtFloat(f.Float(), 32, verb)
+ case reflect.Float64:
+ p.fmtFloat(f.Float(), 64, verb)
+ case reflect.Complex64:
+ p.fmtComplex(f.Complex(), 64, verb)
+ case reflect.Complex128:
+ p.fmtComplex(f.Complex(), 128, verb)
+ case reflect.String:
+ p.fmtString(f.String(), verb)
+ case reflect.Map:
+ if p.fmt.sharpV {
+ p.WriteString(f.Type().String())
+ if f.IsNil() {
+ p.WriteString(nilParenString)
+ return
+ }
+ p.WriteByte('{')
+ } else {
+ p.WriteString(mapString)
+ }
+ keys := f.MapKeys()
+ for i, key := range keys {
+ if i > 0 {
+ if p.fmt.sharpV {
+ p.WriteString(commaSpaceString)
+ } else {
+ p.WriteByte(' ')
+ }
+ }
+ p.printValue(key, verb, depth+1)
+ p.WriteByte(':')
+ p.printValue(f.MapIndex(key), verb, depth+1)
+ }
+ if p.fmt.sharpV {
+ p.WriteByte('}')
+ } else {
+ p.WriteByte(']')
+ }
+ case reflect.Struct:
+ if p.fmt.sharpV {
+ p.WriteString(f.Type().String())
+ }
+ p.WriteByte('{')
+ for i := 0; i < f.NumField(); i++ {
+ if i > 0 {
+ if p.fmt.sharpV {
+ p.WriteString(commaSpaceString)
+ } else {
+ p.WriteByte(' ')
+ }
+ }
+ if p.fmt.plusV || p.fmt.sharpV {
+ if name := f.Type().Field(i).Name; name != "" {
+ p.WriteString(name)
+ p.WriteByte(':')
+ }
+ }
+ p.printValue(getField(f, i), verb, depth+1)
+ }
+ p.WriteByte('}')
+ case reflect.Interface:
+ value := f.Elem()
+ if !value.IsValid() {
+ if p.fmt.sharpV {
+ p.WriteString(f.Type().String())
+ p.WriteString(nilParenString)
+ } else {
+ p.WriteString(nilAngleString)
+ }
+ } else {
+ p.printValue(value, verb, depth+1)
+ }
+ case reflect.Array, reflect.Slice:
+ switch verb {
+ case 's', 'q', 'x', 'X':
+ // Handle byte and uint8 slices and arrays special for the above verbs.
+ t := f.Type()
+ if t.Elem().Kind() == reflect.Uint8 {
+ var bytes []byte
+ if f.Kind() == reflect.Slice {
+ bytes = f.Bytes()
+ } else if f.CanAddr() {
+ bytes = f.Slice(0, f.Len()).Bytes()
+ } else {
+ // We have an array, but we cannot Slice() a non-addressable array,
+ // so we build a slice by hand. This is a rare case but it would be nice
+ // if reflection could help a little more.
+ bytes = make([]byte, f.Len())
+ for i := range bytes {
+ bytes[i] = byte(f.Index(i).Uint())
+ }
+ }
+ p.fmtBytes(bytes, verb, t.String())
+ return
+ }
+ }
+ if p.fmt.sharpV {
+ p.WriteString(f.Type().String())
+ if f.Kind() == reflect.Slice && f.IsNil() {
+ p.WriteString(nilParenString)
+ return
+ }
+ p.WriteByte('{')
+ for i := 0; i < f.Len(); i++ {
+ if i > 0 {
+ p.WriteString(commaSpaceString)
+ }
+ p.printValue(f.Index(i), verb, depth+1)
+ }
+ p.WriteByte('}')
+ } else {
+ p.WriteByte('[')
+ for i := 0; i < f.Len(); i++ {
+ if i > 0 {
+ p.WriteByte(' ')
+ }
+ p.printValue(f.Index(i), verb, depth+1)
+ }
+ p.WriteByte(']')
+ }
+ case reflect.Ptr:
+ // pointer to array or slice or struct? ok at top level
+ // but not embedded (avoid loops)
+ if depth == 0 && f.Pointer() != 0 {
+ switch a := f.Elem(); a.Kind() {
+ case reflect.Array, reflect.Slice, reflect.Struct, reflect.Map:
+ p.WriteByte('&')
+ p.printValue(a, verb, depth+1)
+ return
+ }
+ }
+ fallthrough
+ case reflect.Chan, reflect.Func, reflect.UnsafePointer:
+ p.fmtPointer(f, verb)
+ default:
+ p.unknownType(f)
+ }
+}
+
+// intFromArg gets the argNumth element of a. On return, isInt reports whether the argument has integer type.
+func (p *printer) intFromArg() (num int, isInt bool) {
+ if p.argNum < len(p.args) {
+ arg := p.args[p.argNum]
+ num, isInt = arg.(int) // Almost always OK.
+ if !isInt {
+ // Work harder.
+ switch v := reflect.ValueOf(arg); v.Kind() {
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ n := v.Int()
+ if int64(int(n)) == n {
+ num = int(n)
+ isInt = true
+ }
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ n := v.Uint()
+ if int64(n) >= 0 && uint64(int(n)) == n {
+ num = int(n)
+ isInt = true
+ }
+ default:
+ // Already 0, false.
+ }
+ }
+ p.argNum++
+ if tooLarge(num) {
+ num = 0
+ isInt = false
+ }
+ }
+ return
+}
+
+// parseArgNumber returns the value of the bracketed number, minus 1
+// (explicit argument numbers are one-indexed but we want zero-indexed).
+// The opening bracket is known to be present at format[0].
+// The returned values are the index, the number of bytes to consume
+// up to the closing paren, if present, and whether the number parsed
+// ok. The bytes to consume will be 1 if no closing paren is present.
+func parseArgNumber(format string) (index int, wid int, ok bool) {
+ // There must be at least 3 bytes: [n].
+ if len(format) < 3 {
+ return 0, 1, false
+ }
+
+ // Find closing bracket.
+ for i := 1; i < len(format); i++ {
+ if format[i] == ']' {
+ width, ok, newi := parsenum(format, 1, i)
+ if !ok || newi != i {
+ return 0, i + 1, false
+ }
+ return width - 1, i + 1, true // arg numbers are one-indexed and skip paren.
+ }
+ }
+ return 0, 1, false
+}
+
+// updateArgNumber returns the next argument to evaluate, which is either the value of the passed-in
+// argNum or the value of the bracketed integer that begins format[i:]. It also returns
+// the new value of i, that is, the index of the next byte of the format to process.
+func (p *printer) updateArgNumber(format string, i int) (newi int, found bool) {
+ if len(format) <= i || format[i] != '[' {
+ return i, false
+ }
+ p.reordered = true
+ index, wid, ok := parseArgNumber(format[i:])
+ if ok && 0 <= index && index < len(p.args) {
+ p.argNum = index
+ return i + wid, true
+ }
+ p.goodArgNum = false
+ return i + wid, ok
+}
+
+func (p *printer) badArgNum(verb rune) {
+ p.WriteString(percentBangString)
+ p.WriteRune(verb)
+ p.WriteString(badIndexString)
+}
+
+func (p *printer) missingArg(verb rune) {
+ p.WriteString(percentBangString)
+ p.WriteRune(verb)
+ p.WriteString(missingString)
+}
+
+func (p *printer) doPrintf(format string) {
+ end := len(format)
+ afterIndex := false // previous item in format was an index like [3].
+formatLoop:
+ for i := 0; i < end; {
+ p.goodArgNum = true
+ lasti := i
+ for i < end && format[i] != '%' {
+ i++
+ }
+ if i > lasti {
+ p.WriteString(format[lasti:i])
+ }
+ if i >= end {
+ // done processing format string
+ break
+ }
+
+ // Process one verb
+ i++
+
+ // Do we have flags?
+ p.fmt.clearflags()
+ simpleFormat:
+ for ; i < end; i++ {
+ c := format[i]
+ switch c {
+ case '#':
+ p.fmt.sharp = true
+ case '0':
+ p.fmt.zero = !p.fmt.minus // Only allow zero padding to the left.
+ case '+':
+ p.fmt.plus = true
+ case '-':
+ p.fmt.minus = true
+ p.fmt.zero = false // Do not pad with zeros to the right.
+ case ' ':
+ p.fmt.space = true
+ default:
+ // Fast path for common case of ascii lower case simple verbs
+ // without precision or width or argument indices.
+ if 'a' <= c && c <= 'z' && p.argNum < len(p.args) {
+ if c == 'v' {
+ // Go syntax
+ p.fmt.sharpV = p.fmt.sharp
+ p.fmt.sharp = false
+ // Struct-field syntax
+ p.fmt.plusV = p.fmt.plus
+ p.fmt.plus = false
+ }
+ p.printArg(p.Arg(p.argNum+1), rune(c))
+ p.argNum++
+ i++
+ continue formatLoop
+ }
+ // Format is more complex than simple flags and a verb or is malformed.
+ break simpleFormat
+ }
+ }
+
+ // Do we have an explicit argument index?
+ i, afterIndex = p.updateArgNumber(format, i)
+
+ // Do we have width?
+ if i < end && format[i] == '*' {
+ i++
+ p.fmt.wid, p.fmt.widPresent = p.intFromArg()
+
+ if !p.fmt.widPresent {
+ p.WriteString(badWidthString)
+ }
+
+ // We have a negative width, so take its value and ensure
+ // that the minus flag is set
+ if p.fmt.wid < 0 {
+ p.fmt.wid = -p.fmt.wid
+ p.fmt.minus = true
+ p.fmt.zero = false // Do not pad with zeros to the right.
+ }
+ afterIndex = false
+ } else {
+ p.fmt.wid, p.fmt.widPresent, i = parsenum(format, i, end)
+ if afterIndex && p.fmt.widPresent { // "%[3]2d"
+ p.goodArgNum = false
+ }
+ }
+
+ // Do we have precision?
+ if i+1 < end && format[i] == '.' {
+ i++
+ if afterIndex { // "%[3].2d"
+ p.goodArgNum = false
+ }
+ i, afterIndex = p.updateArgNumber(format, i)
+ if i < end && format[i] == '*' {
+ i++
+ p.fmt.prec, p.fmt.precPresent = p.intFromArg()
+ // Negative precision arguments don't make sense
+ if p.fmt.prec < 0 {
+ p.fmt.prec = 0
+ p.fmt.precPresent = false
+ }
+ if !p.fmt.precPresent {
+ p.WriteString(badPrecString)
+ }
+ afterIndex = false
+ } else {
+ p.fmt.prec, p.fmt.precPresent, i = parsenum(format, i, end)
+ if !p.fmt.precPresent {
+ p.fmt.prec = 0
+ p.fmt.precPresent = true
+ }
+ }
+ }
+
+ if !afterIndex {
+ i, afterIndex = p.updateArgNumber(format, i)
+ }
+
+ if i >= end {
+ p.WriteString(noVerbString)
+ break
+ }
+
+ verb, w := utf8.DecodeRuneInString(format[i:])
+ i += w
+
+ switch {
+ case verb == '%': // Percent does not absorb operands and ignores f.wid and f.prec.
+ p.WriteByte('%')
+ case !p.goodArgNum:
+ p.badArgNum(verb)
+ case p.argNum >= len(p.args): // No argument left over to print for the current verb.
+ p.missingArg(verb)
+ case verb == 'v':
+ // Go syntax
+ p.fmt.sharpV = p.fmt.sharp
+ p.fmt.sharp = false
+ // Struct-field syntax
+ p.fmt.plusV = p.fmt.plus
+ p.fmt.plus = false
+ fallthrough
+ default:
+ p.printArg(p.args[p.argNum], verb)
+ p.argNum++
+ }
+ }
+
+ // Check for extra arguments, but only if there was at least one ordered
+ // argument. Note that this behavior is necessarily different from fmt:
+ // different variants of messages may opt to drop some or all of the
+ // arguments.
+ if !p.reordered && p.argNum < len(p.args) && p.argNum != 0 {
+ p.fmt.clearflags()
+ p.WriteString(extraString)
+ for i, arg := range p.args[p.argNum:] {
+ if i > 0 {
+ p.WriteString(commaSpaceString)
+ }
+ if arg == nil {
+ p.WriteString(nilAngleString)
+ } else {
+ p.WriteString(reflect.TypeOf(arg).String())
+ p.WriteByte('=')
+ p.printArg(arg, 'v')
+ }
+ }
+ p.WriteByte(')')
+ }
+}
+
+func (p *printer) doPrint(a []interface{}) {
+ prevString := false
+ for argNum, arg := range a {
+ isString := arg != nil && reflect.TypeOf(arg).Kind() == reflect.String
+ // Add a space between two non-string arguments.
+ if argNum > 0 && !isString && !prevString {
+ p.WriteByte(' ')
+ }
+ p.printArg(arg, 'v')
+ prevString = isString
+ }
+}
+
+// doPrintln is like doPrint but always adds a space between arguments
+// and a newline after the last argument.
+func (p *printer) doPrintln(a []interface{}) {
+ for argNum, arg := range a {
+ if argNum > 0 {
+ p.WriteByte(' ')
+ }
+ p.printArg(arg, 'v')
+ }
+ p.WriteByte('\n')
+}
OSDN Git Service
