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-rw-r--r--src/fmt/print.go1172
1 files changed, 1172 insertions, 0 deletions
diff --git a/src/fmt/print.go b/src/fmt/print.go
new file mode 100644
index 0000000..1c37c3c
--- /dev/null
+++ b/src/fmt/print.go
@@ -0,0 +1,1172 @@
+// 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 (
+ "internal/fmtsort"
+ "io"
+ "os"
+ "reflect"
+ "sync"
+ "unicode/utf8"
+)
+
+// 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>"
+)
+
+// State represents the printer state passed to custom formatters.
+// It provides access to the io.Writer interface plus information about
+// the flags and options for the operand's format specifier.
+type State interface {
+ // Write is the function to call to emit formatted output to be printed.
+ Write(b []byte) (n int, err error)
+ // Width returns the value of the width option and whether it has been set.
+ Width() (wid int, ok bool)
+ // Precision returns the value of the precision option and whether it has been set.
+ Precision() (prec int, ok bool)
+
+ // Flag reports whether the flag c, a character, has been set.
+ Flag(c int) bool
+}
+
+// Formatter is implemented by any value that has a Format method.
+// The implementation controls how State and rune are interpreted,
+// and may call Sprint(f) or Fprint(f) etc. to generate its output.
+type Formatter interface {
+ Format(f State, verb rune)
+}
+
+// Stringer is implemented by any value that has a String method,
+// which defines the ``native'' format for that value.
+// The String method is used to print values passed as an operand
+// to any format that accepts a string or to an unformatted printer
+// such as Print.
+type Stringer interface {
+ String() string
+}
+
+// GoStringer is implemented by any value that has a GoString method,
+// which defines the Go syntax for that value.
+// The GoString method is used to print values passed as an operand
+// to a %#v format.
+type GoStringer interface {
+ GoString() string
+}
+
+// Use simple []byte instead of bytes.Buffer to avoid large dependency.
+type buffer []byte
+
+func (b *buffer) write(p []byte) {
+ *b = append(*b, p...)
+}
+
+func (b *buffer) writeString(s string) {
+ *b = append(*b, s...)
+}
+
+func (b *buffer) writeByte(c byte) {
+ *b = append(*b, c)
+}
+
+func (bp *buffer) writeRune(r rune) {
+ if r < utf8.RuneSelf {
+ *bp = append(*bp, byte(r))
+ return
+ }
+
+ b := *bp
+ n := len(b)
+ for n+utf8.UTFMax > cap(b) {
+ b = append(b, 0)
+ }
+ w := utf8.EncodeRune(b[n:n+utf8.UTFMax], r)
+ *bp = b[:n+w]
+}
+
+// pp is used to store a printer's state and is reused with sync.Pool to avoid allocations.
+type pp struct {
+ buf buffer
+
+ // arg holds the current item, as an interface{}.
+ arg any
+
+ // 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 fmt
+
+ // 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
+ // wrapErrs is set when the format string may contain a %w verb.
+ wrapErrs bool
+ // wrappedErr records the target of the %w verb.
+ wrappedErr error
+}
+
+var ppFree = sync.Pool{
+ New: func() any { return new(pp) },
+}
+
+// newPrinter allocates a new pp struct or grabs a cached one.
+func newPrinter() *pp {
+ p := ppFree.Get().(*pp)
+ p.panicking = false
+ p.erroring = false
+ p.wrapErrs = false
+ p.fmt.init(&p.buf)
+ return p
+}
+
+// free saves used pp structs in ppFree; avoids an allocation per invocation.
+func (p *pp) free() {
+ // Proper usage of a sync.Pool requires each entry to have approximately
+ // the same memory cost. To obtain this property when the stored type
+ // contains a variably-sized buffer, we add a hard limit on the maximum buffer
+ // to place back in the pool.
+ //
+ // See https://golang.org/issue/23199
+ if cap(p.buf) > 64<<10 {
+ return
+ }
+
+ p.buf = p.buf[:0]
+ p.arg = nil
+ p.value = reflect.Value{}
+ p.wrappedErr = nil
+ ppFree.Put(p)
+}
+
+func (p *pp) Width() (wid int, ok bool) { return p.fmt.wid, p.fmt.widPresent }
+
+func (p *pp) Precision() (prec int, ok bool) { return p.fmt.prec, p.fmt.precPresent }
+
+func (p *pp) 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
+}
+
+// Implement Write so we can call Fprintf on a pp (through State), for
+// recursive use in custom verbs.
+func (p *pp) Write(b []byte) (ret int, err error) {
+ p.buf.write(b)
+ return len(b), nil
+}
+
+// Implement WriteString so that we can call io.WriteString
+// on a pp (through state), for efficiency.
+func (p *pp) WriteString(s string) (ret int, err error) {
+ p.buf.writeString(s)
+ return len(s), nil
+}
+
+// These routines end in 'f' and take a format string.
+
+// Fprintf formats according to a format specifier and writes to w.
+// It returns the number of bytes written and any write error encountered.
+func Fprintf(w io.Writer, format string, a ...any) (n int, err error) {
+ p := newPrinter()
+ p.doPrintf(format, a)
+ n, err = w.Write(p.buf)
+ p.free()
+ return
+}
+
+// Printf formats according to a format specifier and writes to standard output.
+// It returns the number of bytes written and any write error encountered.
+func Printf(format string, a ...any) (n int, err error) {
+ return Fprintf(os.Stdout, format, a...)
+}
+
+// Sprintf formats according to a format specifier and returns the resulting string.
+func Sprintf(format string, a ...any) string {
+ p := newPrinter()
+ p.doPrintf(format, a)
+ s := string(p.buf)
+ p.free()
+ return s
+}
+
+// These routines do not take a format string
+
+// Fprint formats using the default formats for its operands and writes to w.
+// Spaces are added between operands when neither is a string.
+// It returns the number of bytes written and any write error encountered.
+func Fprint(w io.Writer, a ...any) (n int, err error) {
+ p := newPrinter()
+ p.doPrint(a)
+ n, err = w.Write(p.buf)
+ p.free()
+ return
+}
+
+// Print formats using the default formats for its operands and writes to standard output.
+// Spaces are added between operands when neither is a string.
+// It returns the number of bytes written and any write error encountered.
+func Print(a ...any) (n int, err error) {
+ return Fprint(os.Stdout, a...)
+}
+
+// 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 ...any) string {
+ p := newPrinter()
+ p.doPrint(a)
+ s := string(p.buf)
+ p.free()
+ 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.
+
+// Fprintln formats using the default formats for its operands and writes to w.
+// Spaces are always added between operands and a newline is appended.
+// It returns the number of bytes written and any write error encountered.
+func Fprintln(w io.Writer, a ...any) (n int, err error) {
+ p := newPrinter()
+ p.doPrintln(a)
+ n, err = w.Write(p.buf)
+ p.free()
+ return
+}
+
+// Println formats using the default formats for its operands and writes to standard output.
+// Spaces are always added between operands and a newline is appended.
+// It returns the number of bytes written and any write error encountered.
+func Println(a ...any) (n int, err error) {
+ return Fprintln(os.Stdout, a...)
+}
+
+// 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 ...any) string {
+ p := newPrinter()
+ p.doPrintln(a)
+ s := string(p.buf)
+ p.free()
+ return s
+}
+
+// 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 *pp) unknownType(v reflect.Value) {
+ if !v.IsValid() {
+ p.buf.writeString(nilAngleString)
+ return
+ }
+ p.buf.writeByte('?')
+ p.buf.writeString(v.Type().String())
+ p.buf.writeByte('?')
+}
+
+func (p *pp) badVerb(verb rune) {
+ p.erroring = true
+ p.buf.writeString(percentBangString)
+ p.buf.writeRune(verb)
+ p.buf.writeByte('(')
+ switch {
+ case p.arg != nil:
+ p.buf.writeString(reflect.TypeOf(p.arg).String())
+ p.buf.writeByte('=')
+ p.printArg(p.arg, 'v')
+ case p.value.IsValid():
+ p.buf.writeString(p.value.Type().String())
+ p.buf.writeByte('=')
+ p.printValue(p.value, 'v', 0)
+ default:
+ p.buf.writeString(nilAngleString)
+ }
+ p.buf.writeByte(')')
+ p.erroring = false
+}
+
+func (p *pp) fmtBool(v bool, verb rune) {
+ switch verb {
+ case 't', 'v':
+ p.fmt.fmtBoolean(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 *pp) fmt0x64(v uint64, leading0x bool) {
+ sharp := p.fmt.sharp
+ p.fmt.sharp = leading0x
+ p.fmt.fmtInteger(v, 16, unsigned, 'v', ldigits)
+ p.fmt.sharp = sharp
+}
+
+// fmtInteger formats a signed or unsigned integer.
+func (p *pp) fmtInteger(v uint64, isSigned bool, verb rune) {
+ switch verb {
+ case 'v':
+ if p.fmt.sharpV && !isSigned {
+ p.fmt0x64(v, true)
+ } else {
+ p.fmt.fmtInteger(v, 10, isSigned, verb, ldigits)
+ }
+ case 'd':
+ p.fmt.fmtInteger(v, 10, isSigned, verb, ldigits)
+ case 'b':
+ p.fmt.fmtInteger(v, 2, isSigned, verb, ldigits)
+ case 'o', 'O':
+ p.fmt.fmtInteger(v, 8, isSigned, verb, ldigits)
+ case 'x':
+ p.fmt.fmtInteger(v, 16, isSigned, verb, ldigits)
+ case 'X':
+ p.fmt.fmtInteger(v, 16, isSigned, verb, udigits)
+ case 'c':
+ p.fmt.fmtC(v)
+ case 'q':
+ p.fmt.fmtQc(v)
+ case 'U':
+ p.fmt.fmtUnicode(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 *pp) fmtFloat(v float64, size int, verb rune) {
+ switch verb {
+ case 'v':
+ p.fmt.fmtFloat(v, size, 'g', -1)
+ case 'b', 'g', 'G', 'x', 'X':
+ p.fmt.fmtFloat(v, size, verb, -1)
+ case 'f', 'e', 'E':
+ p.fmt.fmtFloat(v, size, verb, 6)
+ case 'F':
+ p.fmt.fmtFloat(v, size, 'f', 6)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+// 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 *pp) 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', 'x', 'X', 'f', 'F', 'e', 'E':
+ oldPlus := p.fmt.plus
+ p.buf.writeByte('(')
+ p.fmtFloat(real(v), size/2, verb)
+ // Imaginary part always has a sign.
+ p.fmt.plus = true
+ p.fmtFloat(imag(v), size/2, verb)
+ p.buf.writeString("i)")
+ p.fmt.plus = oldPlus
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) fmtString(v string, verb rune) {
+ switch verb {
+ case 'v':
+ if p.fmt.sharpV {
+ p.fmt.fmtQ(v)
+ } else {
+ p.fmt.fmtS(v)
+ }
+ case 's':
+ p.fmt.fmtS(v)
+ case 'x':
+ p.fmt.fmtSx(v, ldigits)
+ case 'X':
+ p.fmt.fmtSx(v, udigits)
+ case 'q':
+ p.fmt.fmtQ(v)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) fmtBytes(v []byte, verb rune, typeString string) {
+ switch verb {
+ case 'v', 'd':
+ if p.fmt.sharpV {
+ p.buf.writeString(typeString)
+ if v == nil {
+ p.buf.writeString(nilParenString)
+ return
+ }
+ p.buf.writeByte('{')
+ for i, c := range v {
+ if i > 0 {
+ p.buf.writeString(commaSpaceString)
+ }
+ p.fmt0x64(uint64(c), true)
+ }
+ p.buf.writeByte('}')
+ } else {
+ p.buf.writeByte('[')
+ for i, c := range v {
+ if i > 0 {
+ p.buf.writeByte(' ')
+ }
+ p.fmt.fmtInteger(uint64(c), 10, unsigned, verb, ldigits)
+ }
+ p.buf.writeByte(']')
+ }
+ case 's':
+ p.fmt.fmtBs(v)
+ case 'x':
+ p.fmt.fmtBx(v, ldigits)
+ case 'X':
+ p.fmt.fmtBx(v, udigits)
+ case 'q':
+ p.fmt.fmtQ(string(v))
+ default:
+ p.printValue(reflect.ValueOf(v), verb, 0)
+ }
+}
+
+func (p *pp) fmtPointer(value reflect.Value, verb rune) {
+ var u uintptr
+ switch value.Kind() {
+ case reflect.Chan, reflect.Func, reflect.Map, reflect.Pointer, reflect.Slice, reflect.UnsafePointer:
+ u = value.Pointer()
+ default:
+ p.badVerb(verb)
+ return
+ }
+
+ switch verb {
+ case 'v':
+ if p.fmt.sharpV {
+ p.buf.writeByte('(')
+ p.buf.writeString(value.Type().String())
+ p.buf.writeString(")(")
+ if u == 0 {
+ p.buf.writeString(nilString)
+ } else {
+ p.fmt0x64(uint64(u), true)
+ }
+ p.buf.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':
+ p.fmtInteger(uint64(u), unsigned, verb)
+ default:
+ p.badVerb(verb)
+ }
+}
+
+func (p *pp) catchPanic(arg any, verb rune, method string) {
+ 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.Pointer && v.IsNil() {
+ p.buf.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.buf.writeString(percentBangString)
+ p.buf.writeRune(verb)
+ p.buf.writeString(panicString)
+ p.buf.writeString(method)
+ p.buf.writeString(" method: ")
+ p.panicking = true
+ p.printArg(err, 'v')
+ p.panicking = false
+ p.buf.writeByte(')')
+
+ p.fmt.fmtFlags = oldFlags
+ }
+}
+
+func (p *pp) handleMethods(verb rune) (handled bool) {
+ if p.erroring {
+ return
+ }
+ if verb == 'w' {
+ // It is invalid to use %w other than with Errorf, more than once,
+ // or with a non-error arg.
+ err, ok := p.arg.(error)
+ if !ok || !p.wrapErrs || p.wrappedErr != nil {
+ p.wrappedErr = nil
+ p.wrapErrs = false
+ p.badVerb(verb)
+ return true
+ }
+ p.wrappedErr = err
+ // If the arg is a Formatter, pass 'v' as the verb to it.
+ verb = 'v'
+ }
+
+ // Is it a Formatter?
+ if formatter, ok := p.arg.(Formatter); ok {
+ handled = true
+ defer p.catchPanic(p.arg, verb, "Format")
+ 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.(GoStringer); ok {
+ handled = true
+ defer p.catchPanic(p.arg, verb, "GoString")
+ // Print the result of GoString unadorned.
+ p.fmt.fmtS(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, "Error")
+ p.fmtString(v.Error(), verb)
+ return
+
+ case Stringer:
+ handled = true
+ defer p.catchPanic(p.arg, verb, "String")
+ p.fmtString(v.String(), verb)
+ return
+ }
+ }
+ }
+ return false
+}
+
+func (p *pp) printArg(arg any, 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.fmtS(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 *pp) 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.buf.writeString(invReflectString)
+ } else {
+ switch verb {
+ case 'v':
+ p.buf.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.buf.writeString(f.Type().String())
+ if f.IsNil() {
+ p.buf.writeString(nilParenString)
+ return
+ }
+ p.buf.writeByte('{')
+ } else {
+ p.buf.writeString(mapString)
+ }
+ sorted := fmtsort.Sort(f)
+ for i, key := range sorted.Key {
+ if i > 0 {
+ if p.fmt.sharpV {
+ p.buf.writeString(commaSpaceString)
+ } else {
+ p.buf.writeByte(' ')
+ }
+ }
+ p.printValue(key, verb, depth+1)
+ p.buf.writeByte(':')
+ p.printValue(sorted.Value[i], verb, depth+1)
+ }
+ if p.fmt.sharpV {
+ p.buf.writeByte('}')
+ } else {
+ p.buf.writeByte(']')
+ }
+ case reflect.Struct:
+ if p.fmt.sharpV {
+ p.buf.writeString(f.Type().String())
+ }
+ p.buf.writeByte('{')
+ for i := 0; i < f.NumField(); i++ {
+ if i > 0 {
+ if p.fmt.sharpV {
+ p.buf.writeString(commaSpaceString)
+ } else {
+ p.buf.writeByte(' ')
+ }
+ }
+ if p.fmt.plusV || p.fmt.sharpV {
+ if name := f.Type().Field(i).Name; name != "" {
+ p.buf.writeString(name)
+ p.buf.writeByte(':')
+ }
+ }
+ p.printValue(getField(f, i), verb, depth+1)
+ }
+ p.buf.writeByte('}')
+ case reflect.Interface:
+ value := f.Elem()
+ if !value.IsValid() {
+ if p.fmt.sharpV {
+ p.buf.writeString(f.Type().String())
+ p.buf.writeString(nilParenString)
+ } else {
+ p.buf.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.buf.writeString(f.Type().String())
+ if f.Kind() == reflect.Slice && f.IsNil() {
+ p.buf.writeString(nilParenString)
+ return
+ }
+ p.buf.writeByte('{')
+ for i := 0; i < f.Len(); i++ {
+ if i > 0 {
+ p.buf.writeString(commaSpaceString)
+ }
+ p.printValue(f.Index(i), verb, depth+1)
+ }
+ p.buf.writeByte('}')
+ } else {
+ p.buf.writeByte('[')
+ for i := 0; i < f.Len(); i++ {
+ if i > 0 {
+ p.buf.writeByte(' ')
+ }
+ p.printValue(f.Index(i), verb, depth+1)
+ }
+ p.buf.writeByte(']')
+ }
+ case reflect.Pointer:
+ // 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.buf.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 intFromArg(a []any, argNum int) (num int, isInt bool, newArgNum int) {
+ newArgNum = argNum
+ if argNum < len(a) {
+ num, isInt = a[argNum].(int) // Almost always OK.
+ if !isInt {
+ // Work harder.
+ switch v := reflect.ValueOf(a[argNum]); 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.
+ }
+ }
+ newArgNum = argNum + 1
+ 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
+}
+
+// argNumber 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 *pp) argNumber(argNum int, format string, i int, numArgs int) (newArgNum, newi int, found bool) {
+ if len(format) <= i || format[i] != '[' {
+ return argNum, i, false
+ }
+ p.reordered = true
+ index, wid, ok := parseArgNumber(format[i:])
+ if ok && 0 <= index && index < numArgs {
+ return index, i + wid, true
+ }
+ p.goodArgNum = false
+ return argNum, i + wid, ok
+}
+
+func (p *pp) badArgNum(verb rune) {
+ p.buf.writeString(percentBangString)
+ p.buf.writeRune(verb)
+ p.buf.writeString(badIndexString)
+}
+
+func (p *pp) missingArg(verb rune) {
+ p.buf.writeString(percentBangString)
+ p.buf.writeRune(verb)
+ p.buf.writeString(missingString)
+}
+
+func (p *pp) doPrintf(format string, a []any) {
+ end := len(format)
+ argNum := 0 // we process one argument per non-trivial format
+ afterIndex := false // previous item in format was an index like [3].
+ p.reordered = false
+formatLoop:
+ for i := 0; i < end; {
+ p.goodArgNum = true
+ lasti := i
+ for i < end && format[i] != '%' {
+ i++
+ }
+ if i > lasti {
+ p.buf.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' && argNum < len(a) {
+ 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(a[argNum], rune(c))
+ 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?
+ argNum, i, afterIndex = p.argNumber(argNum, format, i, len(a))
+
+ // Do we have width?
+ if i < end && format[i] == '*' {
+ i++
+ p.fmt.wid, p.fmt.widPresent, argNum = intFromArg(a, argNum)
+
+ if !p.fmt.widPresent {
+ p.buf.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
+ }
+ argNum, i, afterIndex = p.argNumber(argNum, format, i, len(a))
+ if i < end && format[i] == '*' {
+ i++
+ p.fmt.prec, p.fmt.precPresent, argNum = intFromArg(a, argNum)
+ // 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.buf.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 {
+ argNum, i, afterIndex = p.argNumber(argNum, format, i, len(a))
+ }
+
+ if i >= end {
+ p.buf.writeString(noVerbString)
+ break
+ }
+
+ verb, size := rune(format[i]), 1
+ if verb >= utf8.RuneSelf {
+ verb, size = utf8.DecodeRuneInString(format[i:])
+ }
+ i += size
+
+ switch {
+ case verb == '%': // Percent does not absorb operands and ignores f.wid and f.prec.
+ p.buf.writeByte('%')
+ case !p.goodArgNum:
+ p.badArgNum(verb)
+ case argNum >= len(a): // 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(a[argNum], verb)
+ argNum++
+ }
+ }
+
+ // Check for extra arguments unless the call accessed the arguments
+ // out of order, in which case it's too expensive to detect if they've all
+ // been used and arguably OK if they're not.
+ if !p.reordered && argNum < len(a) {
+ p.fmt.clearflags()
+ p.buf.writeString(extraString)
+ for i, arg := range a[argNum:] {
+ if i > 0 {
+ p.buf.writeString(commaSpaceString)
+ }
+ if arg == nil {
+ p.buf.writeString(nilAngleString)
+ } else {
+ p.buf.writeString(reflect.TypeOf(arg).String())
+ p.buf.writeByte('=')
+ p.printArg(arg, 'v')
+ }
+ }
+ p.buf.writeByte(')')
+ }
+}
+
+func (p *pp) doPrint(a []any) {
+ 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.buf.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 *pp) doPrintln(a []any) {
+ for argNum, arg := range a {
+ if argNum > 0 {
+ p.buf.writeByte(' ')
+ }
+ p.printArg(arg, 'v')
+ }
+ p.buf.writeByte('\n')
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-01 01:49:31 +0000