1149 lines
28 KiB
Go
1149 lines
28 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package fmt
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import (
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"errors"
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"io"
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"os"
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"reflect"
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"sync"
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"unicode/utf8"
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)
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// Some constants in the form of bytes, to avoid string overhead.
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// Needlessly fastidious, I suppose.
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var (
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commaSpaceBytes = []byte(", ")
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nilAngleBytes = []byte("<nil>")
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nilParenBytes = []byte("(nil)")
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nilBytes = []byte("nil")
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mapBytes = []byte("map[")
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missingBytes = []byte("(MISSING)")
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panicBytes = []byte("(PANIC=")
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extraBytes = []byte("%!(EXTRA ")
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irparenBytes = []byte("i)")
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bytesBytes = []byte("[]byte{")
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badWidthBytes = []byte("%!(BADWIDTH)")
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badPrecBytes = []byte("%!(BADPREC)")
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noVerbBytes = []byte("%!(NOVERB)")
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)
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// State represents the printer state passed to custom formatters.
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// It provides access to the io.Writer interface plus information about
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// the flags and options for the operand's format specifier.
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type State interface {
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// Write is the function to call to emit formatted output to be printed.
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Write(b []byte) (ret int, err error)
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// Width returns the value of the width option and whether it has been set.
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Width() (wid int, ok bool)
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// Precision returns the value of the precision option and whether it has been set.
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Precision() (prec int, ok bool)
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// Flag returns whether the flag c, a character, has been set.
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Flag(c int) bool
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}
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// Formatter is the interface implemented by values with a custom formatter.
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// The implementation of Format may call Sprint(f) or Fprint(f) etc.
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// to generate its output.
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type Formatter interface {
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Format(f State, c rune)
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}
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// Stringer is implemented by any value that has a String method,
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// which defines the ``native'' format for that value.
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// The String method is used to print values passed as an operand
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// to any format that accepts a string or to an unformatted printer
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// such as Print.
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type Stringer interface {
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String() string
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}
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// GoStringer is implemented by any value that has a GoString method,
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// which defines the Go syntax for that value.
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// The GoString method is used to print values passed as an operand
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// to a %#v format.
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type GoStringer interface {
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GoString() string
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}
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// Use simple []byte instead of bytes.Buffer to avoid large dependency.
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type buffer []byte
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func (b *buffer) Write(p []byte) (n int, err error) {
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*b = append(*b, p...)
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return len(p), nil
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}
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func (b *buffer) WriteString(s string) (n int, err error) {
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*b = append(*b, s...)
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return len(s), nil
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}
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func (b *buffer) WriteByte(c byte) error {
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*b = append(*b, c)
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return nil
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}
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func (bp *buffer) WriteRune(r rune) error {
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if r < utf8.RuneSelf {
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*bp = append(*bp, byte(r))
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return nil
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}
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b := *bp
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n := len(b)
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for n+utf8.UTFMax > cap(b) {
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b = append(b, 0)
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}
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w := utf8.EncodeRune(b[n:n+utf8.UTFMax], r)
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*bp = b[:n+w]
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return nil
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}
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type pp struct {
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n int
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panicking bool
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erroring bool // printing an error condition
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buf buffer
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// field holds the current item, as an interface{}.
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field interface{}
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// value holds the current item, as a reflect.Value, and will be
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// the zero Value if the item has not been reflected.
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value reflect.Value
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runeBuf [utf8.UTFMax]byte
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fmt fmt
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}
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// A cache holds a set of reusable objects.
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// The slice is a stack (LIFO).
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// If more are needed, the cache creates them by calling new.
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type cache struct {
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mu sync.Mutex
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saved []interface{}
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new func() interface{}
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}
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func (c *cache) put(x interface{}) {
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c.mu.Lock()
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if len(c.saved) < cap(c.saved) {
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c.saved = append(c.saved, x)
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}
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c.mu.Unlock()
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}
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func (c *cache) get() interface{} {
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c.mu.Lock()
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n := len(c.saved)
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if n == 0 {
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c.mu.Unlock()
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return c.new()
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}
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x := c.saved[n-1]
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c.saved = c.saved[0 : n-1]
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c.mu.Unlock()
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return x
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}
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func newCache(f func() interface{}) *cache {
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return &cache{saved: make([]interface{}, 0, 100), new: f}
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}
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var ppFree = newCache(func() interface{} { return new(pp) })
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// newPrinter allocates a new pp struct or grab a cached one.
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func newPrinter() *pp {
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p := ppFree.get().(*pp)
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p.panicking = false
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p.erroring = false
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p.fmt.init(&p.buf)
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return p
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}
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// free saves used pp structs in ppFree; avoids an allocation per invocation.
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func (p *pp) free() {
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// Don't hold on to pp structs with large buffers.
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if cap(p.buf) > 1024 {
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return
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}
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p.buf = p.buf[:0]
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p.field = nil
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p.value = reflect.Value{}
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ppFree.put(p)
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}
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func (p *pp) Width() (wid int, ok bool) { return p.fmt.wid, p.fmt.widPresent }
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func (p *pp) Precision() (prec int, ok bool) { return p.fmt.prec, p.fmt.precPresent }
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func (p *pp) Flag(b int) bool {
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switch b {
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case '-':
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return p.fmt.minus
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case '+':
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return p.fmt.plus
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case '#':
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return p.fmt.sharp
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case ' ':
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return p.fmt.space
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case '0':
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return p.fmt.zero
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}
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return false
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}
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func (p *pp) add(c rune) {
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p.buf.WriteRune(c)
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}
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// Implement Write so we can call Fprintf on a pp (through State), for
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// recursive use in custom verbs.
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func (p *pp) Write(b []byte) (ret int, err error) {
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return p.buf.Write(b)
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}
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// These routines end in 'f' and take a format string.
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// Fprintf formats according to a format specifier and writes to w.
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// It returns the number of bytes written and any write error encountered.
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func Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) {
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p := newPrinter()
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p.doPrintf(format, a)
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n64, err := w.Write(p.buf)
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p.free()
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return int(n64), err
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}
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// Printf formats according to a format specifier and writes to standard output.
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// It returns the number of bytes written and any write error encountered.
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func Printf(format string, a ...interface{}) (n int, err error) {
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return Fprintf(os.Stdout, format, a...)
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}
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// Sprintf formats according to a format specifier and returns the resulting string.
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func Sprintf(format string, a ...interface{}) string {
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p := newPrinter()
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p.doPrintf(format, a)
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s := string(p.buf)
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p.free()
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return s
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}
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// Errorf formats according to a format specifier and returns the string
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// as a value that satisfies error.
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func Errorf(format string, a ...interface{}) error {
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return errors.New(Sprintf(format, a...))
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}
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// These routines do not take a format string
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// Fprint formats using the default formats for its operands and writes to w.
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// Spaces are added between operands when neither is a string.
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// It returns the number of bytes written and any write error encountered.
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func Fprint(w io.Writer, a ...interface{}) (n int, err error) {
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p := newPrinter()
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p.doPrint(a, false, false)
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n64, err := w.Write(p.buf)
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p.free()
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return int(n64), err
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}
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// Print formats using the default formats for its operands and writes to standard output.
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// Spaces are added between operands when neither is a string.
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// It returns the number of bytes written and any write error encountered.
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func Print(a ...interface{}) (n int, err error) {
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return Fprint(os.Stdout, a...)
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}
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// Sprint formats using the default formats for its operands and returns the resulting string.
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// Spaces are added between operands when neither is a string.
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func Sprint(a ...interface{}) string {
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p := newPrinter()
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p.doPrint(a, false, false)
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s := string(p.buf)
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p.free()
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return s
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}
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// These routines end in 'ln', do not take a format string,
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// always add spaces between operands, and add a newline
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// after the last operand.
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// Fprintln formats using the default formats for its operands and writes to w.
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// Spaces are always added between operands and a newline is appended.
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// It returns the number of bytes written and any write error encountered.
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func Fprintln(w io.Writer, a ...interface{}) (n int, err error) {
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p := newPrinter()
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p.doPrint(a, true, true)
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n64, err := w.Write(p.buf)
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p.free()
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return int(n64), err
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}
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// Println formats using the default formats for its operands and writes to standard output.
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// Spaces are always added between operands and a newline is appended.
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// It returns the number of bytes written and any write error encountered.
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func Println(a ...interface{}) (n int, err error) {
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return Fprintln(os.Stdout, a...)
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}
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// Sprintln formats using the default formats for its operands and returns the resulting string.
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// Spaces are always added between operands and a newline is appended.
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func Sprintln(a ...interface{}) string {
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p := newPrinter()
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p.doPrint(a, true, true)
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s := string(p.buf)
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p.free()
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return s
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}
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// getField gets the i'th arg of the struct value.
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// If the arg itself is an interface, return a value for
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// the thing inside the interface, not the interface itself.
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func getField(v reflect.Value, i int) reflect.Value {
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val := v.Field(i)
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if val.Kind() == reflect.Interface && !val.IsNil() {
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val = val.Elem()
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}
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return val
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}
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// parsenum converts ASCII to integer. num is 0 (and isnum is false) if no number present.
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func parsenum(s string, start, end int) (num int, isnum bool, newi int) {
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if start >= end {
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return 0, false, end
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}
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for newi = start; newi < end && '0' <= s[newi] && s[newi] <= '9'; newi++ {
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num = num*10 + int(s[newi]-'0')
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isnum = true
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}
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return
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}
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func (p *pp) unknownType(v interface{}) {
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if v == nil {
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p.buf.Write(nilAngleBytes)
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return
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}
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p.buf.WriteByte('?')
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p.buf.WriteString(reflect.TypeOf(v).String())
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p.buf.WriteByte('?')
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}
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func (p *pp) badVerb(verb rune) {
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p.erroring = true
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p.add('%')
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p.add('!')
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p.add(verb)
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p.add('(')
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switch {
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case p.field != nil:
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p.buf.WriteString(reflect.TypeOf(p.field).String())
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p.add('=')
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p.printField(p.field, 'v', false, false, 0)
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case p.value.IsValid():
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p.buf.WriteString(p.value.Type().String())
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p.add('=')
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p.printValue(p.value, 'v', false, false, 0)
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default:
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p.buf.Write(nilAngleBytes)
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}
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p.add(')')
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p.erroring = false
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}
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func (p *pp) fmtBool(v bool, verb rune) {
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switch verb {
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case 't', 'v':
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p.fmt.fmt_boolean(v)
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default:
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p.badVerb(verb)
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}
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}
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// fmtC formats a rune for the 'c' format.
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func (p *pp) fmtC(c int64) {
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r := rune(c) // Check for overflow.
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if int64(r) != c {
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r = utf8.RuneError
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}
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w := utf8.EncodeRune(p.runeBuf[0:utf8.UTFMax], r)
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p.fmt.pad(p.runeBuf[0:w])
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}
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func (p *pp) fmtInt64(v int64, verb rune) {
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switch verb {
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case 'b':
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p.fmt.integer(v, 2, signed, ldigits)
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case 'c':
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p.fmtC(v)
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case 'd', 'v':
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p.fmt.integer(v, 10, signed, ldigits)
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case 'o':
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p.fmt.integer(v, 8, signed, ldigits)
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case 'q':
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if 0 <= v && v <= utf8.MaxRune {
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p.fmt.fmt_qc(v)
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} else {
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p.badVerb(verb)
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}
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case 'x':
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p.fmt.integer(v, 16, signed, ldigits)
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case 'U':
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p.fmtUnicode(v)
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case 'X':
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p.fmt.integer(v, 16, signed, udigits)
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default:
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p.badVerb(verb)
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}
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}
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// fmt0x64 formats a uint64 in hexadecimal and prefixes it with 0x or
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// not, as requested, by temporarily setting the sharp flag.
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func (p *pp) fmt0x64(v uint64, leading0x bool) {
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sharp := p.fmt.sharp
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p.fmt.sharp = leading0x
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p.fmt.integer(int64(v), 16, unsigned, ldigits)
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p.fmt.sharp = sharp
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}
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// fmtUnicode formats a uint64 in U+1234 form by
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// temporarily turning on the unicode flag and tweaking the precision.
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func (p *pp) fmtUnicode(v int64) {
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precPresent := p.fmt.precPresent
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sharp := p.fmt.sharp
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p.fmt.sharp = false
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prec := p.fmt.prec
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if !precPresent {
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// If prec is already set, leave it alone; otherwise 4 is minimum.
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p.fmt.prec = 4
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p.fmt.precPresent = true
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}
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p.fmt.unicode = true // turn on U+
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p.fmt.uniQuote = sharp
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p.fmt.integer(int64(v), 16, unsigned, udigits)
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p.fmt.unicode = false
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p.fmt.uniQuote = false
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p.fmt.prec = prec
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p.fmt.precPresent = precPresent
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p.fmt.sharp = sharp
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}
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func (p *pp) fmtUint64(v uint64, verb rune, goSyntax bool) {
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switch verb {
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case 'b':
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p.fmt.integer(int64(v), 2, unsigned, ldigits)
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case 'c':
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p.fmtC(int64(v))
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case 'd':
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p.fmt.integer(int64(v), 10, unsigned, ldigits)
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case 'v':
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if goSyntax {
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p.fmt0x64(v, true)
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} else {
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p.fmt.integer(int64(v), 10, unsigned, ldigits)
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}
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case 'o':
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p.fmt.integer(int64(v), 8, unsigned, ldigits)
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case 'q':
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if 0 <= v && v <= utf8.MaxRune {
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p.fmt.fmt_qc(int64(v))
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} else {
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p.badVerb(verb)
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}
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case 'x':
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p.fmt.integer(int64(v), 16, unsigned, ldigits)
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case 'X':
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p.fmt.integer(int64(v), 16, unsigned, udigits)
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case 'U':
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p.fmtUnicode(int64(v))
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default:
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p.badVerb(verb)
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}
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}
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func (p *pp) fmtFloat32(v float32, verb rune) {
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switch verb {
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case 'b':
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p.fmt.fmt_fb32(v)
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case 'e':
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p.fmt.fmt_e32(v)
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case 'E':
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p.fmt.fmt_E32(v)
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case 'f':
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p.fmt.fmt_f32(v)
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case 'g', 'v':
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p.fmt.fmt_g32(v)
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case 'G':
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p.fmt.fmt_G32(v)
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default:
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p.badVerb(verb)
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}
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}
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func (p *pp) fmtFloat64(v float64, verb rune) {
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switch verb {
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case 'b':
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p.fmt.fmt_fb64(v)
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case 'e':
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p.fmt.fmt_e64(v)
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case 'E':
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p.fmt.fmt_E64(v)
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case 'f':
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p.fmt.fmt_f64(v)
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case 'g', 'v':
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p.fmt.fmt_g64(v)
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case 'G':
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p.fmt.fmt_G64(v)
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default:
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p.badVerb(verb)
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}
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}
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func (p *pp) fmtComplex64(v complex64, verb rune) {
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switch verb {
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case 'e', 'E', 'f', 'F', 'g', 'G':
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p.fmt.fmt_c64(v, verb)
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case 'v':
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p.fmt.fmt_c64(v, 'g')
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default:
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p.badVerb(verb)
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}
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}
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func (p *pp) fmtComplex128(v complex128, verb rune) {
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switch verb {
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case 'e', 'E', 'f', 'F', 'g', 'G':
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p.fmt.fmt_c128(v, verb)
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case 'v':
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p.fmt.fmt_c128(v, 'g')
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default:
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p.badVerb(verb)
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}
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}
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|
|
func (p *pp) fmtString(v string, verb rune, goSyntax bool) {
|
|
switch verb {
|
|
case 'v':
|
|
if goSyntax {
|
|
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 *pp) fmtBytes(v []byte, verb rune, goSyntax bool, typ reflect.Type, depth int) {
|
|
if verb == 'v' || verb == 'd' {
|
|
if goSyntax {
|
|
if typ == nil {
|
|
p.buf.Write(bytesBytes)
|
|
} else {
|
|
p.buf.WriteString(typ.String())
|
|
p.buf.WriteByte('{')
|
|
}
|
|
} else {
|
|
p.buf.WriteByte('[')
|
|
}
|
|
for i, c := range v {
|
|
if i > 0 {
|
|
if goSyntax {
|
|
p.buf.Write(commaSpaceBytes)
|
|
} else {
|
|
p.buf.WriteByte(' ')
|
|
}
|
|
}
|
|
p.printField(c, 'v', p.fmt.plus, goSyntax, depth+1)
|
|
}
|
|
if goSyntax {
|
|
p.buf.WriteByte('}')
|
|
} else {
|
|
p.buf.WriteByte(']')
|
|
}
|
|
return
|
|
}
|
|
switch verb {
|
|
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.badVerb(verb)
|
|
}
|
|
}
|
|
|
|
func (p *pp) fmtPointer(value reflect.Value, verb rune, goSyntax bool) {
|
|
use0x64 := true
|
|
switch verb {
|
|
case 'p', 'v':
|
|
// ok
|
|
case 'b', 'd', 'o', 'x', 'X':
|
|
use0x64 = false
|
|
// ok
|
|
default:
|
|
p.badVerb(verb)
|
|
return
|
|
}
|
|
|
|
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
|
|
}
|
|
|
|
if goSyntax {
|
|
p.add('(')
|
|
p.buf.WriteString(value.Type().String())
|
|
p.add(')')
|
|
p.add('(')
|
|
if u == 0 {
|
|
p.buf.Write(nilBytes)
|
|
} else {
|
|
p.fmt0x64(uint64(u), true)
|
|
}
|
|
p.add(')')
|
|
} else if verb == 'v' && u == 0 {
|
|
p.buf.Write(nilAngleBytes)
|
|
} else {
|
|
if use0x64 {
|
|
p.fmt0x64(uint64(u), !p.fmt.sharp)
|
|
} else {
|
|
p.fmtUint64(uint64(u), verb, false)
|
|
}
|
|
}
|
|
}
|
|
|
|
var (
|
|
intBits = reflect.TypeOf(0).Bits()
|
|
floatBits = reflect.TypeOf(0.0).Bits()
|
|
complexBits = reflect.TypeOf(1i).Bits()
|
|
uintptrBits = reflect.TypeOf(uintptr(0)).Bits()
|
|
)
|
|
|
|
func (p *pp) catchPanic(field 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(field); v.Kind() == reflect.Ptr && v.IsNil() {
|
|
p.buf.Write(nilAngleBytes)
|
|
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 printField cannot succeed.
|
|
panic(err)
|
|
}
|
|
p.buf.WriteByte('%')
|
|
p.add(verb)
|
|
p.buf.Write(panicBytes)
|
|
p.panicking = true
|
|
p.printField(err, 'v', false, false, 0)
|
|
p.panicking = false
|
|
p.buf.WriteByte(')')
|
|
}
|
|
}
|
|
|
|
func (p *pp) handleMethods(verb rune, plus, goSyntax bool, depth int) (wasString, handled bool) {
|
|
if p.erroring {
|
|
return
|
|
}
|
|
// Is it a Formatter?
|
|
if formatter, ok := p.field.(Formatter); ok {
|
|
handled = true
|
|
wasString = false
|
|
defer p.catchPanic(p.field, verb)
|
|
formatter.Format(p, verb)
|
|
return
|
|
}
|
|
// Must not touch flags before Formatter looks at them.
|
|
if plus {
|
|
p.fmt.plus = false
|
|
}
|
|
|
|
// If we're doing Go syntax and the field knows how to supply it, take care of it now.
|
|
if goSyntax {
|
|
p.fmt.sharp = false
|
|
if stringer, ok := p.field.(GoStringer); ok {
|
|
wasString = false
|
|
handled = true
|
|
defer p.catchPanic(p.field, verb)
|
|
// Print the result of GoString unadorned.
|
|
p.fmtString(stringer.GoString(), 's', false)
|
|
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 wasString and handled, and deferring catchPanic,
|
|
// must happen before calling the method.
|
|
switch v := p.field.(type) {
|
|
case error:
|
|
wasString = false
|
|
handled = true
|
|
defer p.catchPanic(p.field, verb)
|
|
p.printField(v.Error(), verb, plus, false, depth)
|
|
return
|
|
|
|
case Stringer:
|
|
wasString = false
|
|
handled = true
|
|
defer p.catchPanic(p.field, verb)
|
|
p.printField(v.String(), verb, plus, false, depth)
|
|
return
|
|
}
|
|
}
|
|
}
|
|
handled = false
|
|
return
|
|
}
|
|
|
|
func (p *pp) printField(field interface{}, verb rune, plus, goSyntax bool, depth int) (wasString bool) {
|
|
p.field = field
|
|
p.value = reflect.Value{}
|
|
|
|
if field == nil {
|
|
if verb == 'T' || verb == 'v' {
|
|
p.fmt.pad(nilAngleBytes)
|
|
} else {
|
|
p.badVerb(verb)
|
|
}
|
|
return false
|
|
}
|
|
|
|
// Special processing considerations.
|
|
// %T (the value's type) and %p (its address) are special; we always do them first.
|
|
switch verb {
|
|
case 'T':
|
|
p.printField(reflect.TypeOf(field).String(), 's', false, false, 0)
|
|
return false
|
|
case 'p':
|
|
p.fmtPointer(reflect.ValueOf(field), verb, goSyntax)
|
|
return false
|
|
}
|
|
|
|
// Clear flags for base formatters.
|
|
// handleMethods needs them, so we must restore them later.
|
|
// We could call handleMethods here and avoid this work, but
|
|
// handleMethods is expensive enough to be worth delaying.
|
|
oldPlus := p.fmt.plus
|
|
oldSharp := p.fmt.sharp
|
|
if plus {
|
|
p.fmt.plus = false
|
|
}
|
|
if goSyntax {
|
|
p.fmt.sharp = false
|
|
}
|
|
|
|
// Some types can be done without reflection.
|
|
switch f := field.(type) {
|
|
case bool:
|
|
p.fmtBool(f, verb)
|
|
case float32:
|
|
p.fmtFloat32(f, verb)
|
|
case float64:
|
|
p.fmtFloat64(f, verb)
|
|
case complex64:
|
|
p.fmtComplex64(complex64(f), verb)
|
|
case complex128:
|
|
p.fmtComplex128(f, verb)
|
|
case int:
|
|
p.fmtInt64(int64(f), verb)
|
|
case int8:
|
|
p.fmtInt64(int64(f), verb)
|
|
case int16:
|
|
p.fmtInt64(int64(f), verb)
|
|
case int32:
|
|
p.fmtInt64(int64(f), verb)
|
|
case int64:
|
|
p.fmtInt64(f, verb)
|
|
case uint:
|
|
p.fmtUint64(uint64(f), verb, goSyntax)
|
|
case uint8:
|
|
p.fmtUint64(uint64(f), verb, goSyntax)
|
|
case uint16:
|
|
p.fmtUint64(uint64(f), verb, goSyntax)
|
|
case uint32:
|
|
p.fmtUint64(uint64(f), verb, goSyntax)
|
|
case uint64:
|
|
p.fmtUint64(f, verb, goSyntax)
|
|
case uintptr:
|
|
p.fmtUint64(uint64(f), verb, goSyntax)
|
|
case string:
|
|
p.fmtString(f, verb, goSyntax)
|
|
wasString = verb == 's' || verb == 'v'
|
|
case []byte:
|
|
p.fmtBytes(f, verb, goSyntax, nil, depth)
|
|
wasString = verb == 's'
|
|
default:
|
|
// Restore flags in case handleMethods finds a Formatter.
|
|
p.fmt.plus = oldPlus
|
|
p.fmt.sharp = oldSharp
|
|
// If the type is not simple, it might have methods.
|
|
if wasString, handled := p.handleMethods(verb, plus, goSyntax, depth); handled {
|
|
return wasString
|
|
}
|
|
// Need to use reflection
|
|
return p.printReflectValue(reflect.ValueOf(field), verb, plus, goSyntax, depth)
|
|
}
|
|
p.field = nil
|
|
return
|
|
}
|
|
|
|
// printValue is like printField but starts with a reflect value, not an interface{} value.
|
|
func (p *pp) printValue(value reflect.Value, verb rune, plus, goSyntax bool, depth int) (wasString bool) {
|
|
if !value.IsValid() {
|
|
if verb == 'T' || verb == 'v' {
|
|
p.buf.Write(nilAngleBytes)
|
|
} else {
|
|
p.badVerb(verb)
|
|
}
|
|
return false
|
|
}
|
|
|
|
// Special processing considerations.
|
|
// %T (the value's type) and %p (its address) are special; we always do them first.
|
|
switch verb {
|
|
case 'T':
|
|
p.printField(value.Type().String(), 's', false, false, 0)
|
|
return false
|
|
case 'p':
|
|
p.fmtPointer(value, verb, goSyntax)
|
|
return false
|
|
}
|
|
|
|
// Handle values with special methods.
|
|
// Call always, even when field == nil, because handleMethods clears p.fmt.plus for us.
|
|
p.field = nil // Make sure it's cleared, for safety.
|
|
if value.CanInterface() {
|
|
p.field = value.Interface()
|
|
}
|
|
if wasString, handled := p.handleMethods(verb, plus, goSyntax, depth); handled {
|
|
return wasString
|
|
}
|
|
|
|
return p.printReflectValue(value, verb, plus, goSyntax, depth)
|
|
}
|
|
|
|
// printReflectValue is the fallback for both printField and printValue.
|
|
// It uses reflect to print the value.
|
|
func (p *pp) printReflectValue(value reflect.Value, verb rune, plus, goSyntax bool, depth int) (wasString bool) {
|
|
oldValue := p.value
|
|
p.value = value
|
|
BigSwitch:
|
|
switch f := value; f.Kind() {
|
|
case reflect.Bool:
|
|
p.fmtBool(f.Bool(), verb)
|
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
|
p.fmtInt64(f.Int(), verb)
|
|
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
|
|
p.fmtUint64(uint64(f.Uint()), verb, goSyntax)
|
|
case reflect.Float32, reflect.Float64:
|
|
if f.Type().Size() == 4 {
|
|
p.fmtFloat32(float32(f.Float()), verb)
|
|
} else {
|
|
p.fmtFloat64(float64(f.Float()), verb)
|
|
}
|
|
case reflect.Complex64, reflect.Complex128:
|
|
if f.Type().Size() == 8 {
|
|
p.fmtComplex64(complex64(f.Complex()), verb)
|
|
} else {
|
|
p.fmtComplex128(complex128(f.Complex()), verb)
|
|
}
|
|
case reflect.String:
|
|
p.fmtString(f.String(), verb, goSyntax)
|
|
case reflect.Map:
|
|
if goSyntax {
|
|
p.buf.WriteString(f.Type().String())
|
|
if f.IsNil() {
|
|
p.buf.WriteString("(nil)")
|
|
break
|
|
}
|
|
p.buf.WriteByte('{')
|
|
} else {
|
|
p.buf.Write(mapBytes)
|
|
}
|
|
keys := f.MapKeys()
|
|
for i, key := range keys {
|
|
if i > 0 {
|
|
if goSyntax {
|
|
p.buf.Write(commaSpaceBytes)
|
|
} else {
|
|
p.buf.WriteByte(' ')
|
|
}
|
|
}
|
|
p.printValue(key, verb, plus, goSyntax, depth+1)
|
|
p.buf.WriteByte(':')
|
|
p.printValue(f.MapIndex(key), verb, plus, goSyntax, depth+1)
|
|
}
|
|
if goSyntax {
|
|
p.buf.WriteByte('}')
|
|
} else {
|
|
p.buf.WriteByte(']')
|
|
}
|
|
case reflect.Struct:
|
|
if goSyntax {
|
|
p.buf.WriteString(value.Type().String())
|
|
}
|
|
p.add('{')
|
|
v := f
|
|
t := v.Type()
|
|
for i := 0; i < v.NumField(); i++ {
|
|
if i > 0 {
|
|
if goSyntax {
|
|
p.buf.Write(commaSpaceBytes)
|
|
} else {
|
|
p.buf.WriteByte(' ')
|
|
}
|
|
}
|
|
if plus || goSyntax {
|
|
if f := t.Field(i); f.Name != "" {
|
|
p.buf.WriteString(f.Name)
|
|
p.buf.WriteByte(':')
|
|
}
|
|
}
|
|
p.printValue(getField(v, i), verb, plus, goSyntax, depth+1)
|
|
}
|
|
p.buf.WriteByte('}')
|
|
case reflect.Interface:
|
|
value := f.Elem()
|
|
if !value.IsValid() {
|
|
if goSyntax {
|
|
p.buf.WriteString(f.Type().String())
|
|
p.buf.Write(nilParenBytes)
|
|
} else {
|
|
p.buf.Write(nilAngleBytes)
|
|
}
|
|
} else {
|
|
wasString = p.printValue(value, verb, plus, goSyntax, depth+1)
|
|
}
|
|
case reflect.Array, reflect.Slice:
|
|
// Byte slices are special.
|
|
if typ := f.Type(); typ.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, goSyntax, typ, depth)
|
|
wasString = verb == 's'
|
|
break
|
|
}
|
|
if goSyntax {
|
|
p.buf.WriteString(value.Type().String())
|
|
if f.Kind() == reflect.Slice && f.IsNil() {
|
|
p.buf.WriteString("(nil)")
|
|
break
|
|
}
|
|
p.buf.WriteByte('{')
|
|
} else {
|
|
p.buf.WriteByte('[')
|
|
}
|
|
for i := 0; i < f.Len(); i++ {
|
|
if i > 0 {
|
|
if goSyntax {
|
|
p.buf.Write(commaSpaceBytes)
|
|
} else {
|
|
p.buf.WriteByte(' ')
|
|
}
|
|
}
|
|
p.printValue(f.Index(i), verb, plus, goSyntax, depth+1)
|
|
}
|
|
if goSyntax {
|
|
p.buf.WriteByte('}')
|
|
} else {
|
|
p.buf.WriteByte(']')
|
|
}
|
|
case reflect.Ptr:
|
|
v := f.Pointer()
|
|
// pointer to array or slice or struct? ok at top level
|
|
// but not embedded (avoid loops)
|
|
if v != 0 && depth == 0 {
|
|
switch a := f.Elem(); a.Kind() {
|
|
case reflect.Array, reflect.Slice:
|
|
p.buf.WriteByte('&')
|
|
p.printValue(a, verb, plus, goSyntax, depth+1)
|
|
break BigSwitch
|
|
case reflect.Struct:
|
|
p.buf.WriteByte('&')
|
|
p.printValue(a, verb, plus, goSyntax, depth+1)
|
|
break BigSwitch
|
|
}
|
|
}
|
|
fallthrough
|
|
case reflect.Chan, reflect.Func, reflect.UnsafePointer:
|
|
p.fmtPointer(value, verb, goSyntax)
|
|
default:
|
|
p.unknownType(f)
|
|
}
|
|
p.value = oldValue
|
|
return wasString
|
|
}
|
|
|
|
// intFromArg gets the fieldnumth element of a. On return, isInt reports whether the argument has type int.
|
|
func intFromArg(a []interface{}, end, i, fieldnum int) (num int, isInt bool, newi, newfieldnum int) {
|
|
newi, newfieldnum = end, fieldnum
|
|
if i < end && fieldnum < len(a) {
|
|
num, isInt = a[fieldnum].(int)
|
|
newi, newfieldnum = i+1, fieldnum+1
|
|
}
|
|
return
|
|
}
|
|
|
|
func (p *pp) doPrintf(format string, a []interface{}) {
|
|
end := len(format)
|
|
fieldnum := 0 // we process one field per non-trivial format
|
|
for i := 0; i < end; {
|
|
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++
|
|
// flags and widths
|
|
p.fmt.clearflags()
|
|
F:
|
|
for ; i < end; i++ {
|
|
switch format[i] {
|
|
case '#':
|
|
p.fmt.sharp = true
|
|
case '0':
|
|
p.fmt.zero = true
|
|
case '+':
|
|
p.fmt.plus = true
|
|
case '-':
|
|
p.fmt.minus = true
|
|
case ' ':
|
|
p.fmt.space = true
|
|
default:
|
|
break F
|
|
}
|
|
}
|
|
// do we have width?
|
|
if i < end && format[i] == '*' {
|
|
p.fmt.wid, p.fmt.widPresent, i, fieldnum = intFromArg(a, end, i, fieldnum)
|
|
if !p.fmt.widPresent {
|
|
p.buf.Write(badWidthBytes)
|
|
}
|
|
} else {
|
|
p.fmt.wid, p.fmt.widPresent, i = parsenum(format, i, end)
|
|
}
|
|
// do we have precision?
|
|
if i+1 < end && format[i] == '.' {
|
|
if format[i+1] == '*' {
|
|
p.fmt.prec, p.fmt.precPresent, i, fieldnum = intFromArg(a, end, i+1, fieldnum)
|
|
if !p.fmt.precPresent {
|
|
p.buf.Write(badPrecBytes)
|
|
}
|
|
} else {
|
|
p.fmt.prec, p.fmt.precPresent, i = parsenum(format, i+1, end)
|
|
if !p.fmt.precPresent {
|
|
p.fmt.prec = 0
|
|
p.fmt.precPresent = true
|
|
}
|
|
}
|
|
}
|
|
if i >= end {
|
|
p.buf.Write(noVerbBytes)
|
|
continue
|
|
}
|
|
c, w := utf8.DecodeRuneInString(format[i:])
|
|
i += w
|
|
// percent is special - absorbs no operand
|
|
if c == '%' {
|
|
p.buf.WriteByte('%') // We ignore width and prec.
|
|
continue
|
|
}
|
|
if fieldnum >= len(a) { // out of operands
|
|
p.buf.WriteByte('%')
|
|
p.add(c)
|
|
p.buf.Write(missingBytes)
|
|
continue
|
|
}
|
|
field := a[fieldnum]
|
|
fieldnum++
|
|
|
|
goSyntax := c == 'v' && p.fmt.sharp
|
|
plus := c == 'v' && p.fmt.plus
|
|
p.printField(field, c, plus, goSyntax, 0)
|
|
}
|
|
|
|
if fieldnum < len(a) {
|
|
p.buf.Write(extraBytes)
|
|
for ; fieldnum < len(a); fieldnum++ {
|
|
field := a[fieldnum]
|
|
if field != nil {
|
|
p.buf.WriteString(reflect.TypeOf(field).String())
|
|
p.buf.WriteByte('=')
|
|
}
|
|
p.printField(field, 'v', false, false, 0)
|
|
if fieldnum+1 < len(a) {
|
|
p.buf.Write(commaSpaceBytes)
|
|
}
|
|
}
|
|
p.buf.WriteByte(')')
|
|
}
|
|
}
|
|
|
|
func (p *pp) doPrint(a []interface{}, addspace, addnewline bool) {
|
|
prevString := false
|
|
for fieldnum := 0; fieldnum < len(a); fieldnum++ {
|
|
p.fmt.clearflags()
|
|
// always add spaces if we're doing Println
|
|
field := a[fieldnum]
|
|
if fieldnum > 0 {
|
|
isString := field != nil && reflect.TypeOf(field).Kind() == reflect.String
|
|
if addspace || !isString && !prevString {
|
|
p.buf.WriteByte(' ')
|
|
}
|
|
}
|
|
prevString = p.printField(field, 'v', false, false, 0)
|
|
}
|
|
if addnewline {
|
|
p.buf.WriteByte('\n')
|
|
}
|
|
}
|