func()

in errors/fmt/print.go [678:845]

• 160 lines of code
• 52 McCabe index (conditional complexity)

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)
		}
		keys := f.MapKeys()
		for i, key := range keys {
			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(f.MapIndex(key), 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.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.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)
	}
}