// This file contains the code to check canonical methods.

package method

import "fmt"

type MethodTest int

func (t *MethodTest) Scan(x fmt.ScanState, c byte) { // ERROR "should have signature Scan\(fmt\.ScanState, rune\) error"

// To do that, the arguments that have a = prefix are treated as
// signals that the canonical meaning is intended: if a Scan
// method doesn't have a fmt.ScanState as its first argument,
// we let it go. But if it does have a fmt.ScanState, then the
// rest has to match.
var canonicalMethods = map[string]struct{ args, results []string }{
	"As": {[]string{"any"}, []string{"bool"}}, // errors.As

	case '-':
		neg = true
	case '+':
		// nothing to do
	default:
		r.UnreadByte()
	}
	return
}

// byteReader is a local wrapper around fmt.ScanState;
// it implements the ByteReader interface.
type byteReader struct {
	fmt.ScanState
}

func (r byteReader) ReadByte() (byte, error) {
	ch, size, err := r.ReadRune()
	if size != 1 && err == nil {
		err = fmt.Errorf("invalid rune %#U", ch)
	}

// [fmt.Scan] for floating point values, which are:
// 'b' (binary), 'e', 'E', 'f', 'F', 'g' and 'G'.
// Scan doesn't handle ±Inf.
func (z *Float) Scan(s fmt.ScanState, ch rune) error {
	s.SkipSpace()
	_, _, err := z.scan(byteReader{s}, 0)
	return err