package key

// ----------------------------------------------------------------------------
// !Terminal Input Escape Code Sequences
// ----------------------------------------------------------------------------

const (
	Backspace = '\x7f'
	Esc       = '\x1b'
	Enter     = '\r'
)

// Is this an ASCII character?
func IsAscii(char rune) bool {
	return char < 0x80
}

// Is this an ASCII ctrl character?
func IsCtrl(char rune) bool {
	if !IsAscii(char) {
		return false
	}

	return char == 0x7f || char < 0x20
}

// Return the input code of a Ctrl-key chord.
func Ctrl(char rune) rune {
	if !IsAscii(char) {
		return 0
	}

	ch := char & 0x1f

	return ch
}