In exercise 8.6 the characters
^^M are defined to belong to categories 0, 7, 10, and 11 respectively. The question ist what tokens are produced from the input line
‘^^B^^BM^^A^^B^^C^^M^^@\M ’ (There is a space character after M). As a hint Knuth states that the line is followed by
<return>, which is
^^M; and that ^^@ denotes the
null character, which has category 9.
Why isn't the space character after the control symbol
^^B ignored? Why does it not matter for the last control sequence that
^^M has category code 11?
Can anyone explain that to me, please?