m4: Quoted strings

1 
1 3.2 Quoting input to 'm4'
1 =========================
1 
1 A quoted string is a sequence of characters surrounded by quote strings,
1 defaulting to '`' and ''', where the nested begin and end quotes within
1 the string are balanced.  The value of a string token is the text, with
1 one level of quotes stripped off.  Thus
1 
1      `'
1      =>
1 
1 is the empty string, and double-quoting turns into single-quoting.
1 
1      ``quoted''
1      =>`quoted'
1 
1    The quote characters can be changed at any time, using the builtin
1 macro 'changequote'.  ⇒Changequote, for more information.
1