( strings being sent to parse routines are always null
  terminated )

: _pc ( a -- n f, parse character )
    ( apostrophe is ASCII 39 )
    DUP 1+ C@ 39 = OVER 3 + C@ 39 = AND  ( a f )
    NOT IF 0 EXIT THEN   ( a 0 )
    ( surrounded by apos, good, return )
    2+ C@ 1                             ( n 1 )
;