/tutorial/backtracking/tiny_prolog/prolog_parser.e

 1class PROLOG_PARSER creation make feature
 2   make(b: BASE) is do
 3      base := b
 4      state := 0
 5      create stack_of_states.with_capacity(10)
 6      end
 7   put_string(s: STRING) is local i:INTEGER do
 8      from i:=s.lower until i>s.upper loop
 9         put_character(s.item(i))
10	 i := i+1
11      end
12      end
13   put_character(c: CHARACTER) is do
14      inspect state
15      when 0 then
16      else
17      end
18      end
19   base: BASE
20   state: INTEGER
21   stack_of_states: FAST_ARRAY[like state]
22end