/tutorial/backtracking/tiny_parse/perser.e

 1class PARSER
 2inherit BACKTRACKING
 3feature
 4
 5	get_context: PARSER_CONTEXT is
 6		do
 7			Result.make(stack.count,position)
 8		end
 9
10	restore_context(ctxt: PARSER_CONTEXT) is
11		do
12			stack.resize(ctxt.depth)
13			position := ctxt.position
14		end
15
16	push_mark_begin(what: PARSER_PARSEABLE) is
17		local
18			mark: PARSER_MARK
19		do
20			mark.make_begin(position,what)
21			stack.add_last(mark)
22		end
23
24	push_mark_end(what: PARSER_PARSEABLE) is
25		local
26			mark: PARSER_MARK
27		do
28			mark.make_end(position,what)
29			stack.add_last(mark)
30		end
31
32	push_and_mark_end(what: PARSER_PARSEABLE) is
33		local
34			sequence: PARSER_SEQUENCE_MARK_END
35		do
36			sequence := pool_of_mark_end.get_instance
37			sequence.set_parseable(what)
38			push_sequence(sequence)
39		end
40
41	goto(what: PARSER_PARSEABLE) is
42		do
43			-- TODO bouffer les blancs
44			-- memoriser what
45		end
46	
47	goto_inside(what: PARSER_PARSEABLE) is
48		do
49			goto(what)
50			push_mark_begin(what)
51			push_and_mark_end(what)
52		end
53end
54