/src/wrappers/glib/partially-implemented/iterator_on_utf8_string.e

 1class ITERATOR_ON_UTF8_STRING
 2	-- Iterator on UTF8 string.
 3
 4	-- 
 5inherit
 6	ITERATOR[UNICODE_CHARACTER]
 7
 8insert 
 9	GUNICODE_EXTERNALS
10	-- GUNICODE_MACROS
11
12creation {UTF8_STRING}
13	make
14
15feature {}
16	string: UTF8_STRING
17		-- The string to be traversed
18
19	pointer: POINTER
20		-- Current position
21feature {ANY}
22	make (s: UTF8_STRING) is
23		require
24			s /= Void
25		do
26			string := s
27			pointer := string.handle
28		ensure
29			string = s
30		end
31
32	start is
33		do
34			pointer := string.handle
35		end
36
37	is_off: BOOLEAN is
38		do
39			Result := pointer > string.handle + string.bytes_count
40		end
41
42	is_before: BOOLEAN is
43		-- Is Current off, before the beginning of the string?
44	do
45		Result := pointer < string.handle
46	end
47
48	item: UNICODE_CHARACTER is
49		do
50			Result.set(g_utf8_get_char(pointer))
51		end
52
53	next is
54		do
55			pointer := g_utf8_next_char (pointer)
56		end
57
58	prev is
59		-- Go backward.
60	local prev_ptr: POINTER
61	do
62		prev_ptr := g_utf8_prev_char(string.handle,pointer)
63		if prev_ptr.is_null then
64			-- no UTF-8 characters are presents before pointer in string. Set pointer to a something meaningful
65			pointer := pointer + (-1) 
66		end
67		--   g_utf8_find_prev_char ()
68
69		--  gchar*      g_utf8_find_prev_char           (const gchar *str,
70		--                                               const gchar *p);
71
72		--    Given a position p with a UTF-8 encoded string str, find the start of the
73		--    previous UTF-8 character starting before p. Returns NULL if no UTF-8 characters
74		--    are present in str before p.
75
76		--    p does not have to be at the beginning of a UTF-8 character. No check is made to
77		--    see if the character found is actually valid other than it starts with an
78		--    appropriate byte.
79
80		--    str :     pointer to the beginning of a UTF-8 encoded string
81		--    p :       pointer to some position within str
82		--    Returns : a pointer to the found character or NULL.
83	end
84end -- class ITERATOR_ON_UTF8_STRING