blob: 094c05531bce78e1ce013b7902a3ee39dfe59e68 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
Libcroco parser architecture
-----------------------------
Author: Dodji Seketeli <dodji@seketeli.org>
$Id$
I) Forethoughts.
===================
Libcroco's parser is a simple recursive descent parser.
The major design focus has been simplicity, reliability and
conformance.
Simplicity
-----------
We want the code to be maintainable by anyone who knows the css spec
and who knows how to code in C. Therefore, we avoid to overuse
the C preprocessor magic and all the tricks that tends to turn C into
a maintainance nightmare.
We also try to adhere to the gnome coding guidelines specified
at http://developer.gnome.org/doc/guides/programming-guidelines.
Reliability
-----------
Each single function of the libcroco library should never crash,
and this, whatever the arguments it takes.
As a consequence we tend to be paranoic when it comes to check
pointers values before dereferencing them for example...
Conformance
-----------
We try to stick to the css spec. We now this is almost impossible to achieve
given the ressource we have but we think it is sane target to chase.
II) Overall architecture
=========================
The parser is organized around two main classes :
1/ CRInput
2/ CRTknzr (Tokenizer or lexer)
3/ CRParser
II.1 The CRInput class
-----------------------
The CRInput class provides the abstraction of
an utf8-encoded character stream.
Ideally, it should abstracts local data sources
(local files and in-memory buffers)
and remote data sources (sockets, url-identified ressources) but at the
moment, it abstracts local data sources only.
Adding a new type of data source should be transparent for the
classes that already use CRInput. After all, it is what is abstraction about :)
II.2 The CRTknzr class
-------------------
The main job of the tokenizer (or lexer) is to
provide a get_next_token () method.
This methods returns the next css token found in the input stream.
(Note that the input stream here is an instance of CRInput).
This provides an extremely usefull facility to the parser.
II.3 The CRParser class
-------------------------
|
