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1*16467b97STreehugger Robot/// \page using Using the ANTLR3 C Target
2*16467b97STreehugger Robot///
3*16467b97STreehugger Robot/// \section intro Introduction
4*16467b97STreehugger Robot///
5*16467b97STreehugger Robot/// Using the ANTLR target involves gaining knowledge of a number of elements:
6*16467b97STreehugger Robot///
7*16467b97STreehugger Robot/// -# Writing ANTLR grammars (not covered in this manual);
8*16467b97STreehugger Robot/// -# How ANTLR works (not covered in this manual);
9*16467b97STreehugger Robot/// -# How to use the \@sections with the C target
10*16467b97STreehugger Robot/// -# Interoperation with the runtime within rule actions;
11*16467b97STreehugger Robot/// -# Implementing custom versions of the standard library methods;
12*16467b97STreehugger Robot///
13*16467b97STreehugger Robot/// If you are as yet unfamiliar with how ANTLR works in general, then
14*16467b97STreehugger Robot/// it is suggested that you read the various <a href="http://www.antlr.org/wiki">wiki pages</a> concerned with
15*16467b97STreehugger Robot/// getting started. However there are a few things that you should note:
16*16467b97STreehugger Robot///
17*16467b97STreehugger Robot/// - The lexer is independent of the parser. You \b cannot control the lexer from within the parser;
18*16467b97STreehugger Robot/// - The tree parser is independent of the parser. You \b cannot control the parser from within the tree parser(s);
19*16467b97STreehugger Robot/// - Each tree parser is independent of other tree parsers.
20*16467b97STreehugger Robot///
21*16467b97STreehugger Robot/// This means that your lexer runs first and consumes all the input stream until
22*16467b97STreehugger Robot/// you stop it programmatically, or it reaches the end of the input stream. It produces
23*16467b97STreehugger Robot/// a complete stream of tokens, which the parser then consumes.
24*16467b97STreehugger Robot///
25*16467b97STreehugger Robot/// \section Using \@sections in a C Targeted Grammar
26*16467b97STreehugger Robot///
27*16467b97STreehugger Robot/// Within a grammar file there are a number of special sections you can add that cause the
28*16467b97STreehugger Robot/// code within them to be placed at strategic points in the generated code such as
29*16467b97STreehugger Robot/// before or after the #include statements in the .c file, within the generated header file
30*16467b97STreehugger Robot/// or within the constructor for the recognizer.
31*16467b97STreehugger Robot///
32*16467b97STreehugger Robot/// Many of the \@sections used within a Java targeted grammar have some equivalent function within a
33*16467b97STreehugger Robot/// C targeted grammar, but their use may well be subtly different. There are also additional sections
34*16467b97STreehugger Robot/// that have meaning only within a grammar targeted for the C runtime.
35*16467b97STreehugger Robot///
36*16467b97STreehugger Robot/// Detailed documentation of these sections is given here: \subpage atsections
37*16467b97STreehugger Robot///
38*16467b97STreehugger Robot/// \section interop Interoperation Within Rule Actions
39*16467b97STreehugger Robot///
40*16467b97STreehugger Robot/// Rule actions have a limited number of elements they can access by name, independently of the
41*16467b97STreehugger Robot/// target language generated. These are elements such as $line, $pos, $text and so on. Where the
42*16467b97STreehugger Robot/// $xxx returns a basic type such as \c int, then you can use these in C as you would in the Java
43*16467b97STreehugger Robot/// target, but where a reference returns a string, you will get a pointer to the C runtime
44*16467b97STreehugger Robot/// string implementation #pANTLR3_STRING. This will give you access to things like token text
45*16467b97STreehugger Robot/// but also provides some convenience methods such as #pANTLR3_STRING->substring() and #pANTLR3_STRING->toUTF8().
46*16467b97STreehugger Robot///
47*16467b97STreehugger Robot/// The generated code provides a number of C MACROs, which make it easier to access runtime
48*16467b97STreehugger Robot/// components. Always use these macros when available, to protect your action code from changes
49*16467b97STreehugger Robot/// to the underlying implementation.
50*16467b97STreehugger Robot///
51*16467b97STreehugger Robot/// Detailed documentation of macros and rule action interoperation is given here: \subpage interop
52*16467b97STreehugger Robot///
53*16467b97STreehugger Robot/// \section Custom Implementing Customized Methods
54*16467b97STreehugger Robot///
55*16467b97STreehugger Robot/// Unless you wish to create your own tree structures using the built in ANTLR AST rewriting
56*16467b97STreehugger Robot/// notation, you will rarely need to override the default implementation of runtime methods. The
57*16467b97STreehugger Robot/// exception to this will be the syntax err reporting method, which is essentially a stub function
58*16467b97STreehugger Robot/// that you will usually want to provide your own implementation for. You should consider the built in function
59*16467b97STreehugger Robot/// displayRecognitionError() as an example of where to start as there can be no really useful
60*16467b97STreehugger Robot/// generic error message display.
61*16467b97STreehugger Robot///
62*16467b97STreehugger Robot///