src/antlr/TokenStreamSelector.cpp

/* ANTLR Translator Generator
 * Project led by Terence Parr at http://www.jGuru.com
 * Software rights: http://www.antlr.org/license.html
 *
 * $Id: TokenStreamSelector.cpp,v 1.1 2005-12-02 15:38:02 tim Exp $
 */
#include "antlr/TokenStreamSelector.hpp"
#include "antlr/TokenStreamRetryException.hpp"

#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE
namespace antlr {
#endif

/** A token stream MUX (multiplexor) knows about n token streams
 *  and can multiplex them onto the same channel for use by token
 *  stream consumer like a parser.  This is a way to have multiple
 *  lexers break up the same input stream for a single parser.
 *      Or, you can have multiple instances of the same lexer handle
 *  multiple input streams; this works great for includes.
 */

TokenStreamSelector::TokenStreamSelector()
: input(0)
{
}

TokenStreamSelector::~TokenStreamSelector()
{
}

void TokenStreamSelector::addInputStream(TokenStream* stream, const ANTLR_USE_NAMESPACE(std)string& key)
{
        inputStreamNames[key] = stream;
}

TokenStream* TokenStreamSelector::getCurrentStream() const
{
        return input;
}

TokenStream* TokenStreamSelector::getStream(const ANTLR_USE_NAMESPACE(std)string& sname) const
{
        inputStreamNames_coll::const_iterator i = inputStreamNames.find(sname);
        if (i == inputStreamNames.end()) {
                throw ANTLR_USE_NAMESPACE(std)string("TokenStream ")+sname+" not found";
        }
        return (*i).second;
}

RefToken TokenStreamSelector::nextToken()
{
        // keep looking for a token until you don't
        // get a retry exception
        for (;;) {
                try {
                        return input->nextToken();
                }
                catch (TokenStreamRetryException&) {
                        // just retry "forever"
                }
        }
}

TokenStream* TokenStreamSelector::pop()
{
        TokenStream* stream = streamStack.top();
        streamStack.pop();
        select(stream);
        return stream;
}

void TokenStreamSelector::push(TokenStream* stream)
{
        streamStack.push(input);
        select(stream);
}

void TokenStreamSelector::push(const ANTLR_USE_NAMESPACE(std)string& sname)
{
        streamStack.push(input);
        select(sname);
}

void TokenStreamSelector::retry()
{
        throw TokenStreamRetryException();
}

/** Set the stream without pushing old stream */
void TokenStreamSelector::select(TokenStream* stream)
{
        input = stream;
}

void TokenStreamSelector::select(const ANTLR_USE_NAMESPACE(std)string& sname)
{
        inputStreamNames_coll::const_iterator i = inputStreamNames.find(sname);
        if (i == inputStreamNames.end()) {
                throw ANTLR_USE_NAMESPACE(std)string("TokenStream ")+sname+" not found";
        }
        input = (*i).second;
}

#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE
}
#endif

Revision:	2469
Committed:	Fri Dec 2 15:38:03 2005 UTC (18 years, 7 months ago) by tim
File size:	2538 byte(s)
Log Message:	End of the Link --> List Return of the Oject-Oriented replace yacc/lex parser with antlr parser
#	Content
1	/* ANTLR Translator Generator
2	* Project led by Terence Parr at http://www.jGuru.com
3	* Software rights: http://www.antlr.org/license.html
4	*
5	* $Id: TokenStreamSelector.cpp,v 1.1 2005-12-02 15:38:02 tim Exp $
6	*/
7	#include "antlr/TokenStreamSelector.hpp"
8	#include "antlr/TokenStreamRetryException.hpp"
9
10	#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE
11	namespace antlr {
12	#endif
13
14	/** A token stream MUX (multiplexor) knows about n token streams
15	* and can multiplex them onto the same channel for use by token
16	* stream consumer like a parser. This is a way to have multiple
17	* lexers break up the same input stream for a single parser.
18	* Or, you can have multiple instances of the same lexer handle
19	* multiple input streams; this works great for includes.
20	*/
21
22	TokenStreamSelector::TokenStreamSelector()
23	: input(0)
24	{
25	}
26
27	TokenStreamSelector::~TokenStreamSelector()
28	{
29	}
30
31	void TokenStreamSelector::addInputStream(TokenStream* stream, const ANTLR_USE_NAMESPACE(std)string& key)
32	{
33	inputStreamNames[key] = stream;
34	}
35
36	TokenStream* TokenStreamSelector::getCurrentStream() const
37	{
38	return input;
39	}
40
41	TokenStream* TokenStreamSelector::getStream(const ANTLR_USE_NAMESPACE(std)string& sname) const
42	{
43	inputStreamNames_coll::const_iterator i = inputStreamNames.find(sname);
44	if (i == inputStreamNames.end()) {
45	throw ANTLR_USE_NAMESPACE(std)string("TokenStream ")+sname+" not found";
46	}
47	return (*i).second;
48	}
49
50	RefToken TokenStreamSelector::nextToken()
51	{
52	// keep looking for a token until you don't
53	// get a retry exception
54	for (;;) {
55	try {
56	return input->nextToken();
57	}
58	catch (TokenStreamRetryException&) {
59	// just retry "forever"
60	}
61	}
62	}
63
64	TokenStream* TokenStreamSelector::pop()
65	{
66	TokenStream* stream = streamStack.top();
67	streamStack.pop();
68	select(stream);
69	return stream;
70	}
71
72	void TokenStreamSelector::push(TokenStream* stream)
73	{
74	streamStack.push(input);
75	select(stream);
76	}
77
78	void TokenStreamSelector::push(const ANTLR_USE_NAMESPACE(std)string& sname)
79	{
80	streamStack.push(input);
81	select(sname);
82	}
83
84	void TokenStreamSelector::retry()
85	{
86	throw TokenStreamRetryException();
87	}
88
89	/** Set the stream without pushing old stream */
90	void TokenStreamSelector::select(TokenStream* stream)
91	{
92	input = stream;
93	}
94
95	void TokenStreamSelector::select(const ANTLR_USE_NAMESPACE(std)string& sname)
96	{
97	inputStreamNames_coll::const_iterator i = inputStreamNames.find(sname);
98	if (i == inputStreamNames.end()) {
99	throw ANTLR_USE_NAMESPACE(std)string("TokenStream ")+sname+" not found";
100	}
101	input = (*i).second;
102	}
103
104	#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE
105	}
106	#endif
107