| 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 |
* $Id$ |
| 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 |
|
