OSX/libsecurity_codesigning/antlr2/src/TokenStreamSelector.cpp

   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: //depot/code/org.antlr/release/antlr-2.7.7/lib/cpp/src/TokenStreamSelector.cpp#2 $
   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