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#ifndef INC_TokenStreamSelector_hpp__ |
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#define INC_TokenStreamSelector_hpp__ |
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|
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/* ANTLR Translator Generator |
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* Project led by Terence Parr at http://www.jGuru.com |
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* Software rights: http://www.antlr.org/license.html |
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* |
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* $Id$ |
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*/ |
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|
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#include <antlr/config.hpp> |
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#include <antlr/TokenStream.hpp> |
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#include <map> |
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#include <stack> |
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|
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#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE |
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namespace antlr { |
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#endif |
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|
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/** A token stream MUX (multiplexor) knows about n token streams |
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* and can multiplex them onto the same channel for use by token |
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* stream consumer like a parser. This is a way to have multiple |
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* lexers break up the same input stream for a single parser. |
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* Or, you can have multiple instances of the same lexer handle |
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* multiple input streams; this works great for includes. |
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*/ |
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class ANTLR_API TokenStreamSelector : public TokenStream { |
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protected: |
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/** The set of inputs to the MUX */ |
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#ifdef OS_NO_ALLOCATOR |
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typedef ANTLR_USE_NAMESPACE(std)less<ANTLR_USE_NAMESPACE(std)string> lessp; |
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typedef ANTLR_USE_NAMESPACE(std)map<ANTLR_USE_NAMESPACE(std)string,TokenStream*,lessp> inputStreamNames_coll; |
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#else |
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typedef ANTLR_USE_NAMESPACE(std)map<ANTLR_USE_NAMESPACE(std)string,TokenStream*> inputStreamNames_coll; |
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#endif |
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inputStreamNames_coll inputStreamNames; |
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|
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/** The currently-selected token stream input */ |
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TokenStream* input; |
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|
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/** Used to track stack of input streams */ |
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#ifdef OS_NO_ALLOCATOR |
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typedef ANTLR_USE_NAMESPACE(std)stack<TokenStream*, ANTLR_USE_NAMESPACE(std)deque<TokenStream*> > streamStack_coll; |
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#else |
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typedef ANTLR_USE_NAMESPACE(std)stack<TokenStream*> streamStack_coll; |
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#endif |
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streamStack_coll streamStack; |
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|
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public: |
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TokenStreamSelector(); |
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~TokenStreamSelector(); |
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|
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void addInputStream(TokenStream* stream, const ANTLR_USE_NAMESPACE(std)string& key); |
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|
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/// Return the stream from which tokens are being pulled at the moment. |
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TokenStream* getCurrentStream() const; |
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|
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TokenStream* getStream(const ANTLR_USE_NAMESPACE(std)string& sname) const; |
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|
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RefToken nextToken(); |
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|
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TokenStream* pop(); |
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|
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void push(TokenStream* stream); |
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|
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void push(const ANTLR_USE_NAMESPACE(std)string& sname); |
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|
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/** Abort recognition of current Token and try again. |
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* A stream can push a new stream (for include files |
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* for example, and then retry(), which will cause |
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* the current stream to abort back to this.nextToken(). |
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* this.nextToken() then asks for a token from the |
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* current stream, which is the new "substream." |
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*/ |
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void retry(); |
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|
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/** Set the stream without pushing old stream */ |
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void select(TokenStream* stream); |
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|
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void select(const ANTLR_USE_NAMESPACE(std)string& sname); |
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}; |
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|
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#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE |
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} |
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#endif |
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|
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#endif //INC_TokenStreamSelector_hpp__ |