/* ANTLRTokenBuffer.h
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*
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* SOFTWARE RIGHTS
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*
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* We reserve no LEGAL rights to the Purdue Compiler Construction Tool
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* Set (PCCTS) -- PCCTS is in the public domain. An individual or
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* company may do whatever they wish with source code distributed with
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* PCCTS or the code generated by PCCTS, including the incorporation of
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* PCCTS, or its output, into commerical software.
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*
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* We encourage users to develop software with PCCTS. However, we do ask
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* that credit is given to us for developing PCCTS. By "credit",
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* we mean that if you incorporate our source code into one of your
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* programs (commercial product, research project, or otherwise) that you
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* acknowledge this fact somewhere in the documentation, research report,
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* etc... If you like PCCTS and have developed a nice tool with the
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* output, please mention that you developed it using PCCTS. In
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* addition, we ask that this header remain intact in our source code.
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* As long as these guidelines are kept, we expect to continue enhancing
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* this system and expect to make other tools available as they are
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* completed.
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*
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* ANTLR 1.33
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* Terence Parr
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* Parr Research Corporation
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* with Purdue University and AHPCRC, University of Minnesota
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* 1989-2000
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*/
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#ifndef ATOKENBUFFER_H_GATE
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#define ATOKENBUFFER_H_GATE
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#include "pcctscfg.h"
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#include "pccts_stdlib.h"
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PCCTS_NAMESPACE_STD
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#include ATOKEN_H
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#include ATOKENSTREAM_H
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/*
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* The parser is "attached" to an ANTLRTokenBuffer via interface
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* functions: getToken() and bufferedToken(). The object that actually
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* consumes characters and constructs tokens is connected to the
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* ANTLRTokenBuffer via interface function ANTLRTokenStream::getToken();
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* where ANTLRTokenStream is really just a behavior (class with no data).
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* C++ does not have this abstraction and hence we simply have come up
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* with a fancy name for "void *". See the note in ANTLRTokenStream.h on
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* the "behavior" of ANTLRTokenStream.
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*/
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class ANTLRParser; // MR1
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class DllExportPCCTS ANTLRTokenBuffer {
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protected:
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ANTLRTokenStream *input; // where do I get tokens
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int buffer_size;
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int chunk_size;
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int num_markers;
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int k; // Need at least this many tokens in buffer
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_ANTLRTokenPtr *buffer; // buffer used for arbitrary lookahead
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_ANTLRTokenPtr *tp; // pts into buffer; current token ptr
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_ANTLRTokenPtr *last; // pts to last valid token in buffer
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_ANTLRTokenPtr *next; // place to put token from getANTLRToken()
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_ANTLRTokenPtr *end_of_buffer;
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/* when you try to write a token past this and there are no markers
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set, then move k-1 tokens back to the beginning of the buffer.
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We want to stay away from the end of the buffer because we have
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to extend it if a marker is set and we reach the end (we cannot
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move tokens to the beginning of the buffer in this case).
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*/
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_ANTLRTokenPtr *threshold;
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unsigned char _deleteTokens;
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// This function is filled in by the subclass; it initiates fetch of input
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virtual _ANTLRTokenPtr getANTLRToken() { return input->getToken(); }
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void makeRoom();
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void extendBuffer();
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public:
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ANTLRTokenBuffer(ANTLRTokenStream *in, int k=1, int chksz=50);
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virtual ~ANTLRTokenBuffer();
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virtual _ANTLRTokenPtr getToken();
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virtual void rewind(int pos);
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virtual int mark();
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virtual _ANTLRTokenPtr bufferedToken(int i);
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void noGarbageCollectTokens() { _deleteTokens=0; }
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void garbageCollectTokens() { _deleteTokens=1; }
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virtual int bufferSize() { return buffer_size; }
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virtual int minTokens() { return k; }
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virtual void setMinTokens(int k_new) { k = k_new; }
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virtual void panic(const char *msg); /* MR20 const */
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virtual int printMessage(FILE* pFile, const char* pFormat, ...); // MR23
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protected: // MR1
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ANTLRParser *parser; // MR1
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public: // MR1
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ANTLRParser *setParser(ANTLRParser *p); // MR1
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ANTLRParser *getParser(); // MR1
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ANTLRTokenStream *getLexer() const { // MR12
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return input;} // MR12
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};
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#endif
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