CxxScanner Class Reference
This wraps the scanner that flex produces.
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#include <cxxScanner.h>
List of all members.
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Public Types |
| enum | { HSIZE = 128,
HMASK = 127
} |
Public Member Functions |
| | CxxScanner (const char *fileName) |
| | ~CxxScanner () |
| Token | read (const char *errStr=0) |
| void | pushBack (Token &t) |
| Token | prevToken (int i) |
Static Public Member Functions |
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static const char * | filename () |
| | current filename.
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static int | lineNo () |
| | current line number (1 based).
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static int | column (int icol) |
| | current column (1 based);
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Private Attributes |
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int | m_current |
| | Current indx for m_tokens.
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std::vector< Token > | m_tokens |
| | Current tokens.
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int | m_stackCnt |
| | Push back stack counter.
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int | m_stdin |
| | True when using standard in as input.
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Obstack | m_s |
Static Private Attributes |
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static char * | mp_fileName |
| | Current file name.
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Detailed Description
This wraps the scanner that flex produces.
- Description
- This class encapsulates the data that the scanner produces. It has the following features.
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You can push back one token without going to the Flex push back
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It keeps track of the input file line numbers.
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It remembers the previous 128 non-white space tokens
- Design Considerations
- This class is designed for speed. The read function is written carefully to take advantage of Return Value Optimization. (RVO). The recording of the previous tokens is implemented as a circular buffer for speed. The input line numbers are counted so that if there is a problem then the error can be reported directly to the input line that fails.
Constructor & Destructor Documentation
| CxxScanner::CxxScanner |
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const char * |
fileName |
) |
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This ctor opens the input file (or sets yyin to stdin) and sets up the circular buffer and initializes the line counter. |
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This closes the input file and delete mp_fileName. |
Member Function Documentation
| Token CxxScanner::prevToken |
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int |
i |
) |
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Extract the i'th previous non space token. |
| void CxxScanner::pushBack |
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Token & |
t |
) |
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Save away the current token and move the circular buffer back one if it is not a space. |
| Token CxxScanner::read |
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const char * |
errStr = 0 |
) |
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- Description
- If there is something on the stack (1 deep) use it. Otherwise ask yylex to get the next token. Then for any non white space token add it to the circular buffer.
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The documentation for this class was generated from the following file: