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| == Basic Concepts ==
| | #REDIRECT [[ist:The Flex Lexical Analyzer]] |
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| * Definitions
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| * Rules, actions
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| * Code
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| * States and sub-automata
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| == Structure of a Flex Specification ==
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| == How to Debug a Flex Specification ==
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| There are various flags and variables to activate the debug functionality in Flex (there is no need to insert useless code such as printfs or similar).
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| The debug option will activate code for debugging as will the call to the <tt>set_debug</tt> method (see the scanner header file in Compact for an example).
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| In the CompactScanner.l file:
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| %option debug
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| In the CompactScanner.h file (in the constructor):
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| set_debug(1);
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| Also, the YYDEBUG environment variable will activate the debug messages '''both''' in Flex and YACC (allowing debug of token recognition by the scanner and use by the parser).
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| == Examples ==
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| * [[Extracting HREF attributes from HTML files]]
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| [[category:Compilers]] | |
| [[category:Teaching]]
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