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Lex and YACC primer/HOWTO

PowerDNS BV (bert hubert <bert@powerdns.com>)

v0.8 $Date: 20 19:46:46 $

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This document tries to help you get started using Lex and YACC

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1. Introduction

• 1.1 What this document is NOT
• 1.2 Downloading stuff
• 1.3 License

2. What Lex & YACC can do for you

• 2.1 What each program does on its own

3. Lex

• 3.1 Regular expressions in matches
• 3.2 A more complicated example for a C like syntax
• 3.3 What we've seen

4. YACC

• 4.1 A simple thermostat controller
• 4.2 Expanding the thermostat to handle parameters
• 4.3 Parsing a configuration file

5. Making a Parser in C++

6. How do Lex and YACC work internally

• 6.1 Token values
• 6.2 Recursion: 'right is wrong'
• 6.3 Advanced yylval: %union

7. Debugging

• 7.1 The state machine
• 7.2 Conflicts: 'shift/reduce', 'reduce/reduce'

8. Further reading

9. Acknowledgements & Thanks

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