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Ch02 simple syntax semantic_actions_2019
- 1. 1 Ms. Bushra Abdullah Al-Anesi Compiler Construction Alfred V. Aho, , "Compilers", Addison Wesley Publishing Company; 2 edition (2007).
- 2. A Simple Syntax-Directed Translator Chapter 2 1/23/2019 2
- 3. Translation Schemes Cont. 1/23/2019 3 ❑ Syntax-directed definition for a BNF grammar ❑A syntax-directed translation scheme is a notation for specifying a translation by attaching program fragments to productions in a grammar. ❑A translation scheme is like a syntax-directed definition, except that the order of evaluation of the semantic rules is explicitly specified. ❑ Program fragments embedded within production bodies are called semantic actions. ❑ The position at which an action is to be executed is shown by enclosing it between curly braces and writing it within the production body, as in rest -> + term {print('+') } restl Embedded semantic action
- 4. New BNF Productions and Parse Trees Using Semantic Actions 1/23/2019 4 ❑ Actions are added in the productions ❑ When drawing a parse tree • Indicate an action by constructing an extra child for it, connected by a dashed line to the node that corresponds to the head of the production
- 5. 1/23/2019 5 ❑ Actions embedded in the production bodies translate such expressions into postfix notation, provided we perform a left-to- right depth-first traversal of the tree and execute each print statement when we visit its leaf. New BNF Productions and Parse Trees Using Semantic Actions
- 6. 1/23/2019 6 ❑ Actions embedded in the production bodies translate such expressions into postfix notation, provided we perform a left-to- right depth-first traversal of the tree and execute each print statement when we visit its leaf. Actions Translating 9-5+2 into 95-2+ New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 7. 1/23/2019 7 New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 8. 1/23/2019 7 New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 9. 1/23/2019 7 9 New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 10. 1/23/2019 7 9 New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 11. 1/23/2019 7 9 5 New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 12. 1/23/2019 7 9 5 New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 13. 1/23/2019 7 9 5 - New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 14. 1/23/2019 7 9 5 - New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 15. 1/23/2019 7 9 5 - 2 New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 16. 1/23/2019 7 9 5 - 2 New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 17. 1/23/2019 7 9 5 - 2 + New BNF Productions and Parse Trees Using Semantic Actions: Actions Translating 9-5+2 into 95-2+
- 18. 1/23/2019 8 Resource Alfred V. Aho, , "Compilers", Addison Wesley Publishing Company; 2 edition (2007).