Syntax directed translation associates semantic rules and actions with a context-free grammar to evaluate expressions during parsing. It allows parsers to perform semantic checks and code generation by storing values in symbol tables and generating intermediate code as parsing occurs through techniques like top-down left-to-right parsing. An example is given of using these methods to evaluate the expression 2 + 3 * 4 during parsing.

1. Syntax Directed Translation
• Typically for grammars we are given some parsers
• In practice of compiler design we associate some informal notations
i.e.

2. Why use semantic rules?
• Syntax analysis
• Code generation
• Storing some values in symbol table
• Intermediate code generation
• Expression evaluation
• Can be done in parallel
At the time when parsing is being done

3. • Parsers are cable of doing more when we give along with grammars
some other semantic actions
• Lets see an example to evaluate an expression

4. Lets Evaluate 2 + 3 * 4
Now parse it
Top-Down Left-To-Right

6. Translation of assignment