Which operations are executed during the parsing process to compute attributes or perform actions based on the grammar?

Which operations are executed during the parsing process to compute attributes or perform actions based on the grammar?

• A. Semantic Actions
• B. Syntax Checks
• C. Type Inference
• D. Lexical Analysis

Answer: (A)

Semantic actions are code blocks attached to grammar productions and executed during parsing as rules are reduced. They enable computing attributes such as types or values and performing actions like building an abstract syntax tree, updating symbol tables, or generating intermediate code. Lexical analysis tokenizes the input before parsing, so it doesn’t run during parsing. Type inference happens later in semantic analysis after the syntax has been recognized. Syntax checks describe the parser’s job of ensuring the input fits the grammar, not the per-rule actions that produce runtime attributes or side effects.

Semantic actions are code blocks attached to grammar productions and executed during parsing as rules are reduced. They enable computing attributes such as types or values and performing actions like building an abstract syntax tree, updating symbol tables, or generating intermediate code. Lexical analysis tokenizes the input before parsing, so it doesn’t run during parsing. Type inference happens later in semantic analysis after the syntax has been recognized. Syntax checks describe the parser’s job of ensuring the input fits the grammar, not the per-rule actions that produce runtime attributes or side effects.