Computer-Networks
February 12, 2024Compiler-Design
February 12, 2024Compiler-Design
| Question 2 |
Consider the following grammar (that admits a series of declarations, followed by expressions) and the associated syntax directed translation (SDT) actions, given as pseudo-code:
P ⟶ D* E*
D ⟶ int ID {record that ID.lexeme is of type int}
D ⟶ bool ID {record that ID.lexeme is of type bool}
E ⟶ E1 + E2 {check that E1.type = E2.type = int; set E.type := int}
E ⟶ !E1 {check that E1.type = bool; set E.type := bool}
E ⟶ ID {set E.type := int}
With respect to the above grammar, which one of the following choices is correct?
P ⟶ D* E*
D ⟶ int ID {record that ID.lexeme is of type int}
D ⟶ bool ID {record that ID.lexeme is of type bool}
E ⟶ E1 + E2 {check that E1.type = E2.type = int; set E.type := int}
E ⟶ !E1 {check that E1.type = bool; set E.type := bool}
E ⟶ ID {set E.type := int}
With respect to the above grammar, which one of the following choices is correct?
| The actions can be used to type-check syntactically correct integer variable declarations and integer expressions. | |
| The actions will lead to an infinite loop. | |
| The actions can be used to type-check syntactically correct boolean variable declarations and boolean expressions. | |
| The actions can be used to correctly type-check any syntactically correct program. |
Question 2 Explanation:
This SDT will never lead to infinite loop so option 2 is false. This SDT is type checking for bool as well as integer variables, hence this SDT can be used to correctly type-check any syntactically correct program involving boolean and integer variables.
Correct Answer: A
Question 2 Explanation:
This SDT will never lead to infinite loop so option 2 is false. This SDT is type checking for bool as well as integer variables, hence this SDT can be used to correctly type-check any syntactically correct program involving boolean and integer variables.
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