Compilers

LR Parser

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is incorrect for the actions of A LR-Parser I) shift s ii) reduce A->ß iii) Accept iv) reject?
Only I)
I) and ii)
I), ii) and iii)
I), ii) , iii) and iv)
Explanation:
Only reject out of the following is a correct LR parser action.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
What is terminal table?
Contains all constants in the program
Is a permanent table of decision rules in the form of patterns for matching with the uniform symbol table to discover syntactic structure
Consist of a full or partial list of the token is as they appear in the program created by lexical analysis and used for syntax analysis and interpretation
Is a permanent table which lists all keywords and special symbols of the language in symbolic form
Explanation:
A permanent database that has entry for each terminal symbols such as arithmetic operators, keywords, punctuation characters such as ‘;’, ‘,’etc Fields: Name of the symbol.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
When ß (in the LR(1) item A -> ß.a,a) is not empty, the look-head _________
Will be affecting
Does not have any affect
Shift will take place
Reduction will take place
Explanation:
There is no terminal before the non terminal beta.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
When ß is empty (A -> ß.,a), the reduction by A-> a is done by _________
If next symbol is a terminal
Only If the next input symbol is a
Only If the next input symbol is A
Only if the next input symbol is a
Explanation:
The next token is considered in this case it’s a.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which of these is true about LR parsing?
Is most general non-backtracking shift-reduce parsing
It is still efficient
Is most general non-backtracking shift-reduce parsing & It is still efficient
None of the mentioned
Explanation:
LR parsers are a type of bottom-up parsers that efficiently handle deterministic context-free languages in guaranteed linear time.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
A series of statements explaining how the data is to be processed is called _________
Assembly
Machine
COBOL
Program
Explanation:
A program is a sequence of instructions, written to perform a task by computer. It requires programs to function, typically executing the program’s instructions in a central processor.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
A system program that setup an executable program in main memory ready for execution is?
Assembler
Linker
Loader
Load and go
Explanation:
A loader is the part of an operating system that is responsible for loading programs and libraries. It is one of the essential stages in the process of starting a program, as it places programs into memory and prepares them for execution.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
A loader is a program that _________
Program that places functions into memory and prepares them for execution
Program that automates the translation of assembly language into machine language
Program accepting another program written in a high level language and produces as object program
None of the mentioned
Explanation:
A loader is the part of an operating system that is responsible for loading programs and libraries. It is important in the process of placing the programs into memory and executing them.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Uniform symbol table _________
Has all constants in the program
Permanent table of rules in the form of patterns for matching with the uniform symbol table to discover syntactic structure
Consists of full or partial list of the tokens as they appear in the program created by Lexical analysis and used for syntax analysis and interpretation
A permanent table which has all key words and special symbols of the language in symbolic form
Explanation:
Each pass scans the program, the first pass generates the symbol table and the second pass generates the machine code.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is a phase of a compilation process?
Lexical Analysis
Code Generation
Lexical Analysis & Code Generation
None of the mentioned
Explanation:
Lexical analysis and code generation is a phase of compilation process.