Compilers

LR Parser

Question 1
Marks : +2 | -2
Pass Ratio : 100%
If a state does not know whether it will make a shift operation or reduction for a terminal is called _________
Shift/reduce conflict
Reduce /shift conflict
Shift conflict
Reduce conflict
Explanation:
As the name suggests that the conflict is between shift and reduce hence it is called shift reduce conflict.
Question 2
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.
Question 3
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 4
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 5
Marks : +2 | -2
Pass Ratio : 100%
Which of these is also known as look-head LR parser?
SLR
LR
LLR
None of the mentioned
Explanation:
LLR is the look ahead parser.
Question 6
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 7
Marks : +2 | -2
Pass Ratio : 100%
The construction of the canonical collection of the sets of LR (1) items are similar to the construction of the canonical collection of the sets of LR (0) items. Which is an exception?
Closure and goto operations work a little bit different
Closure and goto operations work similarly
Closure and additive operations work a little bit different
Closure and associatively operations work a little bit different
Explanation:
Closure and goto do work differently in case of LR (0) and LR (1).
Question 8
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 9
Marks : +2 | -2
Pass Ratio : 100%
Advantage of incorporating the macro-processor into pass 1 is that _________
Many functions have to be implemented twice
Functions are combined not necessarily creating intermediate files as output from the macro-processor and input to the assembler
More flexibility is provided to the programmer in that he may use all the features of the assembler in conjunction with macros
All of the mentioned
Explanation:
A general-purpose macro processor or general purpose pre-processor is a macro designed primarily for string manipulation, macro definition.
Question 10
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.