Compilers

LR Parser

Question 1
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 2
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 3
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 4
Marks : +2 | -2
Pass Ratio : 100%
System program such as compiler are designed so that they are _________
Re-enterable
Non reusable
Serially usable
None of the mentioned
Explanation:
Re-enterable is the keyword for compiler being designed.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which of the following system program forgoes the production of object code to generate absolute machine code and load it into the physical main storage location from which it will be executed immediately upon completion of the assembly?
Two pass assembler
Load and go assembler
Macro processor
Linker
Explanation:
A load and go assembler generates absolute machine code and loads it to physical memory.
Question 6
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 7
Marks : +2 | -2
Pass Ratio : 100%
An LR-parser can detect a syntactic error as soon as __________
The parsing starts
It is possible to do so a left-to-right scan of the input
It is possible to do so a right-to-left scan of the input
Parsing ends
Explanation:
Error is found when it the input string is scanned.
Question 8
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 9
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 10
Marks : +2 | -2
Pass Ratio : 100%
What is the similarity between LR, LALR and SLR?
Use same algorithm, but different parsing table
Same parsing table, but different algorithm
Their Parsing tables and algorithm are similar but uses top down approach
Both Parsing tables and algorithm are different
Explanation:
The common grounds of these 3 parser is the algorithm but parsing table is different.