Test Book- Complier Design

Question

Consider the following issues

1. Simplifies the phases.
2. Compiler efficiency is improved.
3. Compiler works faster.
4. Does not require a stack.

Which is/are true in context of lexical analysis?

pls provide an explanation as well..

Comments

See here

https://gateoverflow.in/42577/lexical-analysis

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@kumar.dilip I was looking for the explanation...

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In that link why option D is not correct Lexical Analysis uses Finite Automata so it should be correct.Stack is required in Parseing phase as it uses CFL.

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@Soumya Tiwari @kumar.dilip The options for both the questions are a bit different.. The ans to this ques is that all the options are correct I am not getting that how?

Answer 1

1. True. By scanning the program and breaking it into tokens, it reduces the work of the parser.

2. True. Lexical Analyser scans through the symbol table in a sequential manner and replaces the identifiers present in the code with their location. This helps the rest of the phases to directly access the required identifier in a random manner and so saves time. Hence, efficiency is improved.

3. True. For the same reason as above, the rest of the phases are able to complete their function in less time. Though during lexical analyser phase, it surely takes the required time.

4. True. Lexical analyser is implemented through a DFA.

Comments

thanks..:) @Shaijal Tripathi