CS606 assignment # 1

Suppose that you are working as a programmer in Microsoft. They

assigned you a task to draw a finite acceptor which can be useful

for lexical analyses of language L expressed as L = {w (a, b)* /

nb(w) mod 3 > 1.}. You are requested to analyze this language and

construct a deterministic finite acceptor of this language.

Question 2:

We can follow two approaches during the construction of lexical

analyzer. We can construct it as a separate module or it can

be a part of scanner. If scanner is the part of parse then in this

approach parser usually generates syntax tree of the source

program as defined by a grammar. The leaves of the tree are the

terminal symbols of the grammar. These terminal symbols or

tokens pass to the parser. But generally we choose to handle

analysis separately for the better modularity and portability, and

to allow make syntax analysis easier, so what are the reasons for

decoupling the scanner from parser?