Question

5. Describe informally the kind of pattern that matches the following extended regular expression: [b-d]a?e+ and rewrite it using only the basic (not extended) features of formal regular expressions. [For example, character classes [.1 positive closures +, and optionals? are not basic features, and should be expressed using only the basic taxonomy instead]. [4 marks 6. Explain the assertion that " there is more to taking Compiler Construction course than solely at writing a typical compiler" aiming [3 marks

Answer 1

5. The unextended or formal regular expression corresponds to the given extended regular expression ([b-d]a? e*) is:

= (b|c|d) (a|€) (e|ee*), where € is representing empty string.

This regular expression contains string that start with either b, C, d and end with either single e Or more that one e. Either single a or null will be present in between of 1st and last character. Total length of all the strings from this RE are of either 2 or 3.

6. Compiler construction course is more important than writing a typical compiler, because during course study we will get know different type of compiler construction, that we won't be able to get in writing a compiler.