University:
California State University, Northridge
Course:
COMP 333 | Concepts of Programming Languages
Academic year:

2023
Views:

303

Pages:

4
Author:

S Kim

NYI NYI MOE HTET COMP 333 ASSIGNMENT 4 Review Questions: 1. Explain the three reasons why lexical analysis is separate from syntax analysis. Simplification of Parser Complexity: The decision to separate lexical analysis from syntax analysis is driven by the need to simplify the parser's complexity. By having the parser deal with a sequence of tokens rather than raw text, the overall parsing process becomes more streamlined and manageable. Optimized Performance: The separation allows syntax analysis to independently focus on the more complex task of parsing without being influenced by character-level considerations. Simultaneously, lexical analysis can transform text into tokens, optimizing the overall performance of the parsing process. Improved Error Handling Efficiency: The segregation of lexical and syntax analysis contributes to faster error detection and diagnosis. This separation enables each phase to deliver more precise error messages, enhancing the efficiency of error handling in the overall parsing process. 2. What Is a State Transition Diagram? A State Transition Diagram is a visual tool representing Finite State Machines, displaying transitions between states triggered by events and conditions. The transitions, depicted as arrows connecting circles or rounded rectangles, model system behavior by illustrating all possible states and their dynamic changes. 3. Why are character classes used, rather than individual characters, for the letter and digit transitions of a state diagram for a lexical analyzer? Character classes are used in lexical analyzer state diagrams for transitions involving letters and digits. This simplifies the representation by grouping similar characters, such as all letters or digits, together. It eliminates the need to transition on individual characters separately, making the diagram more concise. 4. Describe the differences between top-down and bottom-up parsers. Top-down parsers match the input against a grammar's productions, starting from the root and progressing to the leaves. On the other hand, bottom-up parsers match input tokens with the grammar's productions, beginning from the leaves and moving upwards. Problem Set: 1. Given the following grammar and right sentential form,draw a parse tree and show the phrases and simple phrases, as well as the handle. S→aAb | bBAA→ab | aABB→aB | b 2. Given the following grammar and right sentential form,draw parse tree and show the phrases and simple phrases, as well as the handle. S→AbB | bAcA→Ab | aBBB→Ac | cBb | c