Process of making Grammar Compiler Friendly

Duration: 6 min

This video lesson is available to enrolled students.

Return to /learn/MPPSC-ASSISTANT-PROFESSOR-COMPUTER-SCIENCE-PAPER-2/compiler-design/grammar-cfg/derivation-recursion/asset-process-of-making-grammar-compiler-friendly after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. Paper 1 | General Studies: State Wise GK
  3. Paper 1 | Information and Communication Technology: Role of Internet and Web Services, Security in Mobile and Wireless Computing
  4. Paper 1 | Current Affairs: GK- Current Affairs
  5. Paper 2 | Discrete Mathematical Structure: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Probability
  6. Paper 2 | Digital Computer Organization And Architecture: Number System, Number Representation, Sequential Circuits, Combinational Circuit, Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer
  7. Paper 2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  8. Paper 2 | Programming Languages & Object-Oriented Programming Concepts: Java, OOPS with C++, Java Fundamentals, Array, String, IO & References
  9. Paper 2 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  10. Paper 2 | Data Structure And Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Advanced Algorithms
  11. Paper 2 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS
  12. Paper 2 | Theory Of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory
  13. Paper 2 | Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
  14. Paper 2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization, Enhanced Data Models
  15. Paper 2 | Computer Network And Information Security: Introduction to CN, Data Communication, Application Layer, Hardware basics, Cyber Threats and Malware Attacks, Network Security, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP
  16. Paper 2 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  17. Paper 2 | Current Trends & Technologies: Emerging Tech Trends, Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Planning, Multi Agent Systems, Fuzzy Sets, Natural Language Processing, Artificial Neural Networks, Genetic Algorithms, Artificial Intelligence, Data Warehousing & Mining, Electronic Data Interchange and E-Commerce, Terms & Abbreviations
  18. Paper 2 | Full Length Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video lecture focuses on the process of making a Context-Free Grammar (CFG) compiler-friendly by eliminating left recursion. The instructor explains that left recursion can cause compilers to enter an infinite loop during the parsing process. To resolve this issue, the lecture demonstrates a standard algorithm to convert left-recursive productions into equivalent right-recursive productions. The session begins with a theoretical explanation of the problem, highlighting the risks of infinite loops. It then transitions into a practical example involving the specific grammar rule $A

ightarrow A\alpha / eta$. The instructor visually derives the new grammar rules and illustrates the equivalence through detailed parse tree diagrams, ensuring students understand how the structural changes preserve the generated language while making it suitable for top-down parsers.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a slide titled 'Process of making a CFG Compiler Friendly'. The text explicitly states that if a CFG contains left recursion, the compiler may go to an infinite loop. The instructor underlines the phrases 'left recursion' and 'infinite loop' in red to emphasize the core problem. He writes 'LR = RR' on the screen, signifying the goal of converting Left Recursion into Right Recursion. He draws a rough diagram to visualize the transformation process, setting the stage for the specific algorithm to be discussed. The slide also displays the logo 'Knowledge Gate Educator' and the instructor's name 'Sanchit Jain Sir'.

  2. 2:00 – 5:00 02:00-05:00

    The slide changes to a specific question: 'Consider the following Left recursive grammar and convert them into Corresponding Right recursive Grammar?'. The grammar shown is $A ightarrow A\alpha / eta$. The instructor draws parse trees for this left-recursive grammar, showing a left-heavy structure where $A$ expands to $A\alpha$ repeatedly, leading to a deep left branch. He then writes the solution: $A ightarrow eta A'$ and $A' ightarrow \alpha A' / \epsilon$. He draws the corresponding right-recursive parse trees, showing a right-heavy structure, to prove that both grammars generate the same language. The use of the epsilon symbol ($\epsilon$) is highlighted as the base case for the new non-terminal $A'$.

  3. 5:00 – 5:48 05:00-05:48

    The instructor concludes the example by circling the original grammar and the newly derived grammar rules in blue ink. He highlights the new non-terminal $A'$ which handles the repetition of $\alpha$. The visual comparison reinforces the concept that the left-recursive production $A ightarrow A\alpha$ is replaced by a right-recursive production involving $A'$. The lecture ends with a clear visual distinction between the problematic left-recursive form and the compiler-friendly right-recursive form, ensuring the student understands the final state of the conversion.

The lecture effectively bridges the gap between theoretical grammar problems and practical compiler design. By starting with the 'why' (infinite loops) and moving to the 'how' (conversion algorithm), the instructor provides a complete understanding of left recursion removal. The use of visual aids like parse trees and underlining key terms helps solidify the concept that $A ightarrow A\alpha / eta$ is equivalent to $A ightarrow eta A', A' ightarrow \alpha A' / \epsilon$. This transformation is crucial for making grammars suitable for top-down parsing techniques like Recursive Descent Parsing.

Loading lesson…