Designing LL(1) Parser Part-2

Duration: 6 min

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Module outline

  1. Quantitative Aptitude: Ratio and Proportion (Ratios), Data Interpretation, Mixture and Alligation, Permutation and Combination, Number System, Sequence and Series (Series), Speed Time and Distance, Speed Mathematics and Basic Mathematics, Algebra, Percentage, Profit and Loss, Simple Interest and Compound Interest, Powers and Exponents (Surds and Indices), Time and Work, Mensuration and Geometry, Partnership
  2. Reasoning Ability: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Seating Arrangements, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Directions (Direction Test), Ranking, Order and Sequence, Syllogisms, Blood Relations, Puzzle Solving (Puzzles), Inequality, Machine Input-Output
  3. English Language: Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Sentence Construction, Pronoun, Preposition, Conjunction, Adverb, Verb, Modals, Articles, Determiner, Interjection
  4. General Awareness: Evolution of Indian Banking (Banking & Financial Awareness), GK- Current Affairs, Static General Knowledge, Indian Economy
  5. C Concepts + MCQs (IT Specialist): C Programming by Yash Sir, C Language Core
  6. Java (IT Specialist): Java
  7. Python (IT Specialist): Python for Placements by Yash Sir, Python Basics
  8. OOPs (IT Specialist): Object Oriented Programming (OOPS)
  9. DBMS (IT Specialist): Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  10. SQL (IT Specialist): SQL
  11. Software Engineering (IT Specialist): Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  12. Data Structure (IT Specialist): Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  13. Operating System (IT Specialist): Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  14. Compiler Design (IT Specialist): 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
  15. Computer Architecture (IT Specialist): Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Multiprocessors, Programming the Basic Computer
  16. Data Communication & Networking (IT Specialist): Introduction to CN, Data Communication, 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, Application Layer, Hardware basics, Network Security
  17. Descriptive Test (Main Exam): English Writing Ability
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video lecture provides a comprehensive guide to constructing a predictive parsing table for a context-free grammar used in compiler design. The instructor starts by presenting a standard arithmetic expression grammar involving addition, multiplication, parentheses, and identifiers. He demonstrates the critical step of eliminating left recursion to transform the grammar into a form suitable for LL(1) parsing. Following this transformation, he systematically calculates the First and Follow sets for all non-terminals, including E, E', T, T', and F. The core of the lecture involves filling out a parsing table based on these sets, placing production rules into specific cells determined by the terminal symbols. The instructor verifies that the resulting table is conflict-free, confirming the grammar's LL(1) property, which is essential for deterministic top-down parsing.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by writing the original grammar rules on the left side of the board: E -> E + T / T, T -> T * F / F, and F -> (E) / id. He explains the need to remove left recursion to make the grammar suitable for predictive parsing. He then writes the transformed grammar: E -> T E', E' -> + T E' / epsilon, T -> F T', T' -> * F T' / epsilon, and F -> (E) / id. Below this, he systematically calculates the First and Follow sets for each non-terminal. Visible sets include First(E) = {(, id}, Follow(E) = {$, )}, First(E') = {+, epsilon}, and Follow(E') = {$, )}. He also lists First(T) = {(, id}, Follow(T) = {+, *, ), $}, First(T') = {*, epsilon}, Follow(T') = {+, *, ), $}, First(F) = {(, id}, and Follow(F) = {+, *, ), $}. He then begins the process of constructing the parsing table by identifying the terminals +, *, (, ), id, and $. He places the production E -> T E' into the cells corresponding to the First set of E, which are ( and id.

  2. 2:00 – 5:00 02:00-05:00

    The instructor proceeds to fill the remaining cells of the parsing table. For the non-terminal E', he places the production E' -> + T E' in the column for the terminal +. He then places the epsilon production E' -> epsilon in the columns corresponding to the Follow set of E', which are ) and $. Moving to the row for T, he places T -> F T' in the ( and id columns, matching the First set of T. For the non-terminal T', he places T' -> * F T' in the * column. He then fills the epsilon production T' -> epsilon into the columns for +, *, ), and $, which correspond to the Follow set of T'. Finally, for the row F, he places F -> (E) in the ( column and F -> id in the id column.

  3. 5:00 – 6:18 05:00-06:18

    The instructor completes the final entries in the parsing table, ensuring that all epsilon productions are correctly mapped to the Follow sets of their respective non-terminals. He reviews the entire table, pointing out that every cell contains at most one production rule. He states that the absence of conflicts in the table confirms that the grammar is LL(1). He explains that this property allows the parser to make deterministic decisions without backtracking. He concludes the lecture by summarizing the importance of the predictive parsing table in compiler construction.

This lecture connects grammar transformation with parsing table construction. By removing left recursion and calculating First and Follow sets, the instructor shows how to build a predictive parsing table. The final conflict-free table demonstrates that the grammar is LL(1), allowing for efficient parsing without backtracking. This process is fundamental for understanding how compilers analyze and translate source code.

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