Designing LL(1) Parser Part-1

Duration: 8 min

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Inside: a video lesson and guided study material.

Module outline

  1. General Intelligence & Reasoning: Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Logical Sequence Of Words, Syllogisms, Venn Diagram, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Data Sufficiency, Puzzle Solving (Puzzles), Data Arrangement, Cubes & Dices, Calendar, Clock, Arithmetic, Number System, HCF LCM, Verbal Analogy (Word Based Analogy), Visual Recognition and Figure Completion, Paper Folding and Cutting, Transformation of Shapes, Clocks and Calendars, Direction Sense, Cubes and Dice, Patterns in Two-Dimensional Figures, Seating Arrangements, Analogy and Classification, Logical Deduction and Induction, Alphabet and Word Tests, Mathematical Operations, Series Completion, Simplification and Approximation, Coding and Decoding, Numerical Reasoning, Assembling and Grouping of Shapes, Three-Dimensional Patterns and Visualization, Vocabulary, Number System, Averages, Mixtures and Alligation, Simple and Compound Interest, Percentages, Algebra, Speed, Time and Distance, Seating and Arrangement Puzzles, Traverse Surveying, Order, Ranking and Sequence, Constraint Puzzles, Syllogisms and Venn Diagrams, Reading Comprehension, Critical Reasoning, Permutations and Combinations, Narrative Sequencing, Project Monitoring, Resources and Safety, Profit, Loss and Discount, Ratio and Proportion, Time and Work, Mensuration, Data Interpretation, Powers, Surds and Logarithms, Sequences and Series, Articles and Determiners, Sentence Completion, Data Sufficiency, Blood Relations, Simple Interest and Compound Interest, Mixture and Alligation, Sequence and Series (Series), Speed Time and Distance, Algebra, Profit and Loss, Powers and Exponents (Surds and Indices), Permutation and Combination
  2. General Awareness: Physics, Chemistry, Biology, History, Geography, Polity, Indian Economy, Environment, Static General Knowledge, GK- Current Affairs, Artificial Intelligence, MS Office Applications, Terms & Abbreviations, Keyboard Shortcuts, Evolution of Indian Banking (Banking & Financial Awareness), Emerging Tech Trends
  3. Engineering Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Linear Algebra, Calculus, Probability, Statistics, Signal Space and Optimum Detection, Probability, Statistics
  4. Digital Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep, Number Systems and Codes, Registers and Counters, Boolean Algebra and Logic Gates, Microprocessors and Microcontrollers, Logic Families and CMOS Logic, Microprocessors, Logic Gates and Boolean Algebra, Minimization of Boolean Functions, Timing, Hazards and Testing, Logic Families, Combinational Logic Design, Arithmetic Circuits, Waveform Generators and Timer Circuits, Semiconductor Memories and Programmable Logic Devices, Combinational Logic Circuits, Latches and Flip-Flops, Finite State Machines, Sequential Circuits and State Machines, Minimization of Boolean Functions, Arithmetic Circuits, Latches and Flip-Flops, Number Systems and Codes, Registers and Counters
  5. Computer Organisation & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer, Register Transfer and Microoperations, Semiconductor Memories and Programmable Logic, Processor Organization and Instructions, Memory Hierarchy and Input/Output, Registers and Counters
  6. Programming & Data Structures: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, HTML Basics, OOPS with C++, Java, Object Oriented Technology
  7. Databases: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization
  8. Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos
  9. 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
  10. 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
  11. Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Security, Windows OS, Distributed Systems, Unix OS, Linux OS
  12. Computer Networks: Introduction to CN, 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, Data Communication, Website, Browser & Services, Web Design & Development, Network Security, Cyber Threats and Malware Attacks, Cyber Safety and Security
  13. Full Length Mock Tests:
  14. Sectional Tests:
  15. Paper 2 - Full-length Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video is a detailed lecture on compiler design, specifically focusing on the construction of an LL(1) parsing table. The instructor, Sanchit Jain Sir, starts with a standard arithmetic expression grammar that exhibits left recursion: E -> E+T / T, T -> T*F / F, F -> (E) / id. He demonstrates the systematic process of eliminating left recursion to make the grammar suitable for top-down parsing. He rewrites the productions for E and T using new non-terminals (E' and T') and epsilon productions. Following the grammar transformation, he proceeds to calculate the First and Follow sets for each non-terminal. Finally, he constructs a parsing table, mapping the grammar productions to the appropriate cells based on the computed sets, effectively demonstrating how to build an LL(1) parser for the given grammar. This process is essential for understanding how compilers parse source code.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by displaying a context-free grammar on the top left of the screen: E -> E+T / T, T -> T*F / F, and F -> (E) / id. He underlines this grammar to emphasize it as the starting point. He explains that this grammar contains left recursion, which prevents it from being used for top-down parsing. To fix this, he starts rewriting the productions. He writes E -> T E' and E' -> + T E' / epsilon. He then applies the same transformation to the T productions, writing T -> F T' and T' -> * F T' / epsilon. Finally, he writes the F productions as F -> (E) / id. This section focuses on the algebraic manipulation of the grammar rules to eliminate left recursion, a prerequisite for LL(1) parsing. The instructor is identified as Sanchit Jain Sir from Knowledge Gate Educator. He uses red ink to write the new grammar, distinguishing it from the original orange text. The transformation involves introducing new non-terminals E' and T' to handle the recursive parts of the original grammar.

  2. 2:00 – 5:00 02:00-05:00

    With the grammar transformed, the instructor moves to calculating the First and Follow sets. He writes F(E) = { (, id } to denote the First set of E. He continues with F(E') = { +, epsilon }, F(T) = { (, id }, F(T') = { *, epsilon }, and F(F) = { (, id }. He then calculates the Follow sets, writing Follow(E) = { $, ) }, Follow(E') = { $, ) }, Follow(T) = { +, $, ) }, Follow(T') = { +, $, ) }, and Follow(F) = { *, +, $, ) }. These sets are written in a column on the right side of the board. The instructor explains that these sets determine which production to apply based on the current input symbol. He uses the notation F for First and Follow for Follow sets. He writes the Follow sets in blue ink, contrasting with the red First sets. The calculation of these sets is crucial for determining the entries in the parsing table.

  3. 5:00 – 8:28 05:00-08:28

    The instructor draws a large table with rows labeled E, E', T, T', F and columns labeled +, *, (, ), id, $. He begins filling the table cells. For E -> T E', he places the production in the columns corresponding to First(T), which are ( and id. For E' -> + T E', he places it in the + column. For E' -> epsilon, he places it in the columns corresponding to Follow(E'), which are $ and ). He repeats this for T and T', placing T -> F T' in ( and id, T' -> * F T' in *, and T' -> epsilon in +, $, ). Finally, he places F -> (E) in ( and F -> id in id. This demonstrates the construction of the LL(1) parsing table. The table is a grid where each cell represents a decision point for the parser. He uses red ink for the table lines and black ink for the productions. The final table allows the parser to determine the correct production to apply for any given input symbol.

The lecture provides a complete walkthrough of transforming a recursive grammar into an LL(1) form. It connects the theoretical steps of removing left recursion with the practical application of building a parsing table. By calculating First and Follow sets and then populating the table, the instructor shows the full pipeline from grammar definition to parser construction, a fundamental concept in compiler design. This process ensures that the parser can handle the grammar without ambiguity.

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