Designing LR(O) Parser Part-4

Duration: 7 min

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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.

This lecture introduces the architecture of a Bottom-Up LR Parser, detailing its three main components: input buffer, parse stack, and parse table. It progresses to explain the construction of the LR parser table, covering augmented grammars, LR(0) items, canonical collections, and the closure and GOTO functions used to generate the parser states. The instructor uses diagrams and text slides to illustrate the flow of data and the logic behind parsing decisions, providing a comprehensive overview of the theoretical underpinnings of LR parsing.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video begins with a slide titled 'Model of an LR Parser', listing three components: i/p buffer, Parse stack, and Parse table. The instructor highlights the input buffer cells containing symbols $a_1, a_2, \dots, a_n, \$$ and the stack containing states $S_m, X_m, \dots, S_0$. He explains the central 'LR Parsing Program (driver)' box, which uses the parse table to decide operations. The table is split into 'action' and 'goto' parts, governing 'shift', 'reduce', 'accept', and 'error' operations based on the current state and input symbol. Arrows indicate the flow of information between the input, stack, and the driver program. The 'action' table lists 'shift', 'reduce', 'accept', 'error', while the 'goto' table is labeled 'DFA'.

  2. 2:00 – 5:00 02:00-05:00

    The lecture transitions to text slides defining these components. The input buffer is described as cells holding one input symbol each. The stack holds grammar symbols pushed or popped via shift and reduce operations. The parse table is constructed using terminals, non-terminals, and LR(0) items, consisting of an 'Action' part for terminals and a 'Goto' part for non-terminals. A table structure is shown with columns for terminals ($t_1, t_2$) and non-terminals. The instructor then presents a grammar $A ightarrow aA / b$ and draws its state diagram with states $I_0$ through $I_4$, along with the corresponding parse table. He concludes this section by defining LR(K), where L stands for left-to-right scanning, R for reverse of right-most derivation, and K for the Look-Ahead symbol. The slide 'Operation in shift/reduced passer' lists 'shift', 'reduced', 'accept', 'error'. The table shows 'Action' for terminals and 'Goto' for non-terminals.

  3. 5:00 – 6:47 05:00-06:47

    The final section details the 'Procedure for the construction of LR Parser table'. Step 1 is obtaining the augmented grammar by adding a new start symbol $S' ightarrow S$. Step 2 involves creating the canonical collection of LR items. Step 3 is drawing the DFA and preparing the table. The instructor defines an LR(0) item as a production with a dot anywhere on the RHS, such as $A ightarrow .abc$. He explains the 'Closure' function: if $A ightarrow \alpha.eta B$ is in the closure, add $B ightarrow .\delta$ for all productions $B ightarrow \delta$. He also explains the 'GOTO' function, where $GOTO(I, X)$ moves the dot past symbol X to form a new set of items, which is then closed. The slide 'Function used to generate LR(0) item's' shows the specific formulas for these operations, including $GOTO(A ightarrow \alpha.Xeta, X) = A ightarrow \alpha X . eta$. The instructor draws diagrams to illustrate the closure process, showing how new items are added to the set. He emphasizes that the GOTO function is used to transition between states in the DFA based on the input symbol.

The lecture systematically builds the theoretical foundation for LR parsing, moving from the high-level model of the parser to the specific algorithms required to construct the parsing table, emphasizing the roles of augmented grammars and item sets. It connects the abstract definitions of LR items to the concrete steps of building the parser table.

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