Designing LR(O) Parser Part-5

Duration: 4 min

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Module outline

  1. Discrete Mathematics: Permutation, Combination and Probability / क्रमचय, संचय एवं प्रायिकता, Set Theory, Relations, Functions, Propositional and Predicate Logic, Graph Theory, Group Theory
  2. Digital Logic: Digital Systems & Boolean Basics, Boolean Expression, Boolean Minimization, Logic Gates & Hardware, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep
  3. Computer Organization and Architecture: Basics of COA, Programming the Basic Computer, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design, Pipelining, Multiprocessors
  4. Programming: Language Design, C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, OOPS with C++
  5. Data Structures: Introduction to DS, Array, Linked List, Stack, Queue, Tree, Graphs, Hashing
  6. Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  7. Theory of Computation: Grammar, Regular Language Properties, Moore & Mealy Machines, Turing Machines
  8. 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, Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Pushdown Automata & CFG, Complexity Theory
  9. Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS, Linux OS, Security
  10. Database Management Systems: 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, ORDBMS, NoSQL
  11. Computer Networks: 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
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video lecture provides a detailed explanation of "Conflicts in LR(0) parser," a fundamental topic in compiler design. The instructor categorizes conflicts into two distinct types: "SR Conflicts (Shift Reduce)" and "RR Conflicts (Reduce Reduce)." He explains the specific conditions required for each conflict to occur within the states of a Deterministic Finite Automaton (DFA). For SR conflicts, he notes that they arise when a state contains both final and non-final items. For RR conflicts, he explains they happen when a state contains more than one final item. The lecture concludes by defining an "LR(0) Grammar" as an unambiguous grammar where the parse table is free from these multiple entries, ensuring deterministic parsing.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor starts by introducing the slide titled "Conflicts in LR(0) parser." He highlights the bullet points for "SR Conflicts (Shift Reduce)" and "RR Conflicts (Reduce Reduce)." He focuses on the SR conflict section, reading the text: "If the state of DFA contains both final & non-final items, then it is S-R conflicts." He points to the example rules A -> alpha.x beta (labeled as shift) and B -> delta . (labeled as reduced). To visualize this, he circles the production A -> alpha.x beta and the production B -> delta . with a red pen. He then draws a horizontal line with vertical dividers to represent the parse table or state structure, indicating where the shift and reduce actions would clash. He emphasizes that the presence of x (a terminal) necessitates a shift, while the dot at the end of B necessitates a reduction.

  2. 2:00 – 4:05 02:00-04:05

    The instructor transitions to the second type of conflict, "R-R Conflict." He reads the definition: "If the same state contains more than one final item, then it is R-R Conflict." He points to the example rules A -> alpha . and B -> alpha .. Although the text next to A says "(x is terminal, shift)", the instructor circles both A -> alpha . and B -> alpha . to show they are both final items causing a conflict. He then moves to the final bullet point defining "LR(0) Grammar." He reads the text: "An unambiguous grammar LR(0) parse table is free from multiple entries, i.e. free both SR & RR conflicts, is LR(0) grammar." He circles the title "Conflicts in LR(0) parser" again to summarize the entire topic covered in the session.

The lecture progresses logically from identifying specific conflict types to defining the grammar that avoids them. By visually circling the conflicting production rules and drawing diagrams, the instructor clarifies the abstract concepts of shift-reduce and reduce-reduce conflicts. The final definition establishes that a grammar is LR(0) only if its parse table contains no such ambiguities.

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