LL1 Parsing Table Lecture Notes

Introduction

• Topic: LL1 Parsing Table
• Focus: Construction of the LL1 Parsing Table

Session Outcomes

• Understanding the construction of LL1 parsing table.
• Review of previously covered topics: top-down parsers, LL1 parsers, FIRST and FOLLOW sets.

Importance of LL1 Parsing Table

• LL1 parsers need a parsing table and a stack to generate a parse tree.
• The table is constructed using FIRST and FOLLOW sets for non-terminals.

Grammar Review

• Reminder of previously studied grammar and FIRST and FOLLOW sets.
• Non-terminals and terminal symbols involved:
  • Non-terminals: E, E', T, T', F
  • Terminal symbols: id, (, ), *, +, $

Structure of LL1 Parsing Table

• Rows: non-terminals
• Columns: terminal symbols

Construction Process

Non-terminal E

• Production rule: E -> T E'
• Place in columns for id and (.

Non-terminal E'

• Production rules: E' -> + T E' | ε
• Place in column for + and ε in columns for $ and ).

Non-terminal T

• Production rule: T -> F
• Place in columns for id and (.

Non-terminal T'

• Production rules: T' -> * F T' | ε
• Place in column for * and ε in columns for +, $, and ).

Non-terminal F

• Production rules: F -> id | ( E )
• Place in columns for id and (.

Rules for Construction

1. Epsilon productions are placed under FOLLOW sets.
2. Remaining productions are placed under FIRST sets.

Conclusion

• Summarized the construction of LL1 parsing table.
• Next session: LL1 parsing technique.

Acknowledgement

• Thank you for attending. Looking forward to next session!