PLShell - Interactive Parsing Shell 🖥️📖

PLShell is an interactive shell for grammar analysis and parsing. It supports FIRST, FOLLOW, LL(1) table construction, SLR(1) automaton generation, and input validation.
Designed for both analysis and education, it provides step-by-step explanations to help visualize parsing processes.

🚀 Features

✅ Load grammars from files (load grammar.txt)
✅ Compute LL(1) components:

• first: Compute the First set of a given string.
• follow: Compute the Follow set of a given non-terminal.
• predsymbols: Compute the Prediction Symbols of a rule.
• ll1: Checks whether the grammar is LL(1) and display the table.

✅ Coming soon: Generate SLR(1) automaton and visualize states
✅ Coming soon: Parse and validate input strings
✅ Verbose mode: Add -v or --verbose to any command to get a step-by-step explanation, useful for learning purposes. ✅ Shell environment: Run multiple commands interactively.

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📥 Compiling

🔧 Requirements

• C++20 or later
• Boost.ProgramOptions (for command parsing)

Usage

Once inside pl-shell you can execute commands:

• Load a grammar

load my_grammar.txt

• Compute First set:

first ABC
first ABC -v

• Compute Follow set:

follow A
follow A -v

• Compute Prediction Symbols:

predsymbols A BC
predsymbols A BC -v

• Check if the grammar is LL(1):

ll1
ll1 -v