Building an AST-Driven Propositional Truth Table Generator in JavaScript

Writing a simple boolean parser using JavaScript's built-in eval() is risky, error-prone, and doesn't support structured mathematical logic operators like material implication or biconditionals.

I built a lightweight, client-side discrete logic generator that constructs an Abstract Syntax Tree (AST) to evaluate expressions step by step.

How the Parser Works

• Lexical Analysis: The scanner tokenizes raw input strings, recognizing variables ($p, q, r$), parentheses, and logical operators (AND, OR, NOT, XOR, IMPLIES, EQUIV).
• Operator Precedence: Using the Shunting-Yard algorithm, infix notation is converted to an evaluation-ready syntax tree that preserves mathematical order of operations.
• Exhaustive Evaluation: The engine iterates across all $2^n$ binary permutations, evaluating truth values across intermediate subexpression branches.

Features

• Step-by-step intermediate truth table columns for verification.
• Automated detection of tautologies, contradictions, and contingencies.
• Fully client-side computation with zero latency.

Try the logic generator here: Truth Table Generator

What's your preferred approach for parsing nested logical grammar in JavaScript? Let me know in the comments!