Interactive animation of Dijkstra’s shunting-yard algorithm converting infix expressions to postfix (RPN) using a stack and operator precedence rules.
Key Takeaways
Numbers and variables go directly to output; operators are held on a stack and flushed by precedence and associativity rules.
Left-associative operators trigger early stack flushing when equal-precedence operators follow, preserving correct evaluation order.
Parentheses are used only for grouping: left bracket pushed to stack, right bracket triggers flush, then both are discarded.
Remaining operators on the stack are pushed to output after input is exhausted.
Hacker News Comment Review
Commenters flagged a display bug: multi-digit or adjacent operands like 100+88/4 produce ambiguous RPN output (100884+/) with no delimiter between operands.
One commenter raised a deeper theoretical angle: the animation discards parenthesis tokens, which breaks the model for reversible computing where information cannot be destroyed.
