A Math-Expression Parser in 250 Lines of JavaScript — Recursive Descent, Right-Associative ^, and -2^2 = -4

Every "math evaluator in N lines" article either uses shunting-yard (Dijkstra's stack-based RPN converter) or hand-waves over the hard cases (-2^2, right associativity, error positions). This one uses recursive descent because the grammar and the code map 1-to-1, which makes the whole thing easier to read and write about. ~250 lines of JS, 36 unit tests, supports functions, variables, constants, parentheses, and reports errors with a column number and a caret.

📦 GitHub: — MIT, ~250 lines of JS + 36 unit tests, zero dependencies, no build step.

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