WRT error checking: It's a fair cop. I was demonstrating the data structure usage.

As for the destructiveness: It's a feature, not a bug: It avoids redundant evaluation of shared subexpressions.

    -- Chip Salzenberg, Free-Floating Agent of Chaos

In reply to Re: Re (tilly) 2: optimizing a binary expression processor (revised) by chip
in thread optimizing a binary expression processor by princepawn

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