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dgageot/RPN

Created August 4, 2010 18:18
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RPN
foldingFunction=method(sum, x,
case(x,
"+", [sum pop! + sum pop!],
"*", [sum pop! * sum pop!],
"-", [sum pop! - sum pop!],
"/", [sum pop! / sum pop!],
[x toRational]
) + sum
)
"8 1 2 + 5 * +" split fold([], sum, x, foldingFunction(sum, x)) println
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dgageot commented Aug 5, 2010

List foldingFunction = method(x,
append!(case(x,
or("+", "*", "-", "/"), Message fromText(x) appendArgument(pop!) sendTo(pop!),
x toRational
)
)
)
"8 1 2 + 5 * +" split prepend!([]) fold(foldingFunction) println

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