27 lines
1.1 KiB
Text
27 lines
1.1 KiB
Text
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def ops: ['+','-','*','/'];
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data binaryExpression <{left: <node>, op: <?($ops <[<=$::raw>]>)>, right: <node>}>
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data node <binaryExpression|"1">
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composer parseArithmetic
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(<WS>?) <addition|multiplication|term> (<WS>?)
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rule addition: {left:<addition|multiplication|term> (<WS>?) op:<'[+-]'> (<WS>?) right:<multiplication|term>}
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rule multiplication: {left:<multiplication|term> (<WS>?) op:<'[*/]'> (<WS>?) right:<term>}
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rule term: <INT"1"|parentheses>
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rule parentheses: (<'\('> <WS>?) <addition|multiplication|term> (<WS>? <'\)'>)
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end parseArithmetic
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templates evaluateArithmetic
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<´node´ {op: <='+'>}> ($.left -> evaluateArithmetic) + ($.right -> evaluateArithmetic) !
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<´node´ {op: <='-'>}> ($.left -> evaluateArithmetic) - ($.right -> evaluateArithmetic) !
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<´node´ {op: <='*'>}> ($.left -> evaluateArithmetic) * ($.right -> evaluateArithmetic) !
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<´node´ {op: <='/'>}> ($.left -> evaluateArithmetic) ~/ ($.right -> evaluateArithmetic) !
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otherwise $ !
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end evaluateArithmetic
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def ast: '(100 - 5 * (2+3*4) + 2) / 2' -> parseArithmetic;
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'$ast;
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' -> !OUT::write
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'$ast -> evaluateArithmetic;
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' -> !OUT::write
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