53 lines
1 KiB
Dart
53 lines
1 KiB
Dart
void main() {}
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/*
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void main() {
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var number = match( RegExp(r'-?[0-9]+(\.[0-9]+)?'))
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.map<num>((r) => num.parse(r.span.text));
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var term = reference<num>();
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var r = Recursion<num>();
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r.prefix = [number];
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r.infix.addAll({
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match('*'): (l, r, _) => l * r,
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match('/'): (l, r, _) => l / r,
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match('+'): (l, r, _) => l + r,
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match('-'): (l, r, _) => l - r,
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match('-'): (l, r, _) => l - r,
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match('+'): (l, r, _) => l + r,
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match('/'): (l, r, _) => l / r,
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match('*'): (l, r, _) => l * r,
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});
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term.parser = r.precedence(0);
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num parse(String text) {
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var scanner = SpanScanner(text);
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var result = term.parse(scanner);
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print(result.span.highlight());
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return result.value;
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}
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test('prefix', () {
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expect(parse('24'), 24);
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});
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test('infix', () {
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expect(parse('12/6'), 2);
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expect(parse('24+23'), 47);
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expect(parse('24-23'), 1);
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expect(parse('4*3'), 12);
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});
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test('precedence', () {
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expect(parse('2+3*5*2'), 15);
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//expect(parse('2+3+5-2*2'), 15);
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});
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}
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*/
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