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