83 lines
2.4 KiB
Dart
83 lines
2.4 KiB
Dart
import 'number-formatter.dart';
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class Calculations {
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static const PERIOD = '.';
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static const MULTIPLY = '*';
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static const SUBTRACT = '-';
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static const ADD = '+';
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static const DIVIDE = '/';
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static const CLEAR = 'CLEAR';
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static const EQUAL = '=';
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static const OPERATIONS = [
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Calculations.ADD,
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Calculations.MULTIPLY,
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Calculations.SUBTRACT,
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Calculations.DIVIDE,
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];
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static double add(double a, double b) => a + b;
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static double subtract(double a, double b) => a - b;
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static double divide(double a, double b) => a / b;
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static double multiply(double a, double b) => a * b;
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}
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class Calculator {
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static String parseString(String text) {
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List<String> numbersToAdd;
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double a, b, result;
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if (text.contains(Calculations.ADD)) {
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numbersToAdd = text.split(Calculations.ADD);
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a = double.parse(numbersToAdd[0]);
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b = double.parse(numbersToAdd[1]);
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result = Calculations.add(a, b);
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} else if (text.contains(Calculations.MULTIPLY)) {
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numbersToAdd = text.split(Calculations.MULTIPLY);
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a = double.parse(numbersToAdd[0]);
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b = double.parse(numbersToAdd[1]);
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result = Calculations.multiply(a, b);
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} else if (text.contains(Calculations.DIVIDE)) {
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numbersToAdd = text.split(Calculations.DIVIDE);
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a = double.parse(numbersToAdd[0]);
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b = double.parse(numbersToAdd[1]);
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result = Calculations.divide(a, b);
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} else if (text.contains(Calculations.SUBTRACT)) {
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numbersToAdd = text.split(Calculations.SUBTRACT);
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a = double.parse(numbersToAdd[0]);
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b = double.parse(numbersToAdd[1]);
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result = Calculations.subtract(a, b);
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} else {
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return text;
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}
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return NumberFormatter.format(result.toString());
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}
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static String addPeriod(String calculatorString) {
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if (calculatorString.isEmpty) {
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return calculatorString = '0${Calculations.PERIOD}';
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}
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RegExp exp = new RegExp(r"\d\.");
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Iterable<Match> matches = exp.allMatches(calculatorString);
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int maxMatches = Calculator.includesOperation(calculatorString) ? 2 : 1;
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return matches.length == maxMatches
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? calculatorString
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: calculatorString += Calculations.PERIOD;
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}
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static bool includesOperation(String calculatorString) {
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for (var operation in Calculations.OPERATIONS) {
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if (calculatorString.contains(operation)) {
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return true;
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}
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}
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return false;
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}
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}
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