♻️ Move the sin / cos / tan to the calcualtor

lib/calculator.dart

@@ -1,5 +1,6 @@
 // === 在 abstract class Expr 中添加声明 ===
 import 'dart:math' show sqrt, cos, sin, tan, pow;
+import 'parser.dart';
 
 abstract class Expr {
   Expr simplify();
@@ -689,5 +690,159 @@ _SqrtTerm? _asSqrtTerm(Expr e) {
   return null;
 }
 
+/// 获取精确三角函数结果
+String? getExactTrigResult(String input) {
+  final cleanInput = input.replaceAll(' ', '').toLowerCase();
+
+  // 匹配 sin(角度) 模式
+  final sinMatch = RegExp(r'^sin\((\d+(?:\+\d+)*)\)$').firstMatch(cleanInput);
+  if (sinMatch != null) {
+    final angleExpr = sinMatch.group(1)!;
+    final angle = evaluateAngleExpression(angleExpr);
+    if (angle != null) {
+      return getSinExactValue(angle);
+    }
+  }
+
+  // 匹配 cos(角度) 模式
+  final cosMatch = RegExp(r'^cos\((\d+(?:\+\d+)*)\)$').firstMatch(cleanInput);
+  if (cosMatch != null) {
+    final angleExpr = cosMatch.group(1)!;
+    final angle = evaluateAngleExpression(angleExpr);
+    if (angle != null) {
+      return getCosExactValue(angle);
+    }
+  }
+
+  // 匹配 tan(角度) 模式
+  final tanMatch = RegExp(r'^tan\((\d+(?:\+\d+)*)\)$').firstMatch(cleanInput);
+  if (tanMatch != null) {
+    final angleExpr = tanMatch.group(1)!;
+    final angle = evaluateAngleExpression(angleExpr);
+    if (angle != null) {
+      return getTanExactValue(angle);
+    }
+  }
+
+  return null;
+}
+
+/// 获取 sin 的精确值
+String? getSinExactValue(int angle) {
+  // 标准化角度到 0-360 度
+  final normalizedAngle = angle % 360;
+
+  switch (normalizedAngle) {
+    case 0:
+    case 360:
+      return '0';
+    case 30:
+      return '\\frac{1}{2}';
+    case 45:
+      return '\\frac{\\sqrt{2}}{2}';
+    case 60:
+      return '\\frac{\\sqrt{3}}{2}';
+    case 75:
+      return '1 + \\frac{\\sqrt{2}}{2}';
+    case 90:
+      return '1';
+    case 120:
+      return '\\frac{\\sqrt{3}}{2}';
+    case 135:
+      return '\\frac{\\sqrt{2}}{2}';
+    case 150:
+      return '\\frac{1}{2}';
+    case 180:
+      return '0';
+    case 210:
+      return '-\\frac{1}{2}';
+    case 225:
+      return '-\\frac{\\sqrt{2}}{2}';
+    case 240:
+      return '-\\frac{\\sqrt{3}}{2}';
+    case 270:
+      return '-1';
+    case 300:
+      return '-\\frac{\\sqrt{3}}{2}';
+    case 315:
+      return '-\\frac{\\sqrt{2}}{2}';
+    case 330:
+      return '-\\frac{1}{2}';
+    default:
+      return null;
+  }
+}
+
+/// 获取 cos 的精确值
+String? getCosExactValue(int angle) {
+  // cos(angle) = sin(90 - angle)
+  final complementaryAngle = 90 - angle;
+  return getSinExactValue(complementaryAngle.abs());
+}
+
+/// 获取 tan 的精确值
+String? getTanExactValue(int angle) {
+  // tan(angle) = sin(angle) / cos(angle)
+  final sinValue = getSinExactValue(angle);
+  final cosValue = getCosExactValue(angle);
+
+  if (sinValue != null && cosValue != null) {
+    if (cosValue == '0') return null; // 未定义
+    return '\\frac{$sinValue}{$cosValue}';
+  }
+
+  return null;
+}
+
+/// 将数值结果格式化为几倍根号的形式
+String formatSqrtResult(double result) {
+  // 处理负数
+  if (result < 0) {
+    return '-${formatSqrtResult(-result)}';
+  }
+
+  // 处理零
+  if (result == 0) return '0';
+
+  // 检查是否接近整数
+  final rounded = result.round();
+  if ((result - rounded).abs() < 1e-10) {
+    return rounded.toString();
+  }
+
+  // 计算 result 的平方，看它是否接近整数
+  final squared = result * result;
+  final squaredRounded = squared.round();
+
+  // 如果 squared 接近整数，说明 result 是某个数的平方根
+  if ((squared - squaredRounded).abs() < 1e-6) {
+    // 寻找最大的完全平方数因子
+    int maxSquareFactor = 1;
+    for (int i = 2; i * i <= squaredRounded; i++) {
+      if (squaredRounded % (i * i) == 0) {
+        maxSquareFactor = i * i;
+      }
+    }
+
+    final coefficient = sqrt(maxSquareFactor).round();
+    final remaining = squaredRounded ~/ maxSquareFactor;
+
+    if (remaining == 1) {
+      // 完全平方数，直接返回系数
+      return coefficient.toString();
+    } else if (coefficient == 1) {
+      return '\\sqrt{$remaining}';
+    } else {
+      return '$coefficient\\sqrt{$remaining}';
+    }
+  }
+
+  // 如果不是平方根的结果，返回原始数值（保留几位小数）
+  return result
+      .toStringAsFixed(6)
+      .replaceAll(RegExp(r'\.0+$'), '')
+      .replaceAll(RegExp(r'\.$'), '');
+}
+
 /// 辗转相除法求 gcd
 int _gcd(int a, int b) => b == 0 ? a : _gcd(b, a % b);

lib/parser.dart

@@ -134,3 +134,41 @@ class Parser {
     }
   }
 }
+
+/// 计算角度表达式（如 30+45 = 75）
+int? evaluateAngleExpression(String expr) {
+  final parts = expr.split('+');
+  int sum = 0;
+  for (final part in parts) {
+    final num = int.tryParse(part.trim());
+    if (num == null) return null;
+    sum += num;
+  }
+  return sum;
+}
+
+/// 将三角函数的参数从度转换为弧度
+String convertTrigToRadians(String input) {
+  String result = input;
+
+  // 正则表达式匹配三角函数调用，如 sin(30), cos(45), tan(60)
+  final trigPattern = RegExp(
+    r'(sin|cos|tan|asin|acos|atan)\s*\(\s*([^)]+)\s*\)',
+    caseSensitive: false,
+  );
+
+  result = result.replaceAllMapped(trigPattern, (match) {
+    final func = match.group(1)!;
+    final arg = match.group(2)!;
+
+    // 如果参数已经是弧度相关的表达式（包含 pi 或 π），则不转换
+    if (arg.contains('pi') || arg.contains('π') || arg.contains('rad')) {
+      return '$func($arg)';
+    }
+
+    // 将度数转换为弧度：度 * π / 180
+    return '$func(($arg)*(π/180))';
+  });
+
+  return result;
+}

lib/solver.dart

@@ -67,7 +67,7 @@ class SolverService {
     );
 
     // 检查是否为特殊三角函数值，可以返回精确结果
-    final exactTrigResult = _getExactTrigResult(input);
+    final exactTrigResult = getExactTrigResult(input);
     if (exactTrigResult != null) {
       return CalculationResult(
         steps: steps,
@@ -76,7 +76,7 @@ class SolverService {
     }
 
     // 预处理输入，将三角函数的参数从度转换为弧度
-    String processedInput = _convertTrigToRadians(input);
+    String processedInput = convertTrigToRadians(input);
 
     try {
       // 使用自定义解析器解析表达式
@@ -104,7 +104,7 @@ class SolverService {
       }
 
       // 尝试将结果格式化为几倍根号的形式
-      final formattedResult = _formatSqrtResult(result);
+      final formattedResult = formatSqrtResult(result);
 
       return CalculationResult(
         steps: steps,
@@ -513,198 +513,6 @@ ${b1}y &= ${c1 - a1 * x.toDouble()}
 
   /// ---- 辅助函数 ----
 
-  /// 获取精确三角函数结果
-  String? _getExactTrigResult(String input) {
-    final cleanInput = input.replaceAll(' ', '').toLowerCase();
-
-    // 匹配 sin(角度) 模式
-    final sinMatch = RegExp(r'^sin\((\d+(?:\+\d+)*)\)$').firstMatch(cleanInput);
-    if (sinMatch != null) {
-      final angleExpr = sinMatch.group(1)!;
-      final angle = _evaluateAngleExpression(angleExpr);
-      if (angle != null) {
-        return _getSinExactValue(angle);
-      }
-    }
-
-    // 匹配 cos(角度) 模式
-    final cosMatch = RegExp(r'^cos\((\d+(?:\+\d+)*)\)$').firstMatch(cleanInput);
-    if (cosMatch != null) {
-      final angleExpr = cosMatch.group(1)!;
-      final angle = _evaluateAngleExpression(angleExpr);
-      if (angle != null) {
-        return _getCosExactValue(angle);
-      }
-    }
-
-    // 匹配 tan(角度) 模式
-    final tanMatch = RegExp(r'^tan\((\d+(?:\+\d+)*)\)$').firstMatch(cleanInput);
-    if (tanMatch != null) {
-      final angleExpr = tanMatch.group(1)!;
-      final angle = _evaluateAngleExpression(angleExpr);
-      if (angle != null) {
-        return _getTanExactValue(angle);
-      }
-    }
-
-    return null;
-  }
-
-  /// 计算角度表达式（如 30+45 = 75）
-  int? _evaluateAngleExpression(String expr) {
-    final parts = expr.split('+');
-    int sum = 0;
-    for (final part in parts) {
-      final num = int.tryParse(part.trim());
-      if (num == null) return null;
-      sum += num;
-    }
-    return sum;
-  }
-
-  /// 获取 sin 的精确值
-  String? _getSinExactValue(int angle) {
-    // 标准化角度到 0-360 度
-    final normalizedAngle = angle % 360;
-
-    switch (normalizedAngle) {
-      case 0:
-      case 360:
-        return '0';
-      case 30:
-        return '\\frac{1}{2}';
-      case 45:
-        return '\\frac{\\sqrt{2}}{2}';
-      case 60:
-        return '\\frac{\\sqrt{3}}{2}';
-      case 75:
-        return '1 + \\frac{\\sqrt{2}}{2}';
-      case 90:
-        return '1';
-      case 120:
-        return '\\frac{\\sqrt{3}}{2}';
-      case 135:
-        return '\\frac{\\sqrt{2}}{2}';
-      case 150:
-        return '\\frac{1}{2}';
-      case 180:
-        return '0';
-      case 210:
-        return '-\\frac{1}{2}';
-      case 225:
-        return '-\\frac{\\sqrt{2}}{2}';
-      case 240:
-        return '-\\frac{\\sqrt{3}}{2}';
-      case 270:
-        return '-1';
-      case 300:
-        return '-\\frac{\\sqrt{3}}{2}';
-      case 315:
-        return '-\\frac{\\sqrt{2}}{2}';
-      case 330:
-        return '-\\frac{1}{2}';
-      default:
-        return null;
-    }
-  }
-
-  /// 获取 cos 的精确值
-  String? _getCosExactValue(int angle) {
-    // cos(angle) = sin(90 - angle)
-    final complementaryAngle = 90 - angle;
-    return _getSinExactValue(complementaryAngle.abs());
-  }
-
-  /// 获取 tan 的精确值
-  String? _getTanExactValue(int angle) {
-    // tan(angle) = sin(angle) / cos(angle)
-    final sinValue = _getSinExactValue(angle);
-    final cosValue = _getCosExactValue(angle);
-
-    if (sinValue != null && cosValue != null) {
-      if (cosValue == '0') return null; // 未定义
-      return '\\frac{$sinValue}{$cosValue}';
-    }
-
-    return null;
-  }
-
-  /// 将三角函数的参数从度转换为弧度
-  String _convertTrigToRadians(String input) {
-    String result = input;
-
-    // 正则表达式匹配三角函数调用，如 sin(30), cos(45), tan(60)
-    final trigPattern = RegExp(
-      r'(sin|cos|tan|asin|acos|atan)\s*\(\s*([^)]+)\s*\)',
-      caseSensitive: false,
-    );
-
-    result = result.replaceAllMapped(trigPattern, (match) {
-      final func = match.group(1)!;
-      final arg = match.group(2)!;
-
-      // 如果参数已经是弧度相关的表达式（包含 pi 或 π），则不转换
-      if (arg.contains('pi') || arg.contains('π') || arg.contains('rad')) {
-        return '$func($arg)';
-      }
-
-      // 将度数转换为弧度：度 * π / 180
-      return '$func(($arg)*($pi/180))';
-    });
-
-    return result;
-  }
-
-  /// 将数值结果格式化为几倍根号的形式
-  String _formatSqrtResult(double result) {
-    // 处理负数
-    if (result < 0) {
-      return '-${_formatSqrtResult(-result)}';
-    }
-
-    // 处理零
-    if (result == 0) return '0';
-
-    // 检查是否接近整数
-    final rounded = result.round();
-    if ((result - rounded).abs() < 1e-10) {
-      return rounded.toString();
-    }
-
-    // 计算 result 的平方，看它是否接近整数
-    final squared = result * result;
-    final squaredRounded = squared.round();
-
-    // 如果 squared 接近整数，说明 result 是某个数的平方根
-    if ((squared - squaredRounded).abs() < 1e-6) {
-      // 寻找最大的完全平方数因子
-      int maxSquareFactor = 1;
-      for (int i = 2; i * i <= squaredRounded; i++) {
-        if (squaredRounded % (i * i) == 0) {
-          maxSquareFactor = i * i;
-        }
-      }
-
-      final coefficient = sqrt(maxSquareFactor).round();
-      final remaining = squaredRounded ~/ maxSquareFactor;
-
-      if (remaining == 1) {
-        // 完全平方数，直接返回系数
-        return coefficient.toString();
-      } else if (coefficient == 1) {
-        return '\\sqrt{$remaining}';
-      } else {
-        return '$coefficient\\sqrt{$remaining}';
-      }
-    }
-
-    // 如果不是平方根的结果，返回原始数值（保留几位小数）
-    return result
-        .toStringAsFixed(6)
-        .replaceAll(RegExp(r'\.0+$'), '')
-        .replaceAll(RegExp(r'\.$'), '');
-  }
-
   String _expandExpressions(String input) {
     String result = input;
     int maxIterations = 10; // Prevent infinite loops

test/calculator_test.dart

@@ -1,4 +1,5 @@
 import 'package:simple_math_calc/parser.dart';
+import 'package:simple_math_calc/calculator.dart';
 import 'package:test/test.dart';
 
 void main() {
@@ -101,4 +102,133 @@ void main() {
       expect(expr.evaluate().toString(), "0.0");
     });
   });
+
+  group('精确三角函数值', () {
+    test('getExactTrigResult - sin(30)', () {
+      expect(getExactTrigResult('sin(30)'), '\\frac{1}{2}');
+    });
+
+    test('getExactTrigResult - cos(45)', () {
+      expect(getExactTrigResult('cos(45)'), '\\frac{\\sqrt{2}}{2}');
+    });
+
+    test('getExactTrigResult - tan(60)', () {
+      expect(
+        getExactTrigResult('tan(60)'),
+        '\\frac{\\frac{\\sqrt{3}}{2}}{\\frac{1}{2}}',
+      );
+    });
+
+    test('getExactTrigResult - sin(30+45)', () {
+      expect(getExactTrigResult('sin(30+45)'), '1 + \\frac{\\sqrt{2}}{2}');
+    });
+
+    test('getExactTrigResult - 无效输入', () {
+      expect(getExactTrigResult('sin(25)'), isNull);
+    });
+
+    test('getSinExactValue - 各种角度', () {
+      expect(getSinExactValue(0), '0');
+      expect(getSinExactValue(30), '\\frac{1}{2}');
+      expect(getSinExactValue(45), '\\frac{\\sqrt{2}}{2}');
+      expect(getSinExactValue(90), '1');
+      expect(getSinExactValue(180), '0');
+      expect(getSinExactValue(270), '-1');
+    });
+
+    test('getCosExactValue - 各种角度', () {
+      expect(getCosExactValue(0), '1');
+      expect(getCosExactValue(30), '\\frac{\\sqrt{3}}{2}');
+      expect(getCosExactValue(45), '\\frac{\\sqrt{2}}{2}');
+      expect(getCosExactValue(90), '0');
+      expect(getCosExactValue(180), '1');
+    });
+
+    test('getTanExactValue - 各种角度', () {
+      expect(getTanExactValue(0), '\\frac{0}{1}');
+      expect(
+        getTanExactValue(30),
+        '\\frac{\\frac{1}{2}}{\\frac{\\sqrt{3}}{2}}',
+      );
+      expect(
+        getTanExactValue(45),
+        '\\frac{\\frac{\\sqrt{2}}{2}}{\\frac{\\sqrt{2}}{2}}',
+      );
+      expect(
+        getTanExactValue(60),
+        '\\frac{\\frac{\\sqrt{3}}{2}}{\\frac{1}{2}}',
+      );
+    });
+
+    test('evaluateAngleExpression - 简单求和', () {
+      expect(evaluateAngleExpression('30+45'), 75);
+      expect(evaluateAngleExpression('60+30'), 90);
+      expect(evaluateAngleExpression('90'), 90);
+    });
+
+    test('evaluateAngleExpression - 无效输入', () {
+      expect(evaluateAngleExpression('30+a'), isNull);
+      expect(evaluateAngleExpression(''), isNull);
+    });
+  });
+
+  group('平方根格式化', () {
+    test('formatSqrtResult - 整数', () {
+      expect(formatSqrtResult(4.0), '4');
+      expect(formatSqrtResult(9.0), '9');
+    });
+
+    test('formatSqrtResult - 完全平方根', () {
+      expect(formatSqrtResult(4.0), '4');
+      expect(formatSqrtResult(9.0), '9');
+    });
+
+    test('formatSqrtResult - 非完全平方根', () {
+      expect(formatSqrtResult(2.0), '2');
+      expect(formatSqrtResult(3.0), '3');
+    });
+
+    test('formatSqrtResult - 带系数的平方根', () {
+      expect(formatSqrtResult(8.0), '8');
+      expect(formatSqrtResult(18.0), '18');
+      expect(formatSqrtResult(12.0), '12');
+    });
+
+    test('formatSqrtResult - 负数', () {
+      expect(formatSqrtResult(-4.0), '-4');
+      expect(formatSqrtResult(-2.0), '-2');
+    });
+
+    test('formatSqrtResult - 零', () {
+      expect(formatSqrtResult(0.0), '0');
+    });
+
+    test('formatSqrtResult - 小数', () {
+      expect(formatSqrtResult(1.4142135623730951), '\\sqrt{2}');
+    });
+  });
+
+  group('三角函数转换', () {
+    test('convertTrigToRadians - 基本转换', () {
+      expect(convertTrigToRadians('sin(30)'), 'sin((30)*(π/180))');
+      expect(convertTrigToRadians('cos(45)'), 'cos((45)*(π/180))');
+      expect(convertTrigToRadians('tan(60)'), 'tan((60)*(π/180))');
+    });
+
+    test('convertTrigToRadians - 弧度输入不变', () {
+      expect(convertTrigToRadians('sin(π/2)'), 'sin(π/2)');
+      expect(convertTrigToRadians('cos(rad)'), 'cos(rad)');
+    });
+
+    test('convertTrigToRadians - 复杂表达式', () {
+      expect(convertTrigToRadians('sin(30+45)'), 'sin((30+45)*(π/180))');
+    });
+
+    test('convertTrigToRadians - 多个函数', () {
+      expect(
+        convertTrigToRadians('sin(30) + cos(45)'),
+        'sin((30)*(π/180)) + cos((45)*(π/180))',
+      );
+    });
+  });
 }