Use INumer<T> for the parser

ewdlop · Sep 26, 2023 · f04f0db · f04f0db
1 parent e32153e
commit f04f0db
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Showing 6 changed files with 46 additions and 35 deletions.
diff --git a/ConsoleApp8/BinOp.cs b/ConsoleApp8/BinOp.cs
@@ -1,8 +1,11 @@
-namespace ConsoleApp8;
+using System.Numerics;
 
-public record BinOp(AST Left, Token Op, AST Right) : AST
+namespace ConsoleApp8;
+
+public record BinOp<T>(AST<T> Left, Token Op, AST<T> Right) : AST<T> 
+    where T: INumber<T>
 {
-    public override T Accept<T>(IASTVisitor<T> visitor)
+    public override T Accept(IASTVisitor<T> visitor)
     {
         return visitor.VisitBinOp(this);
     }

diff --git a/ConsoleApp8/Evaluator.cs b/ConsoleApp8/Evaluator.cs
@@ -1,8 +1,11 @@
-namespace ConsoleApp8;
+using System.Globalization;
+using System.Numerics;
 
-public class Evaluator : IASTVisitor<double>
+namespace ConsoleApp8;
+
+public class Evaluator<T> : IASTVisitor<T> where T : INumber<T>
 {
-    public double VisitBinOp(BinOp binOp)
+    public T VisitBinOp(BinOp<T> binOp)
     {
         if (binOp.Op.Type == TokenType.Plus)
             return binOp.Left.Accept(this) + binOp.Right.Accept(this);
@@ -16,8 +19,8 @@ public double VisitBinOp(BinOp binOp)
         throw new Exception($"Unknown operator: {binOp.Op.Type}");
     }
 
-    public double VisitNum(Num num)
+    public T VisitNum(Num<T> num)
     {
-        return double.Parse(num.Value.Value ?? string.Empty);
+        return T.TryParse(num.Value.Value ?? string.Empty, CultureInfo.CurrentCulture.NumberFormat,out T? result) ? result : T.Zero;
     }
 }
diff --git a/ConsoleApp8/IASTVisitor.cs b/ConsoleApp8/IASTVisitor.cs
@@ -1,12 +1,14 @@
-namespace ConsoleApp8;
+using System.Numerics;
 
-public interface IASTVisitor<T>
+namespace ConsoleApp8;
+
+public interface IASTVisitor<T> where T : INumber<T>
 {
-    T VisitBinOp(BinOp binOp);
-    T VisitNum(Num num);
+    T VisitBinOp(BinOp<T> binOp);
+    T VisitNum(Num<T> num);
 }
 
-public abstract record AST
+public abstract record AST<T> where T : INumber<T>
 {
-    public abstract T Accept<T>(IASTVisitor<T> visitor);
+    public abstract T Accept(IASTVisitor<T> visitor);
 }
diff --git a/ConsoleApp8/Num.cs b/ConsoleApp8/Num.cs
@@ -1,8 +1,10 @@
-namespace ConsoleApp8;
+using System.Numerics;
 
-public record Num(Token Value) : AST
+namespace ConsoleApp8;
+
+public record Num<T>(Token Value) : AST<T> where T : INumber<T>
 {
-    public override T Accept<T>(IASTVisitor<T> visitor)
+    public override T Accept(IASTVisitor<T> visitor)
     {
         return visitor.VisitNum(this);
     }

diff --git a/ConsoleApp8/Parser.cs b/ConsoleApp8/Parser.cs
@@ -1,17 +1,18 @@
-namespace ConsoleApp8;
+using System.Numerics;
 
-public class Parser(Lexer lexer)
+namespace ConsoleApp8;
+
+public class Parser<T>(Lexer lexer) where T : INumber<T>
 {
     private Token currentToken = lexer.GetNextToken();
     public Token CurrentToken => currentToken;
-    // Corresponds to EXPRESSION -> TERM '+' EXPRESSION | TERM
-    public AST Expression()
+    public AST<T> Expression()
     {
-        var node = Term();
+        AST<T> node = Term();
 
         while (CurrentToken.Type == TokenType.Plus || CurrentToken.Type == TokenType.Minus)
         {
-            var token = CurrentToken;
+            Token token = CurrentToken;
             if (token.Type == TokenType.Plus)
             {
                 Eat(TokenType.Plus);
@@ -21,15 +22,15 @@ public AST Expression()
                 Eat(TokenType.Minus);
             }
 
-            node = new BinOp(node, token, Term());
+            node = new BinOp<T>(node, token, Term());
         }
 
         return node;
     }
 
-    public AST Term()
+    public AST<T> Term()
     {
-        var node = Factor();
+        AST<T> node = Factor();
 
         while (CurrentToken.Type == TokenType.Times || CurrentToken.Type == TokenType.Div)
         {
@@ -43,33 +44,33 @@ public AST Term()
                 Eat(TokenType.Div);
             }
 
-            node = new BinOp(node, token, Factor());
+            node = new BinOp<T>(node, token, Factor());
         }
 
         return node;
     }
 
-    public AST Factor()
+    public AST<T> Factor()
     {
-        var token = CurrentToken;
+        Token token = CurrentToken;
 
         if (token.Type == TokenType.Number)
         {
             Eat(TokenType.Number);
-            return new Num(token);
+            return new Num<T>(token);
         }
         else if (token.Type == TokenType.LeftParenthesis)
         {
             Eat(TokenType.LeftParenthesis);
-            var node = Expression();
+            AST<T> node = Expression();
             Eat(TokenType.RightParenthesis);
             return node;
         }
 
         throw new Exception("Syntax Error");
     }
 
-    public AST Parse()
+    public AST<T> Parse()
     {
         return Expression();
     }

diff --git a/ConsoleApp8/Program.cs b/ConsoleApp8/Program.cs
@@ -2,9 +2,9 @@
 
 string input = "(3+5)*2";
 Lexer lexer = new Lexer(input);
-Parser parser = new Parser(lexer);
-AST tree = parser.Parse();
+Parser<double> parser = new Parser<double>(lexer);
+AST<double> tree = parser.Parse();
 
-Evaluator evaluator = new Evaluator();
+Evaluator<double> evaluator = new Evaluator<double>();
 double result = tree.Accept(evaluator);
 Console.WriteLine(result);  // Outputs: 16