improve type equals

src/compiler/Syntax/Parsing/Parser.cs

@@ -696,11 +696,6 @@ public static class Parser
     {
         if (TryExpectIdentifier(out var name))
         {
-            if (name.Value == "any")
-            {
-                return new NubAnyType();
-            }
-
             if (name.Value == "void")
             {
                 return new NubVoidType();

src/compiler/Syntax/Typing/NubType.cs

@@ -2,7 +2,7 @@
 
 namespace Syntax.Typing;
 
-public abstract class NubType
+public abstract class NubType : IEquatable<NubType>
 {
     public bool Is8BitInteger => this is NubPrimitiveType { Kind: PrimitiveTypeKind.I8 or PrimitiveTypeKind.U8 };
     public bool Is16BitInteger => this is NubPrimitiveType { Kind: PrimitiveTypeKind.I16 or PrimitiveTypeKind.U16 };
@@ -24,48 +24,32 @@ public abstract class NubType
     public bool IsCString => this is NubCStringType;
     public bool IsBool => this is NubPrimitiveType { Kind: PrimitiveTypeKind.Bool };
 
-    public abstract override bool Equals(object? obj);
+    public override bool Equals(object? obj) => obj is NubType other && Equals(other);
+
+    public abstract bool Equals(NubType? other);
     public abstract override int GetHashCode();
     public abstract override string ToString();
+
+    public static bool operator ==(NubType? left, NubType? right) => Equals(left, right);
+    public static bool operator !=(NubType? left, NubType? right) => !Equals(left, right);
 }
 
 public abstract class NubComplexType : NubType;
+
 public abstract class NubSimpleType : NubType;
 
 public class NubCStringType : NubComplexType
 {
-    public override bool Equals(object? obj)
-    {
-        return obj is NubCStringType;
-    }
-
-    public override int GetHashCode()
-    {
-        return "cstring".GetHashCode();
-    }
-
-    public override string ToString()
-    {
-        return "cstring";
-    }
+    public override string ToString() => "cstring";
+    public override bool Equals(NubType? other) => other is NubCStringType;
+    public override int GetHashCode() => HashCode.Combine(typeof(NubCStringType));
 }
 
 public class NubStringType : NubComplexType
 {
-    public override bool Equals(object? obj)
-    {
-        return obj is NubStringType;
-    }
-
-    public override int GetHashCode()
-    {
-        return "string".GetHashCode();
-    }
-
-    public override string ToString()
-    {
-        return "string";
-    }
+    public override string ToString() => "string";
+    public override bool Equals(NubType? other) => other is NubStringType;
+    public override int GetHashCode() => HashCode.Combine(typeof(NubStringType));
 }
 
 public class NubFuncType(NubType returnType, List<NubType> parameters) : NubSimpleType
@@ -73,19 +57,21 @@ public class NubFuncType(NubType returnType, List<NubType> parameters) : NubSimp
     public NubType ReturnType { get; } = returnType;
     public List<NubType> Parameters { get; } = parameters;
 
-    public override bool Equals(object? obj)
-    {
-        return obj is NubFuncType other && other.ReturnType.Equals(ReturnType) && other.Parameters.SequenceEqual(Parameters);
-    }
+    public override string ToString() => $"func({string.Join(", ", Parameters)}): {ReturnType}";
+
+    public override bool Equals(NubType? other) => other is NubFuncType func && ReturnType.Equals(func.ReturnType) && Parameters.SequenceEqual(func.Parameters);
 
     public override int GetHashCode()
     {
-        return HashCode.Combine(ReturnType, Parameters);
+        var hash = new HashCode();
+        hash.Add(typeof(NubFuncType));
+        hash.Add(ReturnType);
+        foreach (var param in Parameters)
+        {
+            hash.Add(param);
         }
 
-    public override string ToString()
-    {
-        return $"func({string.Join(", ", Parameters)}): {ReturnType}";
+        return hash.ToHashCode();
     }
 }
 
@@ -94,95 +80,37 @@ public class NubCustomType(string @namespace, string name) : NubComplexType
     public string Namespace { get; } = @namespace;
     public string Name { get; } = name;
 
-    public override bool Equals(object? obj)
-    {
-        return obj is NubCustomType other && other.Namespace == Namespace && other.Name == Name;
-    }
+    public override string ToString() => $"{Namespace}::{Name}";
 
-    public override int GetHashCode()
-    {
-        return HashCode.Combine(Namespace, Name);
-    }
-
-    public override string ToString()
-    {
-        return $"{Namespace}::{Name}";
-    }
+    public override bool Equals(NubType? other) => other is NubCustomType custom && Namespace == custom.Namespace && Name == custom.Name;
+    public override int GetHashCode() => HashCode.Combine(typeof(NubCustomType), Namespace, Name);
 }
 
 public class NubPointerType(NubType baseType) : NubSimpleType
 {
     public NubType BaseType { get; } = baseType;
 
-    public override bool Equals(object? obj)
-    {
-        return obj is NubPointerType other && BaseType.Equals(other.BaseType);
-    }
+    public override string ToString() => "^" + BaseType;
 
-    public override int GetHashCode()
-    {
-        return HashCode.Combine(BaseType);
-    }
-
-    public override string ToString()
-    {
-        return "^" + BaseType;
-    }
+    public override bool Equals(NubType? other) => other is NubPointerType pointer && BaseType.Equals(pointer.BaseType);
+    public override int GetHashCode() => HashCode.Combine(typeof(NubPointerType), BaseType);
 }
 
 public class NubArrayType(NubType elementType) : NubComplexType
 {
     public NubType ElementType { get; } = elementType;
 
-    public override bool Equals(object? obj)
-    {
-        if (obj is NubArrayType other)
-        {
-            return ElementType.Equals(other.ElementType);
-        }
+    public override string ToString() => "[]" + ElementType;
 
-        return false;
-    }
-
-    public override int GetHashCode()
-    {
-        return HashCode.Combine(ElementType);
-    }
-
-    public override string ToString()
-    {
-        return "[]" + ElementType;
-    }
-}
-
-public class NubAnyType : NubSimpleType
-{
-    public override string ToString() => "any";
-
-    public override bool Equals(object? obj)
-    {
-        return obj is NubAnyType;
-    }
-
-    public override int GetHashCode()
-    {
-        return "any".GetHashCode();
-    }
+    public override bool Equals(NubType? other) => other is NubArrayType array && ElementType.Equals(array.ElementType);
+    public override int GetHashCode() => HashCode.Combine(typeof(NubArrayType), ElementType);
 }
 
 public class NubVoidType : NubSimpleType
 {
     public override string ToString() => "void";
-
-    public override bool Equals(object? obj)
-    {
-        return obj is NubVoidType;
-    }
-
-    public override int GetHashCode()
-    {
-        return GetType().GetHashCode();
-    }
+    public override bool Equals(NubType? other) => other is NubVoidType;
+    public override int GetHashCode() => HashCode.Combine(typeof(NubVoidType));
 }
 
 public class NubPrimitiveType(PrimitiveTypeKind kind) : NubSimpleType
@@ -225,16 +153,6 @@ public class NubPrimitiveType(PrimitiveTypeKind kind) : NubSimpleType
         return kind != null;
     }
 
-    public override bool Equals(object? obj)
-    {
-        return obj is NubPrimitiveType other && other.Kind == Kind;
-    }
-
-    public override int GetHashCode()
-    {
-        return HashCode.Combine(Kind);
-    }
-
     public override string ToString()
     {
         return Kind switch
@@ -256,6 +174,9 @@ public class NubPrimitiveType(PrimitiveTypeKind kind) : NubSimpleType
             _ => throw new ArgumentOutOfRangeException(nameof(kind), Kind, null)
         };
     }
+
+    public override bool Equals(NubType? other) => other is NubPrimitiveType primitive && primitive.Kind == Kind;
+    public override int GetHashCode() => HashCode.Combine(typeof(NubPrimitiveType), Kind.GetHashCode());
 }
 
 public enum PrimitiveTypeKind