make exceptions cooler and fix example code

compiler/example.mew

@@ -2,18 +2,18 @@ import "std:strings";
 import "foo" as bar;
 import "./foobar";
 
-/*
+
 fn foo() {}
 
-pub fn bar(int x) -> int {}
+pub fn bar(x: int): int {}
 
-pub fn multiret() -> int, int {}
+pub fn multiret(): int, int {}
 
-[c_export] pub fn add(int a, int b) -> int {}
+[c_export] pub fn add(a: int, b: int): int {}
 
-[c_export("add_floats")] pub fn add(float a, float b) -> float {}
+[c_export("add_floats")] pub fn add(a: float,b:  float): float {}
 
-fn sub<T>(T a, T b) -> T
+fn sub<T>(a: T, b: T): T
     where SUBTRACT T 
 {
     // do something
@@ -21,19 +21,19 @@ fn sub<T>(T a, T b) -> T
 
 
 
-fn ret_arr() -> [int; 10] {}
-fn ret_slice() -> [int] {}
-fn ret_multislice() -> [[int]] {}
-fn ret_ptr() -> int* {}
-fn ret_ptrslice() -> [int*] {}
-fn ret_arrayptr() -> [int; 5]* {}
-fn ret_tuple() -> (int, int) {}
+fn ret_arr(): [int; 10] {}
+fn ret_slice(): [int] {}
+fn ret_multislice(): [[int]] {}
+fn ret_ptr(): int* {}
+fn ret_ptrslice(): [int*] {}
+fn ret_arrayptr(): [int; 5]* {}
+fn ret_tuple(): (int, int) {}
 
-fn ret_imported() -> strings:StringBuilder {}
+fn ret_imported(): strings:StringBuilder {}
 
-fn ret_nested() -> foo@bar {}
+fn ret_nested(): foo@bar {}
 
-fn ret_imported_nested() -> foo:bar@some@nested@shit {}
+fn ret_imported_nested(): foo:bar@some@nested@shit {}
 
 
 constraint Foo A {
@@ -47,10 +47,7 @@ constraint Bar B {
     constraint Foo SomeType<B>;
 }
 
-*/
 
-
-/*
 struct Foo {
     something: int;
     bar: struct {
@@ -65,13 +62,13 @@ enum X {
     C
 }
 
-enum X<T1, T2, T3> {
+enum X1<T1, T2, T3> {
     A(T1),
     B(T2),
     C(T3),
 }
 
-enum X<T1, T2, T3> where Constraint T1 T2 where Constraint T2 T3 {
+enum X2<T1, T2, T3> where Constraint T1 T2 where Constraint T2 T3 {
     A(T1),
     B(T2),
     C(T3),
@@ -91,14 +88,12 @@ type F<X> = Foo<Bar<X>>;
 
 
 
-type X = [Y; 10];
+type Xa = [Y; 10];
 
-*/
-/*
-tuple X<A> (A,A,A);
+tuple Xa<A> (A,A,A);
 
 
-type X<T> = [T; 10];
+type Xaa<T> = [T; 10];
 type X<T1, T2> = (T1, T2);
 
 fn foo() {
@@ -132,7 +127,7 @@ struct Bar {
 }
 
 
-struct Foo {
+struct Fooo {
     x: enum {Foo, Bar};
 }
 
@@ -175,15 +170,13 @@ fn test() {
 
 
 
-type A = int*;
+type Aaaaa = int*;
 
 struct B {
     x: (int, int);
-}*/
+}
 
-type A<T> = [(T,int); 10];
-
-struct A<T> {
+struct Aaaaa<T> {
     x: B<T>;
     y: s32;
 }

parser/ExpressionVisitorNya.cs

@@ -25,7 +25,7 @@ public class ExpressionVisitorNya : MeowBaseVisitorNya<ExpressionModel>
         if (expressions.Count == 1) return expressions[0];
         var left = MakeBinOpTree(expressions.Take(expressions.Count - 1).ToList(), op);
         var right = expressions[^1];
-        var span = new Span(left.Span.Filename, left.Span.From, right.Span.To);
+        var span = new Span(left.Span.Filename, left.Span.From, right.Span.To, left.Span.Line);
         return new BinaryOperationExpressionModel(span, left, op, right);
     }
 
@@ -37,7 +37,7 @@ public class ExpressionVisitorNya : MeowBaseVisitorNya<ExpressionModel>
         var remainingExpressions = expressions.Take(expressions.Count - 1).ToList();
         var remainingOps = ops.Take(ops.Count - 1).ToList();
         var left = MakeBinOpTree(remainingExpressions, remainingOps);
-        var span = new Span(left.Span.Filename, left.Span.From, right.Span.To);
+        var span = new Span(left.Span.Filename, left.Span.From, right.Span.To, left.Span.Line);
         return new BinaryOperationExpressionModel(span, left, op, right);
     }
 
@@ -117,7 +117,7 @@ public class ExpressionVisitorNya : MeowBaseVisitorNya<ExpressionModel>
         var expression = Visit(context.pointerDereferenceExpression());
         foreach (var unaryOperator in context._op.Reverse())
         {
-            var span = new Span(expression.Span.Filename, unaryOperator.StartIndex, expression.Span.To);
+            var span = new Span(expression.Span.Filename, unaryOperator.StartIndex, expression.Span.To, expression.Span.Line);
             if (unaryOperator.Text == "&")
             {
                 expression = new PointerReferenceExpressionModel(span, expression);
@@ -137,7 +137,7 @@ public class ExpressionVisitorNya : MeowBaseVisitorNya<ExpressionModel>
         var expression = Visit(context.accessExpression());
         foreach (var op in context._op.Reverse())
         {
-            var span = new Span(expression.Span.Filename, op.StartIndex, expression.Span.To);
+            var span = new Span(expression.Span.Filename, op.StartIndex, expression.Span.To, expression.Span.Line);
             expression = new PointerDereferenceExpressionModel(span, expression);
         }
 
@@ -152,13 +152,13 @@ public class ExpressionVisitorNya : MeowBaseVisitorNya<ExpressionModel>
         {
             if (current.subscript != null) // array access
             {
-                var span = new Span(expression.Span.Filename, expression.Span.From, current.end.StopIndex);
+                var span = new Span(expression.Span.Filename, expression.Span.From, current.end.StopIndex, expression.Span.Line);
                 var indexer = Visit(current.subscript);
                 expression = new ArrayAccessExpressionModel(span, expression, indexer);
             }
             else // struct access
             {
-                var span = new Span(expression.Span.Filename, expression.Span.From, current.name.StopIndex);
+                var span = new Span(expression.Span.Filename, expression.Span.From, current.name.StopIndex, expression.Span.Line);
                 var name = current.name.Text;
                 if (name.Contains('.') || (char.IsDigit(name[0]) && !char.IsDigit(name.TrimStart('0')[0])))
                 {

parser/MeowModelVisitor.cs

@@ -20,6 +20,7 @@ public class MeowModelVisitor<T>
 
     public T Visit(ModelBase m)
     {
+        try {
             switch(m)
             {
 
@@ -84,6 +85,11 @@ public class MeowModelVisitor<T>
                 case VariableDeclarationStatementModel x: return VisitVariableDeclarationStatement(x);
                 case WhileLoopStatementModel x: return VisitWhileLoopStatement(x);
             }
+        } catch(Exception e)
+        {
+            if (e is MeowModelVisitorException) throw;
+            throw new MeowModelVisitorException(m, e);
+        }
         return default;
     }
 
@@ -754,6 +760,7 @@ public class MeowModelVisitor
 {
     public void Visit(ModelBase m)
     {
+        try {
             switch(m)
             {
 
@@ -818,6 +825,9 @@ public class MeowModelVisitor
                 case VariableDeclarationStatementModel x: VisitVariableDeclarationStatement(x); break;
                 case WhileLoopStatementModel x: VisitWhileLoopStatement(x); break;
             }
+        } catch(Exception e) {
+            throw new MeowModelVisitorException(m, e);
+        }
     }
 
     public virtual void VisitArrayAccessExpression(ArrayAccessExpressionModel m)

parser/MeowModelVisitorException.cs

@@ -0,0 +1,11 @@
+namespace meowlang.parser;
+
+public class MeowModelVisitorException : Exception
+{
+    public ModelBase Model { get; }
+
+    public MeowModelVisitorException(ModelBase model, Exception inner) : base($"{inner.Message} on line {model.Span.Line}", inner)
+    {
+        Model = model;
+    }
+}

parser/MeowVisitorException.cs

@@ -6,7 +6,7 @@ public class MeowVisitorException : Exception
 {
     public IToken Token { get; }
 
-    public MeowVisitorException(IToken token, string message) : base(message)
+    public MeowVisitorException(IToken token, string message) : base($"{message} on line {token.Line}")
     {
         Token = token;
     }

parser/Span.cs

@@ -1,3 +1,3 @@
 namespace meowlang.parser;
 
-public record Span(string Filename, int From, int To);
+public record Span(string Filename, int From, int To, int Line);

parser/Utils.cs

@@ -118,7 +118,7 @@ internal static class ParserRuleContextExtensions
 {
     public static Span GetSpan(this ParserRuleContext context)
     {
-        return new Span(context.Start.TokenSource.SourceName, context.Start.StartIndex, context.Stop.StopIndex);
+        return new Span(context.Start.TokenSource.SourceName, context.Start.StartIndex, context.Stop.StopIndex, context.Start.Line);
     }
 }
 
@@ -126,7 +126,7 @@ internal static class TokenExtensions
 {
     public static Span GetSpan(this IToken token)
     {
-        return new Span(token.TokenSource.SourceName, token.StartIndex, token.StopIndex);
+        return new Span(token.TokenSource.SourceName, token.StartIndex, token.StopIndex, token.Line);
     }
 }
 

visitorgenerator/Program.cs

@@ -97,10 +97,15 @@ public class {className}<T>
 
     public T Visit(ModelBase m)
     {{
+        try {{
             switch(m)
             {{
 {string.Join("", arms)}
             }}
+        }} catch(Exception e) {{
+            if (e is MeowModelVisitorException) throw;
+            throw new MeowModelVisitorException(m, e);
+        }}
         return default;
     }}
 {string.Join("", methods)}
@@ -111,10 +116,15 @@ public class {className}
 {{
     public void Visit(ModelBase m)
     {{
+        try {{
             switch(m)
             {{
 {string.Join("", voidArms)}
             }}
+        }} catch(Exception e) {{
+            if (e is MeowModelVisitorException) throw;
+            throw new MeowModelVisitorException(m, e);
+        }}
     }}
 {string.Join("", voidMethods)}
 }}