feat: string interpolation

RobloxCS.Luau/AST/InterpolatedString.cs

@@ -0,0 +1,22 @@
+namespace RobloxCS.Luau
+{
+    public class InterpolatedString : Expression
+    {
+        public List<Expression> Parts { get; }
+
+        public InterpolatedString(List<Expression> parts)
+        {
+            Parts = parts;
+            AddChildren(Parts);
+        }
+
+        public override void Render(LuauWriter luau)
+        {
+            luau.Write('`');
+            foreach (var part in Parts)
+                part.Render(luau);
+
+            luau.Write('`');
+        }
+    }
+}

RobloxCS.Luau/AST/Interpolation.cs

@@ -0,0 +1,22 @@
+namespace RobloxCS.Luau;
+
+/// <summary>
+/// An interpolated section of an <see cref="InterpolatedString"/>
+/// </summary>
+public class Interpolation : Expression
+{
+    public Expression Expression { get; }
+
+    public Interpolation(Expression expression)
+    {
+        Expression = expression;
+        AddChild(Expression);
+    }
+
+    public override void Render(LuauWriter luau)
+    {
+        luau.Write('{');
+        Expression.Render(luau);
+        luau.Write('}');
+    }
+}

RobloxCS.Luau/AST/Literal.cs

@@ -1,17 +1,9 @@
 namespace RobloxCS.Luau
 {
-    public class Literal : Expression
+    public class Literal(string valueText) : Expression
     {
-        public string ValueText { get; }
+        public string ValueText { get; } = valueText;
 
-        public Literal(string valueText)
-        {
-            ValueText = valueText;
-        }
-
-        public override void Render(LuauWriter luau)
-        {
-            luau.Write(ValueText);
-        }
+        public override void Render(LuauWriter luau) => luau.Write(ValueText);
     }
 }

RobloxCS/LuauGenerator.cs

@@ -967,6 +967,18 @@ public override Luau.Node VisitExpressionStatement(ExpressionStatementSyntax nod
             : expressionNode;
     }
 
+    public override Node? VisitInterpolatedStringExpression(InterpolatedStringExpressionSyntax node)
+    {
+        var parts = node.Contents.Select(Visit<Luau.Expression>).ToList();
+        return new Luau.InterpolatedString(parts);
+    }
+
+    public override Luau.Literal VisitInterpolatedStringText(InterpolatedStringTextSyntax node) =>
+        new(node.TextToken.Text);
+
+    public override Luau.Interpolation VisitInterpolation(InterpolationSyntax node) =>
+        new(Visit<Luau.Expression>(node.Expression));
+
     public override Luau.Literal VisitLiteralExpression(LiteralExpressionSyntax node)
     {
         var valueText = "";