parser // tightened up Syntax/Expr/Type syntax

src/MiniZinc.Parser/Parser.cs

@@ -1925,7 +1925,7 @@ ident.Kind is TokenKind.GENERIC_SEQUENCE
     internal bool ParseArrayType([NotNullWhen(true)] out ArrayTypeSyntax? arr)
     {
         arr = default;
-        var dims = new List<SyntaxNode>();
+        var dims = new List<TypeSyntax>();
 
         if (!Expect(TokenKind.ARRAY, out var start))
             return false;

src/MiniZinc.Parser/Syntax/IndexAndNode.cs

@@ -2,10 +2,10 @@
 
 public sealed class IndexAndNode : ExpressionSyntax
 {
-    public readonly SyntaxNode Index;
-    public readonly SyntaxNode Value;
+    public readonly ExpressionSyntax Index;
+    public readonly ExpressionSyntax Value;
 
-    public IndexAndNode(SyntaxNode index, SyntaxNode value)
+    public IndexAndNode(ExpressionSyntax index, ExpressionSyntax value)
         : base(index.Start)
     {
         Index = index;

src/MiniZinc.Parser/Syntax/LetSyntax.cs

@@ -2,7 +2,7 @@
 
 public sealed class LetSyntax : ExpressionSyntax
 {
-    public LetSyntax(in Token start, List<ILetLocalSyntax>? locals, SyntaxNode body)
+    public LetSyntax(in Token start, List<ILetLocalSyntax>? locals, ExpressionSyntax body)
         : base(start)
     {
         Locals = locals;
@@ -11,5 +11,5 @@ public LetSyntax(in Token start, List<ILetLocalSyntax>? locals, SyntaxNode body)
 
     public List<ILetLocalSyntax>? Locals { get; }
 
-    public SyntaxNode Body { get; }
+    public ExpressionSyntax Body { get; }
 }

src/MiniZinc.Parser/Syntax/SetLiteralSyntax.cs

@@ -5,5 +5,5 @@ public sealed class SetLiteralSyntax : ExpressionSyntax
     public SetLiteralSyntax(in Token start)
         : base(start) { }
 
-    public List<SyntaxNode> Elements { get; } = new();
+    public List<ExpressionSyntax> Elements { get; } = new();
 }

src/MiniZinc.Parser/Syntax/SyntaxExtensions.cs

@@ -2,6 +2,17 @@
 
 public static class SyntaxExtensions
 {
+    /// <summary>
+    /// Write this node as a minizinc string
+    /// </summary>
+    public static string Write(this SyntaxNode node, WriteOptions? options = null)
+    {
+        var writer = new Writer(options);
+        writer.WriteSyntax(node);
+        var mzn = writer.ToString();
+        return mzn;
+    }
+
     /// <summary>
     /// Create a deep clone of this syntax node
     /// </summary>

src/MiniZinc.Parser/Syntax/SyntaxNode.cs

@@ -14,18 +14,7 @@ protected SyntaxNode(in Token start)
         Start = start;
     }
 
-    public string SourceText => Write(WriteOptions.Minimal);
-
-    /// <summary>
-    /// Write this node as a minizinc string
-    /// </summary>
-    public string Write(WriteOptions? options = null)
-    {
-        var writer = new Writer(options);
-        writer.WriteSyntax(this);
-        var mzn = writer.ToString();
-        return mzn;
-    }
+    public string SourceText => this.Write(WriteOptions.Minimal);
 
     public override bool Equals(object? obj)
     {

src/MiniZinc.Parser/Syntax/TupleAccessSyntax.cs

@@ -2,7 +2,7 @@
 
 public sealed class TupleAccessSyntax : ExpressionSyntax
 {
-    public readonly SyntaxNode Expr;
+    public readonly ExpressionSyntax Expr;
 
     public readonly Token Field;
 

src/MiniZinc.Parser/Syntax/TypeInstSyntax.cs

@@ -63,13 +63,13 @@ public TupleTypeSyntax(in Token Start)
 
 public sealed class ExprType : TypeSyntax
 {
-    public ExprType(in Token Start, SyntaxNode Expr)
+    public ExprType(in Token Start, ExpressionSyntax Expr)
         : base(Start)
     {
         this.Expr = Expr;
     }
 
-    public SyntaxNode Expr { get; init; }
+    public ExpressionSyntax Expr { get; init; }
 }
 
 public sealed class ArrayTypeSyntax : TypeSyntax
@@ -79,7 +79,7 @@ public ArrayTypeSyntax(in Token Start)
 
     public required TypeSyntax Items { get; set; }
 
-    public required List<SyntaxNode> Dimensions { get; set; }
+    public required List<TypeSyntax> Dimensions { get; set; }
 
     public int N => Dimensions.Count;
 }

src/MiniZinc.Parser/Syntax/UnaryOperatorSyntax.cs

@@ -4,9 +4,9 @@ public sealed class UnaryOperatorSyntax : ExpressionSyntax
 {
     public Operator Operator { get; }
 
-    public SyntaxNode Expr { get; }
+    public ExpressionSyntax Expr { get; }
 
-    public UnaryOperatorSyntax(in Token start, Operator op, SyntaxNode expr)
+    public UnaryOperatorSyntax(in Token start, Operator op, ExpressionSyntax expr)
         : base(start)
     {
         Operator = op;