Support for storing comments about specific variables

Upsilon/Binder/Binder.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Text;
 using Upsilon.BaseTypes;
 using Upsilon.BaseTypes.Number;
 using Upsilon.Parser;
@@ -423,12 +424,23 @@ namespace Upsilon.Binder
                 parameters.Add(vari);
                 innerScope.DefineLocalVariable(vari);
             }
-
+            var commentData = new List<string>();
+            if (e.CommentData != null)
+            {
+                foreach (var comment in e.CommentData)
+                {
+                    commentData.Add(comment);
+                }
+            }
 
             if (!Scope.TryGetVariable(name, !isLocal, out var variable))
             {
-                variable = new FunctionVariableSymbol(name, Type.Function, isLocal, parameters.ToImmutable());
-                ((FunctionVariableSymbol) variable).IsBound = !(func is UnboundFunctionExpression);
+                var functionVariable = new FunctionVariableSymbol(name, Type.Function, isLocal, parameters.ToImmutable())
+                {
+                    CommentValue = commentData.ToArray()
+                };
+                variable = functionVariable;
+                functionVariable.IsBound = !(func is UnboundFunctionExpression);
                 if (isLocal)
                     Scope.DefineLocalVariable(variable);
                 else
@@ -451,6 +463,7 @@ namespace Upsilon.Binder
                 }
             }
 
+
             return new BoundFunctionAssignmentStatement(variable, func, e.Span);
         }
 

Upsilon/Binder/BoundVariableSymbol.cs

@@ -11,6 +11,7 @@ namespace Upsilon.Binder
         }
 
         public VariableSymbol VariableSymbol { get; }
+
         public override BoundKind Kind => BoundKind.BoundVariableSymbol;
         public override BoundNode GetNodeAtPosition(int characterPosition)
         {

Upsilon/Binder/VariableSymbol.cs

@@ -15,6 +15,8 @@ namespace Upsilon.Binder
         public Type Type { get; set; }
         public bool Local { get; }
         public string Name { get; }
+        public string[] CommentValue { get; set; }
+
     }
 
     public class FunctionVariableSymbol : VariableSymbol

Upsilon/Parser/Lexer.cs

@@ -1,4 +1,4 @@
-using System;
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Text;
 using Upsilon.Text;
@@ -26,7 +26,7 @@ namespace Upsilon.Parser
         private char Current => _position >= _text.Length ? '\0' : _text[_position];
         private char Next => _position + 1 >= _text.Length ? '\0' : _text[_position + 1];
 
-
+        private readonly List<string> _activeComments = new List<string>();
         private ImmutableArray<SyntaxToken> Lex()
         {
             var array = ImmutableArray.CreateBuilder<SyntaxToken>();
@@ -35,8 +35,19 @@ namespace Upsilon.Parser
                 var next = LexNext();
                 if (next.Kind != SyntaxKind.WhiteSpace)
                 {
-                    if (next.Kind == SyntaxKind.Comment)
+                    switch (next.Kind)
+                    {
+                        case SyntaxKind.Comment:
+                            _activeComments.Add(next.Value.ToString());
                             continue;
+                        case SyntaxKind.FunctionKeyword:
+                        case SyntaxKind.LocalKeyword:
+                        case SyntaxKind.Identifier:
+                            next.CommentData = _activeComments.ToArray();
+                            break;
+                    }
+
+                    _activeComments.Clear();
                     array.Add(next);
                     if (next.Kind == SyntaxKind.EndOfFile)
                         break;

Upsilon/Parser/Parser.cs

@@ -228,11 +228,17 @@ namespace Upsilon.Parser
         private StatementSyntax ParseFunctionAssignmentStatement()
         {
             SyntaxToken localToken = null;
+            string[] commentData = null;
             if (Current.Kind == SyntaxKind.LocalKeyword)
             {
                 localToken = NextToken();
+                commentData = localToken.CommentData;
             }
             var functionToken   = MatchToken(SyntaxKind.FunctionKeyword);
+            if (commentData == null)
+            {
+                commentData = functionToken.CommentData;
+            }
             var identifier      = MatchToken(SyntaxKind.Identifier);
             var openParenthesis = MatchToken(SyntaxKind.OpenParenthesis);
             var variableBuilder = ImmutableArray.CreateBuilder<IdentifierToken>();
@@ -254,7 +260,10 @@ namespace Upsilon.Parser
             var endToken         = MatchToken(SyntaxKind.EndKeyword);
             var functionExpression = new FunctionExpressionSyntax(functionToken, openParenthesis,
                 variableBuilder.ToImmutable(), closeParenthesis, (BlockStatementSyntax) block, endToken);
-            return new FunctionAssignmentStatementSyntax(localToken, (IdentifierToken) identifier, functionExpression);
+            return new FunctionAssignmentStatementSyntax(localToken, (IdentifierToken) identifier, functionExpression)
+            {
+                CommentData = commentData
+            };
         }
 
         private StatementSyntax ParseExpressionStatement()

Upsilon/Parser/StatementSyntax/FunctionAssignmentStatementSyntax.cs

@@ -18,6 +18,7 @@ namespace Upsilon.Parser
         public SyntaxToken LocalToken    { get; }
         public IdentifierToken Identifier { get; }
         public FunctionExpressionSyntax FunctionExpression { get; }
+        public string[] CommentData { get; set; }
 
         public override SyntaxKind Kind => SyntaxKind.FunctionAssignmentStatement;
         public override IEnumerable<SyntaxNode> ChildNodes()

Upsilon/Parser/SyntaxToken.cs

@@ -14,6 +14,7 @@ namespace Upsilon.Parser
 
         public override SyntaxKind Kind { get; }
         public object Value { get; }
+        public string[] CommentData { get; set; }
 
         public override IEnumerable<SyntaxNode> ChildNodes()
         {