modifiers

src/compiler/Nub.Lang/Frontend/Lexing/Lexer.cs

@@ -5,8 +5,6 @@ public class Lexer
     private static readonly Dictionary<string, Symbol> Keywords = new()
     { 
         ["func"] = Symbol.Func,
-        ["global"] = Symbol.Global,
-        ["extern"] = Symbol.Extern,
         ["import"] = Symbol.Import,
         ["if"] = Symbol.If,
         ["else"] = Symbol.Else,
@@ -18,6 +16,12 @@ public class Lexer
         ["struct"] = Symbol.Struct,
     };
     
+    private static readonly Dictionary<string, Modifier> Modifers = new()
+    { 
+        ["global"] = Modifier.Global,
+        ["extern"] = Modifier.Extern,
+    };
+
     private static readonly Dictionary<char[], Symbol> Chians = new()
     {
         [['=', '=']] = Symbol.Equal,
@@ -84,6 +88,11 @@ public class Lexer
                 return new SymbolToken(keywordSymbol);
             }
             
+            if (Modifers.TryGetValue(buffer, out var modifer))
+            {
+                return new ModifierToken(modifer);
+            }
+            
             if (buffer is "true" or "false")
             {
                 return new LiteralToken(NubPrimitiveType.Bool, buffer);

src/compiler/Nub.Lang/Frontend/Lexing/ModifierToken.cs

@@ -0,0 +1,12 @@
+namespace Nub.Lang.Frontend.Lexing;
+
+public class ModifierToken(Modifier symbol) : Token
+{
+    public Modifier Modifier { get; } = symbol;
+}
+
+public enum Modifier
+{
+    Extern,
+    Global
+}

src/compiler/Nub.Lang/Frontend/Lexing/SymbolToken.cs

@@ -9,8 +9,6 @@ public enum Symbol
 {
     Whitespace,
     Import,
-    Extern,
-    Global,
     Func,
     Return,
     If,

src/compiler/Nub.Lang/Frontend/Parsing/Parser.cs

@@ -35,18 +35,23 @@ public class Parser
 
     private DefinitionNode ParseDefinition()
     {
+        List<Modifier> modifiers = [];
+        
+        while (TryExpectModifier(out var modifier))
+        {
+            modifiers.Add(modifier);
+        }
+        
         var keyword = ExpectSymbol();
         return keyword.Symbol switch
         {
-            Symbol.Func => ParseFuncDefinition(),
-            Symbol.Global => ParseGlobalFuncDefinition(),
-            Symbol.Extern => ParseExternFuncDefinition(),
-            Symbol.Struct => ParseStruct(),
+            Symbol.Func => ParseFuncDefinition(modifiers),
+            Symbol.Struct => ParseStruct(modifiers),
             _ => throw new Exception("Unexpected symbol: " + keyword.Symbol)
         };
     }
 
-    private LocalFuncDefinitionNode ParseFuncDefinition()
+    private DefinitionNode ParseFuncDefinition(List<Modifier> modifiers)
     {
         var name = ExpectIdentifier();
         List<FuncParameter> parameters = [];
@@ -66,64 +71,27 @@ public class Parser
             returnType = ParseType();
         }
 
+        if (modifiers.Remove(Modifier.Extern))
+        {
+            if (modifiers.Count != 0)
+            {
+                throw new Exception($"Modifiers: {string.Join(", ", modifiers)} is not valid for an extern function");
+            }
+            ExpectSymbol(Symbol.Semicolon);
+            return new ExternFuncDefinitionNode(name.Value, parameters, returnType);
+        }
+        
         var body = ParseBlock();
+        var global = modifiers.Remove(Modifier.Global);
         
-        return new LocalFuncDefinitionNode(name.Value, parameters, body, returnType, false);
+        if (modifiers.Count != 0)
+        {
+            throw new Exception($"Modifiers: {string.Join(", ", modifiers)} is not valid for a local function");
+        }
+        return new LocalFuncDefinitionNode(name.Value, parameters, body, returnType, global);
     }
 
-    private LocalFuncDefinitionNode ParseGlobalFuncDefinition()
-    {
-        ExpectSymbol(Symbol.Func);
-        var name = ExpectIdentifier();
-        List<FuncParameter> parameters = [];
-        ExpectSymbol(Symbol.OpenParen);
-        if (!TryExpectSymbol(Symbol.CloseParen))
-        {
-            while (!TryExpectSymbol(Symbol.CloseParen))
-            {
-                parameters.Add(ParseFuncParameter());
-                TryExpectSymbol(Symbol.Comma);
-            }
-        }
-
-        var returnType = Optional<NubType>.Empty();
-        if (TryExpectSymbol(Symbol.Colon))
-        {
-            returnType = ParseType();
-        }
-
-        var body = ParseBlock();
-
-        return new LocalFuncDefinitionNode(name.Value, parameters, body, returnType, true);
-    }
-
-    private ExternFuncDefinitionNode ParseExternFuncDefinition()
-    {
-        ExpectSymbol(Symbol.Func);
-        var name = ExpectIdentifier();
-        List<FuncParameter> parameters = [];
-        ExpectSymbol(Symbol.OpenParen);
-        if (!TryExpectSymbol(Symbol.CloseParen))
-        {
-            while (!TryExpectSymbol(Symbol.CloseParen))
-            {
-                parameters.Add(ParseFuncParameter());
-                TryExpectSymbol(Symbol.Comma);
-            }
-        }
-
-        var returnType = Optional<NubType>.Empty();
-        if (TryExpectSymbol(Symbol.Colon))
-        {
-            returnType = ParseType();
-        }
-
-        ExpectSymbol(Symbol.Semicolon);
-
-        return new ExternFuncDefinitionNode(name.Value, parameters, returnType);
-    }
-
-    private StructDefinitionNode ParseStruct()
+    private StructDefinitionNode ParseStruct(List<Modifier> modifiers)
     {
         var name = ExpectIdentifier().Value;
 
@@ -503,6 +471,19 @@ public class Parser
         return result;
     }
 
+    private bool TryExpectModifier(out Modifier modifier)
+    {
+        if (Peek() is { HasValue: true, Value: ModifierToken modifierToken })
+        {
+            modifier = modifierToken.Modifier;
+            Next();
+            return true;
+        }
+        
+        modifier = default;
+        return false;
+    }
+
     private IdentifierToken ExpectIdentifier()
     {
         var token = ExpectToken();