implement "it" as closure self reference & lua robustness

de.peeeq.wurstscript/src/main/antlr/de/peeeq/wurstscript/antlr/Wurst.g4

@@ -340,7 +340,7 @@ exprMemberVar:
 
 
 exprVarAccess:
-				 varname=ID indexes?
+				 varname=(ID|IT) indexes?
 			 ;
 
 
@@ -375,7 +375,7 @@ exprPrimary:
 	  | exprClosure
 	  | exprStatementsBlock
 	  | exprDestroy
-      | varname=ID indexes?
+      | varname=(ID|IT) indexes?
       | atom=(INT
       | REAL
 	  | STRING

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/attributes/AttrClosureCapturedVariables.java

@@ -4,6 +4,7 @@
 import com.google.common.collect.ImmutableMultimap.Builder;
 import de.peeeq.wurstscript.ast.*;
 import de.peeeq.wurstscript.attributes.names.NameLink;
+import de.peeeq.wurstscript.attributes.names.OtherLink;
 import de.peeeq.wurstscript.types.WurstTypeArray;
 
 import java.util.Map.Entry;
@@ -33,6 +34,10 @@ private static void collect(Builder<Element, VarDef> result, ExprClosure closure
         if (e instanceof NameRef) {
             NameRef nr = (NameRef) e;
             NameLink def = nr.attrNameLink();
+            if (def instanceof OtherLink) {
+                // Synthetic links (e.g. implicit closure-self) are not captured locals.
+                return;
+            }
 
             if (def != null && isLocalVariable(def.getDef())) {
                 VarDef v = (VarDef) def.getDef();

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/attributes/AttrConstantValue.java

@@ -3,6 +3,7 @@
 import de.peeeq.wurstscript.WurstOperator;
 import de.peeeq.wurstscript.ast.*;
 import de.peeeq.wurstscript.attributes.names.NameLink;
+import de.peeeq.wurstscript.attributes.names.OtherLink;
 import de.peeeq.wurstscript.intermediatelang.ILconst;
 import de.peeeq.wurstscript.intermediatelang.ILconstInt;
 
@@ -31,6 +32,9 @@ public static ILconst calculate(ExprIntVal e) {
 
     public static ILconst calculate(ExprVarAccess e) {
         NameLink v = e.attrNameLink();
+        if (v instanceof OtherLink) {
+            throw new ConstantValueCalculationException(e.toString());
+        }
         if (v != null && v.getDef() instanceof GlobalVarDef) {
             GlobalVarDef g = (GlobalVarDef) v.getDef();
             if (g.attrIsConstant() && g.getInitialExpr() instanceof Expr) {

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/attributes/AttrExprType.java

@@ -5,6 +5,7 @@
 import de.peeeq.wurstscript.ast.*;
 import de.peeeq.wurstscript.attributes.names.FuncLink;
 import de.peeeq.wurstscript.attributes.names.NameLink;
+import de.peeeq.wurstscript.attributes.names.OtherLink;
 import de.peeeq.wurstscript.types.*;
 import de.peeeq.wurstscript.utils.Utils;
 import org.eclipse.jdt.annotation.Nullable;
@@ -68,13 +69,13 @@ public static WurstType calculate(ExprVarAccess term) {
 
             return WurstTypeUnknown.instance();
         }
-        if (varDef.getDef() instanceof VarDef) {
+        if (!(varDef instanceof OtherLink) && varDef.getDef() instanceof VarDef) {
             if (Utils.getParentVarDef(Optional.of(term)) == Optional.of((VarDef) varDef.getDef())) {
                 term.addError("Recursive variable definition is not allowed.");
                 return WurstTypeUnknown.instance();
             }
         }
-        if (varDef.getDef() instanceof FunctionDefinition) {
+        if (!(varDef instanceof OtherLink) && varDef.getDef() instanceof FunctionDefinition) {
             term.addError("Missing parantheses for function call");
         }
         return varDef.getTyp();
@@ -388,10 +389,10 @@ public static WurstType calculate(ExprMemberVarDot term) {
         if (varDef == null) {
             return WurstTypeUnknown.instance();
         }
-        if (varDef.getDef() instanceof FunctionDefinition) {
+        if (!(varDef instanceof OtherLink) && varDef.getDef() instanceof FunctionDefinition) {
             term.addError("Missing parantheses for function call");
         }
-        if (varDef.getDef().attrIsStatic() && !term.getLeft().attrTyp().isStaticRef()) {
+        if (!(varDef instanceof OtherLink) && varDef.getDef().attrIsStatic() && !term.getLeft().attrTyp().isStaticRef()) {
             term.addError("Cannot access static variable " + term.getVarName() + " via a dynamic reference.");
         }
         return varDef.getTyp(); // TODO .setTypeArgs(term.getLeft().attrTyp().getTypeArgBinding());
@@ -403,7 +404,7 @@ public static WurstType calculate(ExprMemberArrayVarDot term) {
         if (varDef == null) {
             return WurstTypeUnknown.instance();
         }
-        if (varDef.getDef().attrIsStatic() && !term.getLeft().attrTyp().isStaticRef()) {
+        if (!(varDef instanceof OtherLink) && varDef.getDef().attrIsStatic() && !term.getLeft().attrTyp().isStaticRef()) {
             term.addError("Cannot access static array variable " + term.getVarName() + " via a dynamic reference.");
         }
         WurstType typ = varDef.getTyp();

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/attributes/AttrImplicitParameter.java

@@ -3,6 +3,7 @@
 import de.peeeq.wurstscript.ast.*;
 import de.peeeq.wurstscript.attributes.names.FuncLink;
 import de.peeeq.wurstscript.attributes.names.NameLink;
+import de.peeeq.wurstscript.attributes.names.OtherLink;
 import de.peeeq.wurstscript.types.WurstType;
 import org.eclipse.jdt.annotation.Nullable;
 
@@ -108,6 +109,9 @@ static OptExpr getFunctionCallImplicitParameter(FunctionCall e, FuncLink calledF
 
     private static OptExpr getImplicitParamterCaseNormalVar(NameRef e) {
         NameLink def = e.attrNameLink();
+        if (def instanceof OtherLink) {
+            return Ast.NoExpr();
+        }
         if (def != null && def.getDef() instanceof VarDef) {
             VarDef varDef = (VarDef) def.getDef();
             if (varDef.attrIsDynamicClassMember()) {

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/attributes/AttrNameDef.java

@@ -3,7 +3,11 @@
 import de.peeeq.wurstscript.ast.*;
 import de.peeeq.wurstscript.attributes.names.FuncLink;
 import de.peeeq.wurstscript.attributes.names.NameLink;
+import de.peeeq.wurstscript.attributes.names.OtherLink;
+import de.peeeq.wurstscript.attributes.names.Visibility;
 import de.peeeq.wurstscript.types.WurstType;
+import de.peeeq.wurstscript.types.WurstTypeClassOrInterface;
+import de.peeeq.wurstscript.types.WurstTypeUnknown;
 import de.peeeq.wurstscript.types.WurstTypeEnum;
 import de.peeeq.wurstscript.types.WurstTypeModule;
 import org.eclipse.jdt.annotation.Nullable;
@@ -74,8 +78,52 @@ public static NameLink calculate(ExprMemberVar term) {
 
     protected static NameLink searchNameInScope(String varName, NameRef node) {
         boolean showErrors = !varName.startsWith("gg_");
-        NameLink result = node.lookupVar(varName, showErrors);
-        return result;
+        if (!"it".equals(varName)) {
+            return node.lookupVar(varName, showErrors);
+        }
+
+        // Normal lexical lookup wins, so user-defined names can shadow implicit closure-self.
+        NameLink result = node.lookupVar(varName, false);
+        if (result != null) {
+            return result;
+        }
+
+        NameLink implicitClosureSelf = lookupImplicitClosureSelf(node, showErrors);
+        if (implicitClosureSelf != null) {
+            return implicitClosureSelf;
+        }
+        if (node.attrNearestExprClosure() != null) {
+            // keep diagnostics focused on closure typing instead of "unknown variable it"
+            return null;
+        }
+
+        if (!showErrors) {
+            return null;
+        }
+
+        // Fallback to default diagnostics when no implicit closure-self is available.
+        return node.lookupVar(varName, true);
+    }
+
+    private static @Nullable NameLink lookupImplicitClosureSelf(NameRef node, boolean showErrors) {
+        ExprClosure closure = node.attrNearestExprClosure();
+        if (closure == null) {
+            return null;
+        }
+        WurstType expectedTyp = closure.attrExpectedTypAfterOverloading();
+        if (!(expectedTyp instanceof WurstTypeClassOrInterface)) {
+            if (showErrors && (expectedTyp instanceof WurstTypeUnknown)) {
+                node.addError("Cannot use implicit closure self 'it' because the closure target type is unknown.");
+            }
+            return null;
+        }
+
+        return new OtherLink(Visibility.LOCAL, "it", expectedTyp) {
+            @Override
+            public de.peeeq.wurstscript.jassIm.ImExpr translate(NameRef e, de.peeeq.wurstscript.translation.imtranslation.ImTranslator t, de.peeeq.wurstscript.jassIm.ImFunction f) {
+                return de.peeeq.wurstscript.jassIm.JassIm.ImVarAccess(t.getThisVar(closure));
+            }
+        };
     }
 
     private static boolean isWriteAccess(final NameRef node) {
@@ -110,7 +158,7 @@ private static boolean isWriteAccess(final NameRef node) {
 
     public static @Nullable NameDef tryGetNameDef(NameRef e) {
         NameLink link = e.attrNameLink();
-        if (link == null) {
+        if (link == null || link instanceof OtherLink) {
             return null;
         }
         return link.getDef();
@@ -139,6 +187,9 @@ private static boolean isWriteAccess(final NameRef node) {
 
     public static NameDef calculateDef(NameRef nameRef) {
         NameLink l = nameRef.attrNameLink();
+        if (l instanceof OtherLink) {
+            return null;
+        }
         return l == null ? null : l.getDef();
     }
 }

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/attributes/DescriptionHtml.java

@@ -4,6 +4,7 @@
 import de.peeeq.wurstscript.ast.*;
 import de.peeeq.wurstscript.attributes.names.FuncLink;
 import de.peeeq.wurstscript.attributes.names.NameLink;
+import de.peeeq.wurstscript.attributes.names.OtherLink;
 import de.peeeq.wurstscript.types.WurstType;
 import de.peeeq.wurstscript.utils.Utils;
 import org.eclipse.jdt.annotation.Nullable;
@@ -160,6 +161,9 @@ public static String description(NameRef nr) {
         if (nameDef == null) {
             return nr.getVarName() + " is not defined yet.";
         }
+        if (nameDef instanceof OtherLink) {
+            return nr.getVarName() + " has type " + htmlType(nameDef.getTyp());
+        }
         return nameDef.getDef().descriptionHtml();
     }
 

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/attributes/ReadVariables.java

@@ -33,7 +33,7 @@ private static ImmutableList<NameDef> generic(Element e) {
     }
 
     public static ImmutableList<NameDef> calculate(ExprVarAccess e) {
-        if (e.attrNameLink() != null) {
+        if (e.attrNameLink() != null && e.attrNameDef() != null) {
             return ImmutableList.of(e.attrNameDef());
         } else {
             return ImmutableList.emptyList();
@@ -42,7 +42,7 @@ public static ImmutableList<NameDef> calculate(ExprVarAccess e) {
 
     public static ImmutableList<NameDef> calculate(ExprVarArrayAccess e) {
         ImmutableList<NameDef> r = ImmutableList.emptyList();
-        if (e.attrNameLink() != null) {
+        if (e.attrNameLink() != null && e.attrNameDef() != null) {
             r = ImmutableList.of(e.attrNameDef());
         }
         r = r.cons(generic(e.getIndexes()));
@@ -51,7 +51,7 @@ public static ImmutableList<NameDef> calculate(ExprVarArrayAccess e) {
 
     public static ImmutableList<NameDef> calculate(ExprMemberArrayVar e) {
         ImmutableList<NameDef> r = ImmutableList.emptyList();
-        if (e.attrNameLink() != null) {
+        if (e.attrNameLink() != null && e.attrNameDef() != null) {
             r = ImmutableList.of(e.attrNameDef());
         }
         r = r.cons(e.getLeft().attrReadVariables());

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/attributes/UsedGlobalVariables.java

@@ -5,6 +5,7 @@
 import de.peeeq.wurstscript.ast.*;
 import de.peeeq.wurstscript.attributes.names.FuncLink;
 import de.peeeq.wurstscript.attributes.names.NameLink;
+import de.peeeq.wurstscript.attributes.names.OtherLink;
 import de.peeeq.wurstscript.types.WurstType;
 import de.peeeq.wurstscript.types.WurstTypeClass;
 
@@ -36,7 +37,7 @@ public static ImmutableList<VarDef> getUsedGlobals(ExprOrStatements e) {
         } else if (e instanceof NameRef) {
             NameRef nameRef = (NameRef) e;
             NameLink def = nameRef.attrNameLink();
-            if (def.getDef() instanceof GlobalVarDef) {
+            if (def != null && !(def instanceof OtherLink) && def.getDef() instanceof GlobalVarDef) {
                 GlobalVarDef varDef = (GlobalVarDef) def.getDef();
                 result.add(varDef);
             }
@@ -103,7 +104,7 @@ private static void collectReadGlobals(Element e, Builder<VarDef> result) {
                 // write access
             } else {
                 NameLink def = nameRef.attrNameLink();
-                if (def.getDef() instanceof GlobalVarDef) {
+                if (def != null && !(def instanceof OtherLink) && def.getDef() instanceof GlobalVarDef) {
                     GlobalVarDef varDef = (GlobalVarDef) def.getDef();
                     result.add(varDef);
                 }

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/attributes/UsedPackages.java

@@ -8,6 +8,7 @@
 import de.peeeq.wurstscript.ast.VarDef;
 import de.peeeq.wurstscript.ast.WPackage;
 import de.peeeq.wurstscript.attributes.names.NameLink;
+import de.peeeq.wurstscript.attributes.names.OtherLink;
 
 public class UsedPackages {
 
@@ -34,7 +35,7 @@ private static void processChildren(Element e,
     public static ImmutableCollection<WPackage> usedPackages(NameRef e) {
         ImmutableSet.Builder<WPackage> result = ImmutableSet.builder();
         NameLink def = e.attrNameLink();
-        if (def.getDef() instanceof VarDef) {
+        if (def != null && !(def instanceof OtherLink) && def.getDef() instanceof VarDef) {
             if (def.getDef().attrNearestPackage() instanceof WPackage) {
                 result.add((WPackage) e.attrNearestPackage());
             }

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/translation/imtranslation/ExprTranslation.java

@@ -247,6 +247,9 @@ public static ImExpr translateIntern(NameRef e, ImTranslator t, ImFunction f) {
 
     private static ImExpr translateNameDef(NameRef e, ImTranslator t, ImFunction f) throws CompileError {
         NameLink link = e.attrNameLink();
+        if (link instanceof OtherLink) {
+            return ((OtherLink) link).translate(e, t, f);
+        }
         NameDef decl = link == null ? null : link.getDef();
         if (decl == null) {
             // should only happen with gg_ variables
@@ -303,9 +306,6 @@ private static ImExpr translateNameDef(NameRef e, ImTranslator t, ImFunction f)
             EnumMember enumMember = (EnumMember) decl;
             int id = t.getEnumMemberId(enumMember);
             return ImIntVal(id);
-        } else if (link instanceof OtherLink) {
-            OtherLink otherLink = (OtherLink) link;
-            return otherLink.translate(e, t, f);
         } else {
             throw new CompileError(e.getSource(), "Cannot translate reference to " + Utils.printElement(decl));
         }

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/translation/lua/translation/LuaTranslator.java

@@ -775,9 +775,12 @@ private boolean rewriteTypeCastingCompatFunction(ImFunction f, LuaFunction lf) {
         if (f.getParameters().isEmpty()) {
             return false;
         }
-        String tcFunc = f.getName();
-        ImVar p = f.getParameters().get(0);
-        LuaExpr arg = LuaAst.LuaExprVarAccess(luaVar.getFor(p));
+        String tcFunc = getTypeCastingFunctionName(f);
+        if (tcFunc == null) {
+            return false;
+        }
+        ImVar firstParam = f.getParameters().get(0);
+        LuaExpr arg = LuaAst.LuaExprVarAccess(luaVar.getFor(firstParam));
 
         if ("stringToIndex".equals(tcFunc)) {
             lf.getBody().clear();
@@ -805,17 +808,6 @@ private boolean rewriteTypeCastingCompatFunction(ImFunction f, LuaFunction lf) {
             lf.getBody().add(LuaAst.LuaReturn(LuaAst.LuaExprFunctionCall(fromIndexFunction, LuaAst.LuaExprlist(arg))));
             return true;
         }
-        // Final fallback for transformed/copied function names that may lose trace info:
-        if (tcFunc.endsWith("ToIndex")) {
-            lf.getBody().clear();
-            lf.getBody().add(LuaAst.LuaReturn(LuaAst.LuaExprFunctionCall(toIndexFunction, LuaAst.LuaExprlist(arg))));
-            return true;
-        }
-        if (tcFunc.endsWith("FromIndex")) {
-            lf.getBody().clear();
-            lf.getBody().add(LuaAst.LuaReturn(LuaAst.LuaExprFunctionCall(fromIndexFunction, LuaAst.LuaExprlist(arg))));
-            return true;
-        }
         return false;
     }
 
@@ -1100,13 +1092,6 @@ public String getTypeCastingFunctionName(ImFunction f) {
                 return fd.getName();
             }
         }
-        // Fallback: transformed/copied IM functions may lose package trace metadata.
-        // Keep Lua behavior stable by routing canonical *ToIndex/*FromIndex names anyway.
-        String name = f.getName();
-        if ("stringToIndex".equals(name) || "stringFromIndex".equals(name)
-            || name.endsWith("ToIndex") || name.endsWith("FromIndex")) {
-            return name;
-        }
         return null;
     }
 }

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/validation/ValidateLocalUsage.java

@@ -2,6 +2,7 @@
 
 import de.peeeq.wurstscript.ast.*;
 import de.peeeq.wurstscript.attributes.names.NameLink;
+import de.peeeq.wurstscript.attributes.names.OtherLink;
 
 import java.util.Collection;
 import java.util.HashSet;
@@ -42,7 +43,7 @@ public void visit(StmtSet set) {
                 LExpr updatedExpr = set.getUpdatedExpr();
                 if (updatedExpr != null) {
                     NameLink nameLink = updatedExpr.attrNameLink();
-                    if (nameLink != null) {
+                    if (nameLink != null && !(nameLink instanceof OtherLink)) {
                         locals.remove(nameLink.getDef());
                     }