Initial work on closures. Seems to be working

src/frontend/compiler.nim

@@ -379,13 +379,13 @@ proc getStackPos(self: Compiler, name: IdentExpr, depth: int = self.scopeDepth):
     var found = false
     result = 2
     for variable in self.names:
-        if variable.valueType.kind == Function:
+        if variable.isFunDecl:
             continue
         inc(result)
         if name.name.lexeme == variable.name.name.lexeme:
             if variable.isPrivate and variable.owner != self.currentModule:
                 continue
-            elif variable.depth == depth:
+            else:
                 found = true
                 dec(result)
                 break
@@ -1223,7 +1223,7 @@ proc endScope(self: Compiler) =
     dec(self.scopeDepth)
     var names: seq[Name] = @[]
     for name in self.names:
-        if name.depth > self.scopeDepth and name.valueType.kind notin {Generic, CustomType, Function}:
+        if name.depth > self.scopeDepth and name.valueType.kind notin {Generic, CustomType} and not name.isFunDecl:
             names.add(name)
     if len(names) > 1:
         # If we're popping less than 65535 variables, then
@@ -1435,7 +1435,7 @@ proc endFunctionBeforeReturn(self: Compiler) =
     ## its return instruction
     var popped = 0
     for name in self.names:
-        if name.depth == self.scopeDepth and name.valueType.kind notin {Function, Generic, CustomType}:
+        if name.depth == self.scopeDepth and name.valueType.kind notin {Generic, CustomType} and not name.isFunDecl:
             inc(popped)
     if popped > 1:
         self.emitByte(PopN)
@@ -1849,6 +1849,7 @@ proc compile*(self: Compiler, ast: seq[Declaration], file: string): Chunk =
                                     args: @[]),
                     codePos: 13,  # Jump address is hardcoded
                     name: newIdentExpr(Token(lexeme: "", kind: Identifier)),
+                    isFunDecl: true,
                     line: -1)
     self.names.add(main)
     self.emitByte(LoadFunction)
@@ -1860,7 +1861,7 @@ proc compile*(self: Compiler, ast: seq[Declaration], file: string): Chunk =
     self.emitBytes(0.toTriple())
     while not self.done():
         self.declaration(Declaration(self.step()))
-    self.endFunctionBeforeReturn()
+    self.endScope()
     self.patchReturnAddress(pos)
     self.emitByte(OpCode.Return)
     self.emitByte(0)   # Entry point has no return value