From 64ec7989b477185e6291e20ae7805bec98250e66 Mon Sep 17 00:00:00 2001
From: Victorious3 <vic@nightfall.moe>
Date: Tue, 31 Jan 2023 15:39:12 +0100
Subject: [PATCH] Continue with eliminating inner type variables

---
 .../target/generate/ASTToTargetAST.java         | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/main/java/de/dhbwstuttgart/target/generate/ASTToTargetAST.java b/src/main/java/de/dhbwstuttgart/target/generate/ASTToTargetAST.java
index 14a3c7d5..43e11469 100644
--- a/src/main/java/de/dhbwstuttgart/target/generate/ASTToTargetAST.java
+++ b/src/main/java/de/dhbwstuttgart/target/generate/ASTToTargetAST.java
@@ -568,6 +568,8 @@ public class ASTToTargetAST {
         }
 
         void eliminateInnerTypeVariables(Set<TypePlaceholder> referenced, Set<ResultPair<?, ?>> input) {
+            // Remove type variables that are part of a relation A < B < C where B is not in referenced
+            // Add new pair A < C
             var oldInput = new HashSet<>(input);
             for (var pair : oldInput) {
                 if (pair instanceof PairTPHsmallerTPH ptph && !referenced.contains(ptph.left)) {
@@ -581,6 +583,21 @@ public class ASTToTargetAST {
                     }
                 }
             }
+
+            // Remove lone type variables, A = RefType where A is in no relation X < A or A < X and A is not in referenced
+            oldInput = new HashSet<>(input);
+            outer:
+            for (var pair : oldInput) {
+                if (pair instanceof PairTPHequalRefTypeOrWildcardType ptph) {
+                    if (!referenced.contains(ptph.left)) {
+                        for (var pair2 : oldInput) {
+                            if (pair != pair2 && (pair2.getLeft().equals(ptph.left) || pair2.getRight().equals(ptph.left)))
+                                continue outer;
+                        }
+                        input.remove(pair);
+                    }
+                }
+            }
         }
 
         void eliminateCycles(Set<ResultPair<?, ?>> input) {