Merge branch 'master' of https://git.scc.kit.edu/pse-typinferenz/typicalc

src/main/java/edu/kit/typicalc/model/Tree.java

@@ -1,9 +1,6 @@
 package edu.kit.typicalc.model;
 
-import edu.kit.typicalc.model.step.InferenceStep;
+import edu.kit.typicalc.model.step.*;
-import edu.kit.typicalc.model.step.StepFactory;
-import edu.kit.typicalc.model.step.StepFactoryDefault;
-import edu.kit.typicalc.model.step.StepFactoryWithLet;
 import edu.kit.typicalc.model.term.AbsTerm;
 import edu.kit.typicalc.model.term.AppTerm;
 import edu.kit.typicalc.model.term.ConstTerm;
@@ -133,7 +130,43 @@ public class Tree implements TermVisitorTree {
 
     @Override
     public InferenceStep visit(LetTerm letTerm, Map<VarTerm, TypeAbstraction> typeAssumptions, Type conclusionType) {
-        return null; // TODO
+        TypeInfererLet typeInfererLet = new TypeInfererLet(
+                letTerm.getVariableDefinition(), typeAssumptions, typeVarFactory);
+
+        Type premiseType = typeVarFactory.nextTypeVariable();
+        Constraint newConstraint = new Constraint(conclusionType, premiseType);
+        InferenceStep premise;
+
+        if (typeInfererLet.getType().isPresent()) {
+            Map<VarTerm, TypeAbstraction> extendedTypeAssumptions = new HashMap<>(typeAssumptions);
+            extendedTypeAssumptions.replaceAll((key, value) -> {
+                Type newType = value.getInnerType();
+                for (Substitution substitution : typeInfererLet.getMGU().get()) {
+                    if (value.getQuantifiedVariables().contains(substitution.getVariable())) {
+                        continue;
+                    }
+                    newType = newType.substitute(substitution);
+                }
+                return new TypeAbstraction(newType, value.getQuantifiedVariables());
+            });
+
+            List<TypeVariable> variablesToQuantify = new ArrayList<>();
+            // TODO variablesToQuantify berechnen
+
+            TypeAbstraction newTypeAbstraction = new TypeAbstraction(typeInfererLet.getType().get(),
+                    variablesToQuantify);
+            extendedTypeAssumptions.put(letTerm.getVariable(), newTypeAbstraction);
+
+            premise = letTerm.getInner().accept(this, extendedTypeAssumptions, premiseType);
+
+            constraints.add(newConstraint);
+            constraints.addAll(typeInfererLet.getLetConstraints());
+        } else {
+            premise = new EmptyStep();
+        }
+
+        Conclusion conclusion = new Conclusion(typeAssumptions, letTerm, conclusionType);
+        return stepFactory.createLetStep(conclusion, newConstraint, premise, typeInfererLet);
     }
 
     @Override

src/main/java/edu/kit/typicalc/model/step/EmptyStep.java

@@ -0,0 +1,32 @@
+package edu.kit.typicalc.model.step;
+
+import edu.kit.typicalc.model.Conclusion;
+import edu.kit.typicalc.model.Constraint;
+
+/**
+ * Empty Steps are used if the sub-inference started when creating a let step failed and the second premise of
+ * this let step therefore cannot be calculated.
+ */
+public class EmptyStep extends InferenceStep {
+    /**
+     * Initializes a new EmptyStep.
+     */
+    public EmptyStep() {
+        super(null, null); // TODO
+    }
+
+    @Override
+    public Conclusion getConclusion() {
+        throw new IllegalStateException("getConclusion() should never be called on an empty step");
+    }
+
+    @Override
+    public Constraint getConstraint() {
+        throw new IllegalStateException("getConstraint() should never be called on an empty step");
+    }
+
+    @Override
+    public void accept(StepVisitor stepVisitor) {
+        stepVisitor.visit(this);
+    }
+}

src/main/java/edu/kit/typicalc/model/step/StepVisitor.java

@@ -47,8 +47,9 @@ public interface StepVisitor {
      */
     void visit(LetStepDefault letD);
 
-
+    /**
-
+     * Visits an empty step
-
+     * @param empty the empty step to visit
-
+     */
+    void visit(EmptyStep empty);
 }

src/main/java/edu/kit/typicalc/view/content/typeinferencecontent/LatexCreator.java

@@ -179,6 +179,11 @@ public class LatexCreator implements StepVisitor, TypeVisitor {
         // todo implement
     }
 
+    @Override
+    public void visit(EmptyStep empty) {
+        // TODO
+    }
+
     @Override
     public void visit(NamedType named) {
         visitorBuffer = TEXTTT + CURLY_LEFT + named.getName() + CURLY_RIGHT;