1 files changed, 56 insertions, 0 deletions
diff --git a/javaparser-symbol-solver-core/src/main/java/com/github/javaparser/symbolsolver/resolution/typeinference/TypeInferenceCache.java b/javaparser-symbol-solver-core/src/main/java/com/github/javaparser/symbolsolver/resolution/typeinference/TypeInferenceCache.java
new file mode 100644
index 000000000..496aa0001
--- /dev/null
+++ b/javaparser-symbol-solver-core/src/main/java/com/github/javaparser/symbolsolver/resolution/typeinference/TypeInferenceCache.java
@@ -0,0 +1,56 @@
+package com.github.javaparser.symbolsolver.resolution.typeinference;
+
+import com.github.javaparser.ast.expr.LambdaExpr;
+import com.github.javaparser.resolution.types.ResolvedType;
+import com.github.javaparser.symbolsolver.model.resolution.TypeSolver;
+
+import java.util.*;
+
+/**
+ * @author Federico Tomassetti
+ */
+public class TypeInferenceCache {
+
+    private static Map<TypeSolver, IdentityHashMap<LambdaExpr, Map<String, ResolvedType>>> typeForLambdaParameters = new HashMap<>();
+    private static Map<TypeSolver, IdentityHashMap<LambdaExpr, List<InferenceVariable>>> inferenceVariables = new HashMap<>();
+
+    public static void record(TypeSolver typeSolver, LambdaExpr lambdaExpr, String paramName, ResolvedType type) {
+        if (!typeForLambdaParameters.containsKey(typeSolver)) {
+            typeForLambdaParameters.put(typeSolver, new IdentityHashMap<>());
+        }
+        if (!typeForLambdaParameters.get(typeSolver).containsKey(lambdaExpr)) {
+            typeForLambdaParameters.get(typeSolver).put(lambdaExpr, new HashMap<>());
+        }
+        typeForLambdaParameters.get(typeSolver).get(lambdaExpr).put(paramName, type);
+    }
+
+    public static Optional<ResolvedType> retrieve(TypeSolver typeSolver, LambdaExpr lambdaExpr, String paramName) {
+        if (!typeForLambdaParameters.containsKey(typeSolver)) {
+            return Optional.empty();
+        }
+        if (!typeForLambdaParameters.get(typeSolver).containsKey(lambdaExpr)) {
+            return Optional.empty();
+        }
+        if (!typeForLambdaParameters.get(typeSolver).get(lambdaExpr).containsKey(paramName)) {
+            return Optional.empty();
+        }
+        return Optional.of(typeForLambdaParameters.get(typeSolver).get(lambdaExpr).get(paramName));
+    }
+
+    public static void recordInferenceVariables(TypeSolver typeSolver, LambdaExpr lambdaExpr, List<InferenceVariable> _inferenceVariables) {
+        if (!inferenceVariables.containsKey(typeSolver)) {
+            inferenceVariables.put(typeSolver, new IdentityHashMap<>());
+        }
+        inferenceVariables.get(typeSolver).put(lambdaExpr, _inferenceVariables);
+    }
+
+    public static Optional<List<InferenceVariable>> retrieveInferenceVariables(TypeSolver typeSolver, LambdaExpr lambdaExpr) {
+        if (!inferenceVariables.containsKey(typeSolver)) {
+            return Optional.empty();
+        }
+        if (!inferenceVariables.get(typeSolver).containsKey(lambdaExpr)) {
+            return Optional.empty();
+        }
+        return Optional.of(inferenceVariables.get(typeSolver).get(lambdaExpr));
+    }
+}