1 files changed, 99 insertions, 0 deletions
diff --git a/src/main/java/org/javacs/Ptr.java b/src/main/java/org/javacs/Ptr.java
new file mode 100644
index 0000000..71520a3
--- /dev/null
+++ b/src/main/java/org/javacs/Ptr.java
@@ -0,0 +1,99 @@
+package org.javacs;
+
+import com.sun.source.tree.ClassTree;
+import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.VariableTree;
+import com.sun.source.util.TreePath;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.StringJoiner;
+import java.util.logging.Logger;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ExecutableElement;
+import javax.lang.model.element.PackageElement;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.element.VariableElement;
+
+/** Ptr is a serialized TreePath, suitable for storing in Index and remember across compiler invocations */
+public class Ptr {
+    private final String path;
+
+    public Ptr(TreePath path) {
+        var packageName = path.getCompilationUnit().getPackageName();
+        var rev = new ArrayList<CharSequence>();
+        while (path != null) {
+            var part = path.getLeaf();
+            if (part instanceof ClassTree) {
+                var cls = (ClassTree) part;
+                rev.add(cls.getSimpleName());
+            } else if (part instanceof MethodTree) {
+                var method = (MethodTree) part;
+                // TODO overloads
+                rev.add(method.getName());
+            } else if (part instanceof VariableTree) {
+                var variable = (VariableTree) part;
+                rev.add(variable.getName());
+            }
+            path = path.getParentPath();
+        }
+        if (packageName != null) rev.add(packageName.toString());
+        var name = reverseAndJoin(rev, ".");
+        if (!name.matches("(\\w+\\.)*(\\w+|<init>)")) LOG.warning(String.format("`%s` doesn't look like a name", name));
+        this.path = name;
+    }
+
+    public Ptr(Element e) {
+        var rev = new ArrayList<CharSequence>();
+        while (e != null) {
+            if (e instanceof PackageElement) {
+                var pkg = (PackageElement) e;
+                if (!pkg.isUnnamed()) rev.add(pkg.getQualifiedName());
+            } else if (e instanceof TypeElement) {
+                var type = (TypeElement) e;
+                rev.add(type.getSimpleName());
+            } else if (e instanceof ExecutableElement) {
+                var method = (ExecutableElement) e;
+                // TODO overloads
+                rev.add(method.getSimpleName());
+            } else if (e instanceof VariableElement) {
+                var field = (VariableElement) e;
+                rev.add(field.getSimpleName());
+            }
+            e = e.getEnclosingElement();
+        }
+        var name = reverseAndJoin(rev, ".");
+        if (!name.matches("(\\w+\\.)*(\\w+|<init>)")) LOG.warning(String.format("`%s` doesn't look like a name", name));
+        this.path = name;
+    }
+
+    private static String reverseAndJoin(List<CharSequence> parts, String sep) {
+        var join = new StringJoiner(sep);
+        for (var i = parts.size() - 1; i >= 0; i--) {
+            join.add(parts.get(i));
+        }
+        return join.toString();
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (!(other instanceof Ptr)) return false;
+        var that = (Ptr) other;
+        return this.path.equals(that.path);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(path);
+    }
+
+    public boolean inPackage(String packageName) {
+        return path.startsWith(packageName);
+    }
+
+    public boolean inClass(String qualifiedName) {
+        return path.startsWith(qualifiedName);
+    }
+
+    private static final Logger LOG = Logger.getLogger("main");
+}