Make Ptr more precies

1 files changed, 201 insertions, 30 deletions

diff --git a/src/main/java/org/javacs/Ptr.java b/src/main/java/org/javacs/Ptr.java
index 71d1b6c..2deff56 100644
--- a/src/main/java/org/javacs/Ptr.java
+++ b/src/main/java/org/javacs/Ptr.java
@@ -1,57 +1,124 @@
 package org.javacs;
 
+import com.sun.source.tree.*;
+import com.sun.source.util.TreePath;
+import com.sun.source.util.TreeScanner;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
+import java.util.Optional;
 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;
+import javax.lang.model.element.*;
+import javax.lang.model.type.*;
 
 /** Ptr is a reference to a named element, that can be serialized into a String. */
 public class Ptr {
-    private final String path;
+    private final String packageName, className;
+    private final Optional<String> memberName;
+    private final Optional<List<String>> erasedParameterTypes;
 
-    public Ptr(String path) {
-        this.path = path;
+    public static Ptr toClass(String packageName, String className) {
+        return new Ptr(packageName, className);
     }
 
-    public static boolean canPoint(Element e) {
-        var inLeaf = true;
-        for (; e != null; e = e.getEnclosingElement()) {
-            var isLeaf = e instanceof ExecutableElement || e instanceof VariableElement;
-            if (inLeaf && !isLeaf) inLeaf = false;
-            if (!inLeaf && isLeaf) return false;
+    private Ptr(String packageName, String className) {
+        this.packageName = packageName;
+        this.className = className;
+        this.memberName = Optional.empty();
+        this.erasedParameterTypes = Optional.empty();
+    }
+
+    public Ptr(String path) {
+        // Split my.pkg/Class#member into my.pkg and Class#member
+        var slash = path.indexOf('/');
+        if (slash == -1) {
+            this.packageName = "";
+        } else {
+            this.packageName = path.substring(0, slash);
+            path = path.substring(slash + 1);
         }
-        return true;
+
+        // Split Class#member into Class and member
+        var hash = path.indexOf('#');
+        if (hash == -1) {
+            this.className = path;
+            this.memberName = Optional.empty();
+            this.erasedParameterTypes = Optional.empty();
+            return;
+        }
+        this.className = path.substring(0, hash);
+        path = path.substring(hash + 1);
+
+        // Split method(int,java.lang.String) into method and int,java.lang.String
+        var paren = path.indexOf('(');
+        if (paren == -1) {
+            this.memberName = Optional.of(path);
+            this.erasedParameterTypes = Optional.empty();
+            return;
+        }
+        this.memberName = Optional.of(path.substring(0, paren));
+        path = path.substring(paren + 1, path.length() - 1);
+
+        // Split int,java.lang.String
+        if (path.isEmpty()) {
+            this.erasedParameterTypes = Optional.of(List.of());
+            return;
+        }
+        var params = path.split(",");
+        this.erasedParameterTypes = Optional.of(List.of(params));
     }
 
     public Ptr(Element e) {
-        var rev = new ArrayList<CharSequence>();
-        while (e != null) {
+        var packageName = "";
+        var reversedClassName = new ArrayList<CharSequence>();
+        String memberName = null;
+        List<String> params = null;
+        for (; e != null; e = e.getEnclosingElement()) {
             if (e instanceof PackageElement) {
                 var pkg = (PackageElement) e;
-                if (!pkg.isUnnamed()) rev.add(pkg.getQualifiedName());
+                packageName = pkg.getQualifiedName().toString();
             } else if (e instanceof TypeElement) {
                 var type = (TypeElement) e;
-                rev.add(type.getSimpleName());
+                reversedClassName.add(type.getSimpleName());
             } else if (e instanceof ExecutableElement) {
                 var method = (ExecutableElement) e;
-                // TODO overloads
-                rev.add(method.toString());
+                memberName = method.getSimpleName().toString();
+                params = new ArrayList<String>();
+                for (var p : method.getParameters()) {
+                    var type = p.asType();
+                    var erased = erasure(type);
+                    if (erased == null) params.add("java.lang.Object");
+                    else params.add(erased.toString());
+                }
             } else if (e instanceof VariableElement) {
                 var field = (VariableElement) e;
-                rev.add(field.getSimpleName());
+                memberName = field.getSimpleName().toString();
             }
-            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;
+        this.packageName = packageName;
+        this.className = reverseAndJoin(reversedClassName, ".");
+        this.memberName = Optional.ofNullable(memberName);
+        this.erasedParameterTypes = Optional.ofNullable(params);
+    }
+
+    private static TypeMirror erasure(TypeMirror t) {
+        // Erase class by removing arguments
+        if (t instanceof DeclaredType) {
+            var d = (DeclaredType) t;
+            return d.asElement().asType();
+        }
+        // Erase wildcard to upper bound
+        if (t instanceof WildcardType) {
+            var w = (WildcardType) t;
+            return w.getExtendsBound();
+        }
+        // Erase type var to upper bound
+        if (t instanceof TypeVariable) {
+            var v = (TypeVariable) t;
+            return v.getUpperBound();
+        }
+        return t;
     }
 
     private static String reverseAndJoin(List<CharSequence> parts, String sep) {
@@ -62,21 +129,125 @@ public class Ptr {
         return join.toString();
     }
 
+    // TODO eliminate className() everywhere in the codebase in favor of simpleClassName() and qualifiedClassName()
+    public String qualifiedClassName() {
+        if (packageName.isEmpty()) return className;
+        return packageName + "." + className;
+    }
+
+    public static final int NOT_MATCHED = 100;
+
+    public int fuzzyMatch(TreePath path) {
+        if (!packageName(path).equals(packageName)) return NOT_MATCHED;
+        if (!simpleClassName(path).equals(className)) return NOT_MATCHED;
+        // Methods
+        if (erasedParameterTypes.isPresent()) {
+            if (!(path.getLeaf() instanceof MethodTree)) return NOT_MATCHED;
+            var method = (MethodTree) path.getLeaf();
+            if (!method.getName().contentEquals(memberName.get())) return NOT_MATCHED;
+            if (method.getParameters().size() != erasedParameterTypes.get().size()) return NOT_MATCHED;
+            var mismatch = 0;
+            for (var i = 0; i < method.getParameters().size(); i++) {
+                var type = method.getParameters().get(i).getType();
+                var name = fuzzyTypeName(type);
+                var expected = erasedParameterTypes.get().get(i);
+                if (!expected.endsWith(name)) mismatch++;
+            }
+            return mismatch;
+        }
+        // Fields
+        if (memberName.isPresent()) {
+            if (!(path.getLeaf() instanceof VariableTree)) return NOT_MATCHED;
+            var field = (VariableTree) path.getLeaf();
+            if (!field.getName().contentEquals(memberName.get())) return NOT_MATCHED;
+            return 0;
+        }
+        // Classes
+        return 0;
+    }
+
+    private String packageName(TreePath path) {
+        return Objects.toString(path.getCompilationUnit().getPackageName(), "");
+    }
+
+    private String simpleClassName(TreePath path) {
+        var reversedClassName = new ArrayList<CharSequence>();
+        for (; path != null; path = path.getParentPath()) {
+            if (path.getLeaf() instanceof ClassTree) {
+                var cls = (ClassTree) path.getLeaf();
+                reversedClassName.add(cls.getSimpleName());
+            }
+        }
+        return reverseAndJoin(reversedClassName, ".");
+    }
+
+    private String fuzzyTypeName(Tree type) {
+        class FindTypeName extends TreeScanner<Void, Void> {
+            String found = "";
+
+            @Override
+            public Void visitIdentifier(IdentifierTree t, Void __) {
+                found = t.getName().toString();
+                return null;
+            }
+
+            @Override
+            public Void visitPrimitiveType(PrimitiveTypeTree t, Void __) {
+                found = t.getPrimitiveTypeKind().name();
+                return null;
+            }
+        }
+        var find = new FindTypeName();
+        find.scan(type, null);
+        if (find.found.isEmpty()) {
+            LOG.warning(
+                    String.format(
+                            "Couldn't find type name for %s `%s`",
+                            type.getClass().getName(), Parser.describeTree(type)));
+        }
+        return find.found;
+    }
+
+    public static boolean canPoint(Element e) {
+        var inLeaf = true;
+        for (; e != null; e = e.getEnclosingElement()) {
+            var isLeaf = e instanceof ExecutableElement || e instanceof VariableElement;
+            if (inLeaf && !isLeaf) inLeaf = false;
+            if (!inLeaf && isLeaf) return false;
+        }
+        return true;
+    }
+
     @Override
     public boolean equals(Object other) {
         if (!(other instanceof Ptr)) return false;
         var that = (Ptr) other;
-        return this.path.equals(that.path);
+        return Objects.equals(this.packageName, that.packageName)
+                && Objects.equals(this.className, that.className)
+                && Objects.equals(that.memberName, that.memberName)
+                && Objects.equals(this.erasedParameterTypes, that.erasedParameterTypes);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(path);
+        return Objects.hash(packageName, className, memberName, erasedParameterTypes);
     }
 
     @Override
     public String toString() {
-        return path;
+        var s = new StringBuilder();
+        if (!packageName.isEmpty()) {
+            s.append(packageName).append('/');
+        }
+        s.append(className);
+        if (memberName.isPresent()) {
+            s.append('#').append(memberName.get());
+        }
+        if (erasedParameterTypes.isPresent()) {
+            var join = String.join(",", erasedParameterTypes.get());
+            s.append('(').append(join).append(')');
+        }
+        return s.toString();
     }
 
     private static final Logger LOG = Logger.getLogger("main");