8241187: ToolBox::grep should allow for negative filtering

Reviewed-by: vromero

test/langtools/tools/javac/toolbox/TestGrepOfToolBox.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8241187
+ * @summary ToolBox::grep should allow for negative filtering
+ * @library /tools/lib
+ * @build toolbox.ToolBox
+ * @run main TestGrepOfToolBox
+ */
+
+import java.util.Arrays;
+import java.util.List;
+
+import toolbox.ToolBox;
+
+public class TestGrepOfToolBox {
+    public static void main(String[] args) {
+        ToolBox tb = new ToolBox();
+        List<String> input = Arrays.asList("apple", "banana", "cat", "dog", "end", "ending");
+
+        String regex1 = ".*ana.*";
+        List<String> expected1 = Arrays.asList("apple", "cat", "dog", "end", "ending");
+        List<String> output1 = tb.grep(regex1, input, false);
+        tb.checkEqual(expected1, output1);
+
+        String regex2 = ".*nd.*";
+        List<String> expected2 = Arrays.asList("apple", "banana", "cat", "dog");
+        List<String> output2 = tb.grep(regex2, input, false);
+        tb.checkEqual(expected2, output2);
+
+        String regex3 = "apple";
+        List<String> expected3 = Arrays.asList("banana", "cat", "dog", "end", "ending");
+        List<String> output3 = tb.grep(regex3, input, false);
+        tb.checkEqual(expected3, output3);
+
+        String regex4 = ".*ana.*";
+        List<String> expected4 = Arrays.asList("banana");
+        List<String> output4 = tb.grep(regex4, input, true);
+        tb.checkEqual(expected4, output4);
+
+        String regex5 = ".*nd.*";
+        List<String> expected5 = Arrays.asList("end", "ending");
+        List<String> output5 = tb.grep(regex5, input, true);
+        tb.checkEqual(expected5, output5);
+
+        String regex6 = "apple";
+        List<String> expected6 = Arrays.asList("apple");
+        List<String> output6 = tb.grep(regex6, input, true);
+        tb.checkEqual(expected6, output6);
+    }
+}

test/langtools/tools/lib/toolbox/ToolBox.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -164,24 +164,50 @@ public class ToolBox {
     }
 
     /**
-     * Filters a list of strings according to the given regular expression.
+     * Filters a list of strings according to the given regular expression,
+     * returning the strings that match the regular expression.
      * @param regex the regular expression
      * @param lines the strings to be filtered
      * @return the strings matching the regular expression
      */
     public List<String> grep(String regex, List<String> lines) {
-        return grep(Pattern.compile(regex), lines);
+        return grep(Pattern.compile(regex), lines, true);
     }
 
     /**
-     * Filters a list of strings according to the given regular expression.
+     * Filters a list of strings according to the given regular expression,
+     * returning the strings that match the regular expression.
      * @param pattern the regular expression
      * @param lines the strings to be filtered
      * @return the strings matching the regular expression
      */
     public List<String> grep(Pattern pattern, List<String> lines) {
+        return grep(pattern, lines, true);
+    }
+
+    /**
+     * Filters a list of strings according to the given regular expression,
+     * returning either the strings that match or the strings that do not match.
+     * @param regex the regular expression
+     * @param lines the strings to be filtered
+     * @param match if true, return the lines that match; otherwise if false, return the lines that do not match.
+     * @return the strings matching(or not matching) the regular expression
+     */
+    public List<String> grep(String regex, List<String> lines, boolean match) {
+        return grep(Pattern.compile(regex), lines, match);
+    }
+
+    /**
+     * Filters a list of strings according to the given regular expression,
+     * returning either the strings that match or the strings that do not match.
+     * @param pattern the regular expression
+     * @param lines the strings to be filtered
+     * @param match if true, return the lines that match; otherwise if false, return the lines that do not match.
+     * @return the strings matching(or not matching) the regular expression
+     */
+    public List<String> grep(Pattern pattern, List<String> lines, boolean match) {
         return lines.stream()
-                .filter(s -> pattern.matcher(s).find())
+                .filter(s -> pattern.matcher(s).find() == match)
                 .collect(Collectors.toList());
     }