- Add warnings for deprecated DRL syntax when used in DRL6

- WIP docs

drools-docs/src/modules/ROOT/pages/language-reference/_language-level.adoc

@@ -0,0 +1,22 @@
+////
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing,
+  software distributed under the License is distributed on an
+  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+  KIND, either express or implied.  See the License for the
+  specific language governing permissions and limitations
+  under the License.
+////
+
+[id='language-level_drl-rules']
+
+= Language Level

drools-docs/src/modules/ROOT/pages/release-notes/_release-notes-10.1.adoc

@@ -0,0 +1,33 @@
+////
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing,
+  software distributed under the License is distributed on an
+  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+  KIND, either express or implied.  See the License for the
+  specific language governing permissions and limitations
+  under the License.
+////
+
+== 10.1.0 release notes
+
+=== Language Level DRL10
+New language level DRL10 has been added. DRL10 is handled by the new parser based on ANTLR4.
+
+DRL10 introduces the following changes mainly to reduce ambiguity:
+
+* Require a prefix '##' to custom operators
+* Drop half constraint syntax
+* Drop double ampersand as infix and
+* Drop double pipe as infix or
+* Drop annotation inside LHS except @watch
+
+

drools-drl/drools-drl-ast/src/main/java/org/drools/drl/ast/dsl/DescrBuilder.java

@@ -88,4 +88,14 @@ public DescrBuilder<P, T> endLocation( int line,
      * @return
      */
     public P end();
+
+    /**
+     * Returns the parent container of this descr builder.
+     * Example: ruleDescrBuilder.getParent() will return the
+     * PackageDescrBuilder as that is its parent container
+     * without ending the current construction.
+     *
+     * @return
+     */
+    public P getParent();
 }

drools-drl/drools-drl-ast/src/main/java/org/drools/drl/ast/dsl/impl/BaseDescrBuilderImpl.java

@@ -72,4 +72,8 @@ public P end() {
         return parent;
     }
 
+    @Override
+    public P getParent() {
+        return parent;
+    }
 }

drools-drl/drools-drl-parser-tests/src/test/java/org/drools/drl/parser/antlr4/DRLExprParserTest.java

@@ -576,4 +576,48 @@ void newBigDecimal() {
         assertThat(bind.getVariable()).isEqualTo("$bd");
         assertThat(bind.getExpression()).isEqualTo("new BigDecimal(30)");
     }
+
+    @Test
+    void halfConstraintAnd() {
+        String source = "age > 10 && < 20";
+        parser.parse(source);
+
+        if (DrlParser.ANTLR4_PARSER_ENABLED) {
+            // half constraint is dropped in DRL10
+            assertThat(parser.hasErrors()).isTrue();
+        } else {
+            assertThat(parser.hasErrors()).as(parser.getErrors().toString()).isFalse();
+        }
+    }
+
+    @Test
+    void halfConstraintOr() {
+        String source = "name == \"John\" || == \"Paul\"";
+        parser.parse(source);
+
+        if (DrlParser.ANTLR4_PARSER_ENABLED) {
+            // half constraint is dropped in DRL10
+            assertThat(parser.hasErrors()).isTrue();
+        } else {
+            assertThat(parser.hasErrors()).as(parser.getErrors().toString()).isFalse();
+        }
+    }
+
+    @Test
+    void customOperator() {
+        Operator.addOperatorToRegistry("supersetOf", false);
+        // prefix '##' is required for custom operators in DRL10
+        String source = DrlParser.ANTLR4_PARSER_ENABLED ? "this ##supersetOf $list" : "this supersetOf $list";
+        ConstraintConnectiveDescr result = parser.parse(source);
+        assertThat(parser.hasErrors()).as(parser.getErrors().toString()).isFalse();
+
+        RelationalExprDescr rel = (RelationalExprDescr) result.getDescrs().get(0);
+        assertThat(rel.getOperator()).isEqualTo("supersetOf");
+
+        AtomicExprDescr left = (AtomicExprDescr) rel.getLeft();
+        assertThat(left.getExpression()).isEqualTo("this");
+
+        AtomicExprDescr right = (AtomicExprDescr) rel.getRight();
+        assertThat(right.getExpression()).isEqualTo("$list");
+    }
 }

drools-drl/drools-drl-parser-tests/src/test/java/org/drools/drl/parser/antlr4/MiscDRLParserTest.java

@@ -5320,4 +5320,24 @@ void typeDeclarationWithTypeToken() {
         TypeFieldDescr typeFieldDescr = typeDeclarationDescr.getFields().get("id");
         assertThat(typeFieldDescr.getPattern().getObjectType()).isEqualTo("int");
     }
+
+    @Test
+    void agendaGroup() {
+        final String drl = "rule R1\n" +
+                "  agenda-group \"group1\"\n" +
+                "  when\n" +
+                "  then\n" +
+                "end";
+        PackageDescr pkg = parseAndGetPackageDescrWithoutErrorCheck(drl);
+        if (DrlParser.ANTLR4_PARSER_ENABLED) {
+            // agenda-group is dropped in DRL10
+            assertThat(parser.hasErrors()).isTrue();
+        } else {
+            RuleDescr rule = pkg.getRules().get(0);
+            assertThat(rule).isNotNull();
+            final AttributeDescr att = rule.getAttributes().get("agenda-group");
+            assertThat(att.getValue()).isEqualTo("group1");
+            assertThat(att.getName()).isEqualTo("agenda-group");
+        }
+    }
 }

drools-drl/drools-drl-parser/src/main/java/org/drools/drl/parser/DrlParser.java

@@ -74,6 +74,11 @@ public DrlParser() {
 
     public DrlParser(LanguageLevelOption languageLevel) {
         this.languageLevel = languageLevel;
+
+        if (languageLevel == LanguageLevelOption.DRL5 || languageLevel == LanguageLevelOption.DRL6_STRICT) {
+            LOG.warn("{} is deprecated and will be removed in future versions. Please use the default {} or newly introduced {} instead.",
+                     languageLevel, LanguageLevelOption.DRL6, LanguageLevelOption.DRL10);
+        }
     }
 
     /** Parse a rule from text */