[DO-NOT-MERGE][WIP][incubator-kie-drools-6220] Slim down DRL syntax with New Antlr4 Parser

.github/workflows/pr-downstream.yml

@@ -33,6 +33,7 @@ on:
 
 jobs:
   kogito-downstream-build:
+    if: false
     concurrency:
       group: pr-${{ matrix.job_name }}_${{ matrix.os }}_${{ matrix.java-version }}_${{ matrix.maven-version }}_${{ github.head_ref }}
       cancel-in-progress: true

.github/workflows/pr-drools.yml

@@ -61,7 +61,7 @@ jobs:
       - name: Build Chain
         uses: apache/incubator-kie-kogito-pipelines/.ci/actions/build-chain@main
         env:
-          BUILD_MVN_OPTS_CURRENT: '-Dfull -Dreproducible'
+          BUILD_MVN_OPTS_CURRENT: '-Dfull -Dreproducible -DenableNewParser'
           MAVEN_OPTS: "-Dfile.encoding=UTF-8"
         with:
           definition-file: https://raw.githubusercontent.com/${GROUP:apache}/incubator-kie-kogito-pipelines/${BRANCH:main}/.ci/pull-request-config.yaml

.gitignore

@@ -29,6 +29,7 @@ nbproject
 *.ipr
 *.iws
 *.iml
+build.log
 
 # generated files
 dependency-reduced-pom.xml

drools-drl/drools-drl-ast/src/main/java/org/drools/drl/ast/descr/OperatorDescr.java

@@ -26,6 +26,9 @@
 public class OperatorDescr extends BaseDescr {
     private static final long serialVersionUID = 520l;
 
+    // prefix for custom operators which are not built-in
+    public static final String CUSTOM_OPERATOR_PREFIX = "##";
+
     private String            operator;
     private boolean           negated;
     private List<String>      parameters;
@@ -55,7 +58,15 @@ public String getOperator() {
     }
 
     public void setOperator( String operator ) {
-        this.operator = operator != null ? operator.trim() : null;
+        this.operator = operator != null ? trimOperator(operator) : null;
+    }
+
+    private String trimOperator(String operator) {
+        operator = operator.trim();
+        if (operator.startsWith(CUSTOM_OPERATOR_PREFIX)) {
+            operator = operator.substring(CUSTOM_OPERATOR_PREFIX.length());
+        }
+        return operator;
     }
 
     public boolean isNegated() {

drools-drl/drools-drl-parser-tests/src/test/java/org/drools/drl/parser/antlr4/DRLParserTest.java → drools-drl/drools-drl-parser-tests/src/test/java/org/drools/drl/parser/antlr4/DRL10ParserTest.java

@@ -31,14 +31,14 @@
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.drools.drl.parser.antlr4.DRLParserHelper.computeTokenIndex;
-import static org.drools.drl.parser.antlr4.DRLParserHelper.createDrlParser;
-import static org.drools.drl.parser.antlr4.DRLParserHelper.parse;
+import static org.drools.drl.parser.antlr4.DRL10ParserHelper.computeTokenIndex;
+import static org.drools.drl.parser.antlr4.DRL10ParserHelper.createDrlParser;
+import static org.drools.drl.parser.antlr4.DRL10ParserHelper.parse;
 
 /**
  * This test class is specific to new antlr4 parser.
  */
-class DRLParserTest {
+class DRL10ParserTest {
 
     private static final String drl =
             "package org.test;\n" +
@@ -94,7 +94,7 @@ void parse_basicRule() {
 
     @Test
     void computeTokenIndex_basicRule() {
-        DRLParser parser = createDrlParser(drl);
+        DRL10Parser parser = createDrlParser(drl);
         parser.compilationUnit();
 
         assertThat((int) computeTokenIndex(parser, 1, 0)).isEqualTo(0);

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

@@ -27,7 +27,6 @@
 import org.drools.drl.ast.descr.ConstraintConnectiveDescr;
 import org.drools.drl.ast.descr.RelationalExprDescr;
 import org.drools.drl.parser.DrlExprParser;
-import org.drools.drl.parser.DrlExprParserFactory;
 import org.drools.drl.parser.DrlParser;
 import org.drools.drl.parser.DroolsParserException;
 import org.drools.drl.parser.impl.Operator;
@@ -38,7 +37,6 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.EnumSource;
 import org.junit.jupiter.params.provider.ValueSource;
-import org.kie.internal.builder.conf.LanguageLevelOption;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assumptions.assumeFalse;
@@ -52,7 +50,7 @@ class DRLExprParserTest {
 
     @BeforeEach
     void setUp() {
-        this.parser = DrlExprParserFactory.getDrlExprParser(LanguageLevelOption.DRL6);
+        this.parser = ParserTestUtils.getExprParser();
     }
 
     @AfterEach
@@ -175,7 +173,7 @@ void bindingConstraint() {
 
     @Test
     void bindingWithRestrictions() {
-        String source = "$x : property > value && < 20";
+        String source = "$x : property > value && property < 20";
         ConstraintConnectiveDescr result = parser.parse( source );
         assertThat(parser.hasErrors()).as(parser.getErrors().toString()).isFalse();
 
@@ -458,7 +456,7 @@ void noViableAlt() {
             assertThat(exception.getColumn()).isEqualTo(2);
             assertThat(exception.getOffset()).isEqualTo(2);
             assertThat(exception.getMessage())
-                    .isEqualToIgnoringCase("[ERR 101] Line 1:2 no viable alternative at input 'a'");
+                    .isEqualToIgnoringCase("[ERR 101] Line 1:2 no viable alternative at input '~a'");
         } else {
             assertThat(parser.hasErrors()).isFalse();
         }

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

@@ -24,13 +24,12 @@
 import org.drools.drl.ast.descr.BindingDescr;
 import org.drools.drl.ast.descr.ConstraintConnectiveDescr;
 import org.drools.drl.parser.DrlExprParser;
-import org.drools.drl.parser.DrlExprParserFactory;
 import org.drools.mvel.evaluators.MatchesEvaluatorsDefinition;
 import org.drools.mvel.evaluators.SetEvaluatorsDefinition;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
-import org.kie.internal.builder.conf.LanguageLevelOption;
+import org.junit.jupiter.api.condition.DisabledIfSystemProperty;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -47,6 +46,7 @@ void setUp() {
         dumper = new DescrDumper();
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void dump() {
         String input = "price > 10 && < 20 || == $val || == 30";
@@ -147,6 +147,7 @@ void dumpWithDateAttr() {
         assertThat(result).isEqualTo(expected);
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void dumpComplex() {
         String input = "a ( > 60 && < 70 ) || ( > 50 && < 55 ) && a3 == \"black\" || a == 40 && a3 == \"pink\" || a == 12 && a3 == \"yellow\" || a3 == \"blue\"";
@@ -220,6 +221,7 @@ void dumpBindings4() {
         assertThat(result).isEqualTo(expected);
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void dumpBindingsWithRestriction() {
         String input = "$x : age > 10 && < 20 || > 30";
@@ -360,7 +362,7 @@ void processImplicitConstraints() {
     }
 
     public ConstraintConnectiveDescr parse(final String constraint) {
-        DrlExprParser parser = DrlExprParserFactory.getDrlExprParser(LanguageLevelOption.DRL6);
+        DrlExprParser parser = ParserTestUtils.getExprParser();
         ConstraintConnectiveDescr result = parser.parse(constraint);
         assertThat(parser.hasErrors()).as(parser.getErrors().toString()).isFalse();
 

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

@@ -74,8 +74,9 @@
 import org.drools.drl.parser.DroolsParserException;
 import org.drools.drl.parser.impl.Operator;
 import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledIfSystemProperty;
+import org.junit.jupiter.api.condition.EnabledIfSystemProperty;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
@@ -873,6 +874,7 @@ void simpleRuleWithBindings() {
         assertThat((String) rule.getConsequence()).isEqualToIgnoringWhitespace("if ( a == b ) { " + "  assert( foo3 );" + "} else {" + "  retract( foo4 );" + "}" + "  System.out.println( a4 );");
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void multipleRestrictionsConstraint() {
         RuleDescr rule = parseAndGetFirstRuleDescrFromFile("restrictions_test.drl");
@@ -2444,7 +2446,7 @@ void inOperator() {
         assertThat(pattern.getConstraint().getDescrs()).hasSize(1);
 
         ExprConstraintDescr fld = (ExprConstraintDescr) pattern.getConstraint().getDescrs().get(0);
-        assertThat(fld.getExpression()).isEqualTo("age > 30 && < 40");
+        assertThat(fld.getExpression()).isEqualTo("age > 30 && age < 40");
 
         // the second col, with 2 fields, the first with 2 restrictions, the
         // second field with one
@@ -2478,7 +2480,7 @@ void notInOperator() {
         assertThat(pattern.getConstraint().getDescrs()).hasSize(1);
 
         ExprConstraintDescr fld = (ExprConstraintDescr) pattern.getConstraint().getDescrs().get(0);
-        assertThat(fld.getExpression()).isEqualTo("age > 30 && < 40");
+        assertThat(fld.getExpression()).isEqualTo("age > 30 && age < 40");
 
         // the second col, with 2 fields, the first with 2 restrictions, the
         // second field with one
@@ -2528,6 +2530,7 @@ void constraintOrConnective() {
         assertThat(fcd.getExpression()).isEqualToIgnoringWhitespace("age < 42 || location==\"atlanta\"");
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void restrictions() {
         final String text = "rule X when Foo( bar > 1 || == 1 ) then end\n";
@@ -2979,7 +2982,7 @@ void pluggableOperators() {
         assertThat(eventE.getConstraint().getDescrs()).hasSize(1);
 
         ExprConstraintDescr fcdE = (ExprConstraintDescr) eventE.getConstraint().getDescrs().get(0);
-        assertThat(fcdE.getExpression()).isEqualTo("this not before[1, 10] $b || after[1, 10] $c && this after[1, 5] $d");
+        assertThat(fcdE.getExpression()).isEqualTo("this not before[1, 10] $b || this after[1, 10] $c && this after[1, 5] $d");
     }
 
     @Test
@@ -3888,6 +3891,7 @@ void constraintOperators(String constraint) {
         assertThat(exprConstraintDescr.getExpression()).isEqualToIgnoringWhitespace(constraint);
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @ParameterizedTest
     @ValueSource(strings = {
             "country matches \"[a-z]*\" || matches \"[A-Z]*\"",
@@ -4053,6 +4057,7 @@ void lhsPatternAnnotation() {
         assertThat(annotationDescr.getSingleValueAsString()).isEqualTo("!*, age");
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void prefixAndDescrAnnotation() {
         final String text =
@@ -4074,6 +4079,7 @@ void prefixAndDescrAnnotation() {
         assertThat(andDescr.getDescrs()).hasSize(2);
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void prefixOrDescrAnnotation() {
         final String text =
@@ -4096,6 +4102,7 @@ void prefixOrDescrAnnotation() {
         assertThat(orDescr.getDescrs()).hasSize(2);
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void infixAndDescrAnnotation() {
         final String text =
@@ -4116,6 +4123,7 @@ void infixAndDescrAnnotation() {
         assertThat(andDescr.getDescrs()).hasSize(3);
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void infixOrDescrAnnotation() {
         final String text =
@@ -4411,8 +4419,9 @@ void traitExtendsMultiple() {
                 .containsExactlyInAnyOrder("com.sample.ParentTrait", "UncleTrait", "org.test.GrandParentTrait");
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
-    void pluggableEvaluator() {
+    void pluggableEvaluatorOldParser() {
         final String source = "package org.drools\n" +
                 "rule R\n" +
                 "when\n" +
@@ -4431,6 +4440,27 @@ void pluggableEvaluator() {
                 .containsExactly("$c : core", "this not isA t.x.E.class", "this isA t.x.D.class");
     }
 
+    @EnabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
+    @Test
+    void pluggableEvaluatorNewParser() {
+        final String source = "package org.drools\n" +
+                "rule R\n" +
+                "when\n" +
+                "   $t : Thing( $c : core, this not ##isA t.x.E.class, this ##isA t.x.D.class )\n" +
+                "then\n" +
+                "   list.add( \"E\" ); \n" +
+                "   don( $t, E.class ); \n" +
+                "end\n";
+
+        Operator.addOperatorToRegistry("isA", false);
+        Operator.addOperatorToRegistry("isA", true);
+
+        PatternDescr pattern = (PatternDescr) parseAndGetFirstRuleDescr(source).getLhs().getDescrs().get(0);
+        assertThat(pattern.getConstraint().getDescrs())
+                .extracting(Object::toString)
+                .containsExactly("$c : core", "this not ##isA t.x.E.class", "this ##isA t.x.D.class");
+    }
+
     @Test
     void namedConsequenceDo() {
         final String text =
@@ -5114,6 +5144,7 @@ void accumulateEmptyChunks() {
         assertThat(accumulateDescr.getResultCode()).isEqualTo("null");
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void doublePipeInfixOr() {
         final String text =
@@ -5135,6 +5166,7 @@ void doublePipeInfixOr() {
         });
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void doubleAmpersandInfixAnd() {
         final String text =
@@ -5154,6 +5186,7 @@ void doubleAmpersandInfixAnd() {
         });
     }
 
+    @DisabledIfSystemProperty(named = "drools.drl.antlr4.parser.enabled", matches = "true")
     @Test
     void doubleAmpersandInfixAndInAccumulate() {
         final String text =

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

@@ -21,7 +21,10 @@
 import java.util.Arrays;
 import java.util.List;
 
+import org.drools.drl.parser.DrlExprParser;
+import org.drools.drl.parser.DrlExprParserFactory;
 import org.drools.drl.parser.DrlParser;
+import org.kie.internal.builder.conf.LanguageLevelOption;
 
 public class ParserTestUtils {
 
@@ -45,14 +48,22 @@ private ParserTestUtils() {
      * Returns a DrlParser which encapsulates an old or new parser depending on system property
      */
     public static DrlParser getParser() {
-        return new DrlParser();
+        if (DrlParser.ANTLR4_PARSER_ENABLED) {
+            return new DrlParser(LanguageLevelOption.DRL10);
+        } else {
+            return new DrlParser(LanguageLevelOption.DRL6);
+        }
     }
 
     /**
-     * Enables the old parser. Just for quick testing purposes.
+     * Returns a DrlExprParser which encapsulates an old or new parser depending on system property
      */
-    public static void enableOldParser() {
-        DrlParser.ANTLR4_PARSER_ENABLED = false;
+    public static DrlExprParser getExprParser() {
+        if (DrlParser.ANTLR4_PARSER_ENABLED) {
+            return DrlExprParserFactory.getDrlExprParser(LanguageLevelOption.DRL10);
+        } else {
+            return DrlExprParserFactory.getDrlExprParser(LanguageLevelOption.DRL6);
+        }
     }
 
     public static List<String> javaKeywords() {

drools-drl/drools-drl-parser-tests/src/test/resources/org/drools/drl/parser/antlr4/accumulate_with_nested_from.drl

@@ -18,7 +18,7 @@
 rule "AccumulateParserTest"
 when
      // below statement makes no sense, but is useful to test parsing recursiveness
-     $personList : ArrayList() from accumulate( Person( $age : age > 21 || < 10 ) from collect( People() from $town.getPeople() ),
+     $personList : ArrayList() from accumulate( Person( $age : age > 21 || age < 10 ) from collect( People() from $town.getPeople() ),
                                                 max( $age ) );
 then
 end

drools-drl/drools-drl-parser-tests/src/test/resources/org/drools/drl/parser/antlr4/in_operator_test.drl

@@ -19,7 +19,7 @@
 
 rule simple_rule 
   when
-      Person(age > 30 && < 40)
+      Person(age > 30 && age < 40)
       Vehicle(type in ( "sedan", "wagon" ), age < 3)
   then
     consequence();

drools-drl/drools-drl-parser-tests/src/test/resources/org/drools/drl/parser/antlr4/notin_operator_test.drl

@@ -19,7 +19,7 @@
 
 rule simple_rule 
   when
-      Person(age > 30 && < 40)
+      Person(age > 30 && age < 40)
       Vehicle(type not in ( "sedan", "wagon" ), age < 3)
   then
     consequence();