Introduce ANTLR grammar for ModelJoin to start replacing custom parser

.gitignore

@@ -177,3 +177,7 @@ local.properties
 output/
 doc/
 [lL]ocal[tT]est*
+
+# ANTLR
+
+gen/

build.sbt

+import com.simplytyped.Antlr4Plugin.autoImport.antlr4PackageName
 import sbt.Keys.{libraryDependencies, scalacOptions, version}
 
 val emfcommonVersion = "2.12.0"
@@ -40,5 +41,10 @@ lazy val generator = (project in file("."))
       case x =>
         val oldStrategy = (assemblyMergeStrategy in assembly).value
         oldStrategy(x)
-    }
-  ).dependsOn(syncProvider, rsumProvider)
+    },
+  ).dependsOn(
+    syncProvider,
+    rsumProvider
+  ).enablePlugins(Antlr4Plugin)
+
+antlr4PackageName in Antlr4 := Some("org.rosi_project.model_sync.model_join.representation.parser.antlr.generated")

project/sbt-antlr4.sbt

+
+addSbtPlugin("com.simplytyped" % "sbt-antlr4" % "0.8.2")

src/main/antlr4/ModelJoin.g4

+/*
+ * ModelJoin.g4
+ *
+ * Defines the structure of our ModelJoin grammar
+ *
+ * Author: Rico Bergmann
+ */
+grammar ModelJoin;
+
+/*
+ * Parser
+ */
+
+modeljoin : join+ EOF;
+join  : (naturaljoin | thetajoin | outerjoin) 'as' CLASSRES
+  ( '{'
+  keepattributes*
+  keepaggregate*
+  keepexpressions*
+  '}' )? ;
+
+naturaljoin : 'natural' 'join' CLASSRES 'with' CLASSRES ;
+thetajoin : 'theta' 'join' CLASSRES 'with' CLASSRES 'where' OCLCOND ;
+outerjoin : (leftouterjoin | rightouterjoin) 'outer' 'join' CLASSRES 'with' CLASSRES ;
+leftouterjoin : 'left' ;
+rightouterjoin  : 'right' ;
+
+keepattributes  : 'keep' 'attributes' ATTRRES ( ',' ATTRRES )* ;
+keepaggregate : 'keep' 'aggregate' aggrtype '(' RELATTRRES ')' 'over' ATTRRES 'as' CLASSRES ;
+keepexpressions : (keeptypeexpr | keepoutgoingexpr | keepincomingexpr)
+ ( '{'
+  keepattributes*
+  keepaggregate*
+  keepexpressions*
+ '}' )? ;
+keeptypeexpr  :  keepsupertypeexpr | keepsubtypeexpr ;
+keepsupertypeexpr : 'keep' 'supertype' CLASSRES ( 'as' 'type' CLASSRES )? ;
+keepsubtypeexpr : 'keep' 'subtype' CLASSRES ( 'as' 'type' CLASSRES )? ;
+keepoutgoingexpr  : 'keep' 'outgoing' ATTRRES ( 'as' 'type' CLASSRES )? ;
+keepincomingexpr  : 'keep' 'incoming' ATTRRES ( 'as' 'type' CLASSRES )? ;
+
+aggrtype : SUMAGGR | AVGAGGR | MINAGGR | MAXAGGR | SIZEAGGR ;
+
+/*
+ * Lexer
+ */
+
+fragment LOWERCASE  : [a-z] ;
+fragment UPPERCASE  : [A-Z] ;
+fragment ANYCASE  : LOWERCASE | UPPERCASE ;
+fragment DIGIT  : [0-9] ;
+
+fragment EELEMENTID  : ANYCASE | (ANYCASE | '_')+(ANYCASE | DIGIT | '_')+ ;
+
+CLASSRES  : EELEMENTID ( '.' EELEMENTID )* ;
+RELATTRRES  : EELEMENTID ;
+ATTRRES : CLASSRES '.' RELATTRRES ;
+OCLCOND : .+? ;
+
+SUMAGGR : 'sum' ;
+AVGAGGR : 'avg' ;
+MINAGGR : 'min' ;
+MAXAGGR : 'max' ;
+SIZEAGGR  : 'size' ;
+
+WHITESPACE  : ' ' -> skip ;
+NEWLINE : ('\r'? '\n' | '\r')+ -> skip ;