#919 - io.ebean package initial

src/main/java/io/ebeaninternal/server/grammer/EqlParser.java

@@ -0,0 +1,48 @@
+package io.ebeaninternal.server.grammer;
+
+import io.ebeaninternal.api.SpiQuery;
+import io.ebeaninternal.server.grammer.antlr.EQLLexer;
+import io.ebeaninternal.server.grammer.antlr.EQLParser;
+import org.antlr.v4.runtime.ANTLRInputStream;
+import org.antlr.v4.runtime.BaseErrorListener;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.RecognitionException;
+import org.antlr.v4.runtime.Recognizer;
+import org.antlr.v4.runtime.tree.ParseTreeWalker;
+
+/**
+ * Parse EQL query language applying it to an ORM query object.
+ */
+public class EqlParser {
+
+  private static final ErrorListener errorListener = new ErrorListener();
+
+  /**
+   * Parse the raw EQL query and apply it to the supplied query.
+   */
+  public static <T> void parse(String raw, SpiQuery<T> query) {
+
+    EQLLexer lexer = new EQLLexer(new ANTLRInputStream(raw));
+    CommonTokenStream tokens = new CommonTokenStream(lexer);
+    EQLParser parser = new EQLParser(tokens);
+    parser.addErrorListener(errorListener);
+    EQLParser.Select_statementContext context = parser.select_statement();
+
+    EqlAdapter<T> adapter = new EqlAdapter<>(query);
+
+    ParseTreeWalker walker = new ParseTreeWalker();
+    walker.walk(adapter, context);
+
+    query.simplifyExpressions();
+  }
+
+  static class ErrorListener extends BaseErrorListener {
+
+    @Override
+    public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int line, int charPositionInLine, String msg, RecognitionException e) {
+
+      String reportMsg = "line " + line + ":" + charPositionInLine + " " + msg;
+      throw new IllegalArgumentException(reportMsg);
+    }
+  }
+}