[OLINGO-568] Refactored SearchParser for further development

lib/server-core/src/main/java/org/apache/olingo/server/core/uri/parser/search/SearchParser.java

@@ -21,23 +21,23 @@ package org.apache.olingo.server.core.uri.parser.search;
 import org.apache.olingo.server.api.uri.queryoption.SearchOption;
 import org.apache.olingo.server.api.uri.queryoption.search.SearchBinaryOperatorKind;
 import org.apache.olingo.server.api.uri.queryoption.search.SearchExpression;
-import org.apache.olingo.server.api.uri.queryoption.search.SearchTerm;
 import org.apache.olingo.server.core.uri.queryoption.SearchOptionImpl;
 
 import java.util.Iterator;
+import java.util.List;
 
 public class SearchParser {
 
-  protected Iterator<SearchQueryToken> tokens;
-  protected SearchExpression root;
-//  private SearchQueryToken currentToken;
+  private Iterator<SearchQueryToken> tokens;
+  private SearchExpression root;
+  private SearchQueryToken token;
 
   public SearchOption parse(String path, String value) {
     SearchTokenizer tokenizer = new SearchTokenizer();
     try {
       tokens = tokenizer.tokenize(value).iterator();
-//      currentToken = tokens.next();
-      root = processTokens();
+      nextToken();
+      root = processSearchExpression(null);
     } catch (SearchTokenizerException e) {
       return null;
     }
@@ -46,81 +46,98 @@ public class SearchParser {
     return searchOption;
   }
 
-  protected SearchExpression processTokens() {
-    SearchQueryToken token = nextToken();
-    
-    
+  protected SearchExpression parseInternal(List<SearchQueryToken> tokens) {
+    this.tokens = tokens.iterator();
+    nextToken();
+    return processSearchExpression(null);
+  }
+
+  private SearchExpression processSearchExpression(SearchExpression left) {
+    if(token == null) {
+      return left;
+    }
+
     if(token.getToken() == SearchQueryToken.Token.OPEN) {
+      processOpen();
       throw illegalState();
+    } else if(token.getToken() == SearchQueryToken.Token.CLOSE) {
+        processClose();
+        throw illegalState();
     } else if(token.getToken() == SearchQueryToken.Token.NOT) {
-      return processNot();
+      processNot();
     } else if(token.getToken() == SearchQueryToken.Token.PHRASE ||
         token.getToken() == SearchQueryToken.Token.WORD) {
-      return processTerm(token);
-//    } else if(token.getToken() == SearchQueryToken.Token.AND) {
-//      return processAnd();
+      return processSearchExpression(processTerm());
+    } else if(token.getToken() == SearchQueryToken.Token.AND) {
+        SearchExpression se = processAnd(left);
+        return processSearchExpression(se);
+    } else if(token.getToken() == SearchQueryToken.Token.OR) {
+        return processOr(left);
     } else {
       throw illegalState();
     }
-  }
-
-  private SearchExpression processAnd(SearchExpression se) {
-    SearchQueryToken token = nextToken();
-    if(token.getToken() == SearchQueryToken.Token.PHRASE ||
-        token.getToken() == SearchQueryToken.Token.WORD) {
-//      SearchExpression t = processTerm(token);
-      return new SearchBinaryImpl(se, SearchBinaryOperatorKind.AND, processTerm(token));
-    }
     throw illegalState();
   }
 
-  private SearchExpression processOr(SearchExpression se) {
-    SearchQueryToken token = nextToken();
-    if(token.getToken() == SearchQueryToken.Token.PHRASE ||
-        token.getToken() == SearchQueryToken.Token.WORD) {
-      return new SearchBinaryImpl(se, SearchBinaryOperatorKind.OR, processTerm(token));
-    }
-    throw illegalState();
+  private void processClose() {
+    nextToken();
+  }
+
+  private void processOpen() {
+    nextToken();
+  }
+
+  private SearchExpression processAnd(SearchExpression left) {
+    nextToken();
+    SearchExpression se = processTerm();
+    return new SearchBinaryImpl(left, SearchBinaryOperatorKind.AND, se);
+  }
+
+  public SearchExpression processOr(SearchExpression left) {
+    nextToken();
+    SearchExpression se = processSearchExpression(left);
+    return new SearchBinaryImpl(left, SearchBinaryOperatorKind.OR, se);
   }
 
   private RuntimeException illegalState() {
     return new RuntimeException();
   }
 
-  private SearchUnaryImpl processNot() {
-    SearchQueryToken token = nextToken();
-    if(token.getToken() == SearchQueryToken.Token.PHRASE ||
-        token.getToken() == SearchQueryToken.Token.WORD) {
-      throw illegalState();
-//      return new SearchUnaryImpl(processTerm(token));
-    }
-    throw illegalState();
+  private void processNot() {
+    nextToken();
   }
 
-  private SearchQueryToken nextToken() {
-//    if(tokens.hasNext()) {
-    return tokens.next();
-//    }
+  private void nextToken() {
+    if(tokens.hasNext()) {
+     token = tokens.next();
+    } else {
+      token = null;
+    }
 //    return null;
   }
 
-  private SearchExpression processTerm(SearchQueryToken token) {
-    SearchTerm searchTerm = new SearchTermImpl(token.getLiteral());
-    if(isEof()) {
-      return searchTerm;
+  private SearchExpression processTerm() {
+    if(token.getToken() == SearchQueryToken.Token.NOT) {
+      return new SearchUnaryImpl(processPhrase());
     }
-
-    SearchQueryToken next = nextToken();
-    if(next.getToken() == SearchQueryToken.Token.AND) {
-      return processAnd(searchTerm);
-    } else if(next.getToken() == SearchQueryToken.Token.OR) {
-      return processOr(searchTerm);
+    if(token.getToken() == SearchQueryToken.Token.PHRASE) {
+      return processPhrase();
     }
-
-    throw illegalState();
+    if(token.getToken() == SearchQueryToken.Token.WORD) {
+      return processWord();
+    }
+    return null;
   }
 
-  private boolean isEof() {
-    return !tokens.hasNext();
+  private SearchTermImpl processWord() {
+    String literal = token.getLiteral();
+    nextToken();
+    return new SearchTermImpl(literal);
+  }
+
+  private SearchTermImpl processPhrase() {
+    String literal = token.getLiteral();
+    nextToken();
+    return new SearchTermImpl(literal);
   }
 }

lib/server-core/src/main/java/org/apache/olingo/server/core/uri/parser/search/SearchTokenizer.java

@@ -442,7 +442,7 @@ public class SearchTokenizer {
    */
   public List<SearchQueryToken> tokenize(final String searchQuery)
         throws SearchTokenizerException {
-    
+
     char[] chars = searchQuery.trim().toCharArray();
 
     State state = new SearchExpressionState();

lib/server-core/src/test/java/org/apache/olingo/server/core/uri/parser/search/SearchParserAndTokenizerTest.java

@@ -34,12 +34,15 @@ public class SearchParserAndTokenizerTest {
 
   @Test
   public void basicParsing() throws SearchTokenizerException {
+//    SearchExpressionValidator.init("a AND b OR c").enableLogging()
+//        .validate(with("a"));
+
     SearchExpressionValidator.init("a")
         .validate(with("a"));
     SearchExpressionValidator.init("a AND b")
         .validate(with("a", and("b")));
     SearchExpressionValidator.init("a AND b AND c")
-        .validate(with("a", and("b", and("c"))));
+        .validate("{{'a' AND 'b'} AND 'c'}");
     SearchExpressionValidator.init("a OR b")
         .validate(with("a", or("b")));
     SearchExpressionValidator.init("a OR b OR c")
@@ -47,10 +50,11 @@ public class SearchParserAndTokenizerTest {
   }
 
   @Test
-  @Ignore("Currently not working")
   public void mixedParsing() throws Exception {
     SearchExpressionValidator.init("a AND b OR c")
-        .validate(with("c", or("a", and("b"))));
+        .validate("{{'a' AND 'b'} OR 'c'}");
+    SearchExpressionValidator.init("a OR b AND c")
+        .validate("{'a' OR {'b' AND 'c'}}");
   }
 
   @Ignore
@@ -156,15 +160,25 @@ public class SearchParserAndTokenizerTest {
     }
 
     private void validate(SearchExpression expectedSearchExpression) throws SearchTokenizerException {
+      final SearchExpression searchExpression = getSearchExpression();
+      Assert.assertEquals(expectedSearchExpression.toString(), searchExpression.toString());
+    }
+
+    private void validate(String expectedSearchExpression) throws SearchTokenizerException {
+      final SearchExpression searchExpression = getSearchExpression();
+      Assert.assertEquals(expectedSearchExpression, searchExpression.toString());
+    }
+
+    private SearchExpression getSearchExpression() {
       SearchParser tokenizer = new SearchParser();
       SearchOption result = tokenizer.parse(null, searchQuery);
       Assert.assertNotNull(result);
       final SearchExpression searchExpression = result.getSearchExpression();
       Assert.assertNotNull(searchExpression);
       if (log) {
-        System.out.println(expectedSearchExpression);
+        System.out.println(searchExpression);
       }
-      Assert.assertEquals(expectedSearchExpression.toString(), searchExpression.toString());
+      return searchExpression;
     }
   }
 

lib/server-core/src/test/java/org/apache/olingo/server/core/uri/parser/search/SearchParserTest.java

@@ -144,12 +144,21 @@ public class SearchParserTest extends SearchParser {
     SearchExpression se = run(Token.OPEN, Token.WORD, Token.AND, Token.WORD, Token.CLOSE, Token.AND, Token.WORD);
     assertEquals("{{'word1' AND 'word2'} AND 'word3'}", se.toString());
   }
-  
+
+  @Test
+  public void combinationAndOr() {
+    //word1 AND word2 OR word3
+    SearchExpression se = run(Token.WORD, Token.AND, Token.WORD, Token.OR, Token.WORD);
+    assertEquals("{{'word1' AND 'word2'} OR 'word3'}", se.toString());
+    //word1 OR word2 AND word3
+    se = run(Token.WORD, Token.OR, Token.WORD, Token.AND, Token.WORD);
+    assertEquals("{'word1' OR {'word2' AND 'word3'}}", se.toString());
+  }
+
 
   private SearchExpression run(SearchQueryToken.Token... tokenArray) {
     List<SearchQueryToken> tokenList = prepareTokens(tokenArray);
-    tokens = tokenList.iterator();
-    SearchExpression se = processTokens();
+    SearchExpression se = parseInternal(tokenList);
     assertNotNull(se);
     return se;
   }