[WIP] Prototype rewriting UNION ALL to disjunction

parser/grammar/sql-spec.txt

@@ -1123,7 +1123,7 @@ void numeric_primary():
   | character_value_expression()
 }
 
-void numeric_value_function() #FunctionCall:
+void numeric_value_function() #BuiltinFunctionCall(1):
 {}
 {
     position_expression()
@@ -1371,7 +1371,7 @@ void string_value_function():
   | binary_value_function()
 }
 
-void character_value_function() #FunctionCall:
+void character_value_function() #BuiltinFunctionCall:
 {}
 {
     character_substring_function()
@@ -1595,7 +1595,7 @@ void time_zone_specifier():
   | "TIME" "ZONE" interval_primary()
 }
 
-void datetime_value_function() #FunctionCall:
+void datetime_value_function() #BuiltinFunctionCall:
 {}
 {
     current_date_value_function()
@@ -1668,7 +1668,7 @@ void interval_primary():
 }
 
 
-void interval_value_function() #FunctionCall:
+void interval_value_function() #BuiltinFunctionCall:
 {}
 {
     interval_absolute_value_function()

parser/src/main/java/com/facebook/coresql/parser/AstNode.java

@@ -91,4 +91,9 @@ public String toString(String prefix)
         return super.toString(prefix) + " (" + getLocation().toString() + ")" +
                 (NumChildren() == 0 ? " (" + beginToken.image + ")" : "");
     }
+
+    public String GetSqlString()
+    {
+        return Unparser.unparseClean(this);
+    }
 }

parser/src/main/java/com/facebook/coresql/parser/Unparser.java

@@ -14,14 +14,15 @@
 package com.facebook.coresql.parser;
 
 import static com.facebook.coresql.parser.SqlParserConstants.EOF;
+import static com.facebook.coresql.parser.SqlParserConstants.tokenImage;
 
 public class Unparser
         extends com.facebook.coresql.parser.SqlParserDefaultVisitor
 {
     protected StringBuilder stringBuilder = new StringBuilder();
     private Token lastToken = new Token();
 
-    public static String unparse(AstNode node, Unparser unparser)
+    public static String unparseClean(AstNode node, Unparser unparser)
     {
         unparser.stringBuilder.setLength(0);
         unparser.lastToken.next = node.beginToken;
@@ -30,9 +31,9 @@ public static String unparse(AstNode node, Unparser unparser)
         return unparser.stringBuilder.toString();
     }
 
-    public static String unparse(AstNode node)
+    public static String unparseClean(AstNode node)
     {
-        return unparse(node, new Unparser());
+        return unparseClean(node, new Unparser());
     }
 
     private void printSpecialTokens(Token t)
@@ -62,6 +63,11 @@ public final void printToken(String s)
         stringBuilder.append(" " + s + " ");
     }
 
+    public final void printKeyword(int keyword)
+    {
+        printToken(tokenImage[keyword].substring(1, tokenImage[keyword].length() - 1));
+    }
+
     private void printToken(Token t)
     {
         while (lastToken != t) {

parser/src/test/java/com/facebook/coresql/parser/TestSqlParser.java

@@ -19,7 +19,7 @@
 import java.io.IOException;
 
 import static com.facebook.coresql.parser.ParserHelper.parseStatement;
-import static com.facebook.coresql.parser.Unparser.unparse;
+import static com.facebook.coresql.parser.Unparser.unparseClean;
 import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertNotNull;
 
@@ -66,7 +66,7 @@ public void parseUnparseTest()
         for (String sql : TEST_SQL_TESTSTRINGS) {
             AstNode ast = parse(sql);
             assertNotNull(ast);
-            assertEquals(sql.trim(), unparse(ast).trim());
+            assertEquals(sql.trim(), unparseClean(ast).trim());
         }
     }
 

parser/src/test/java/com/facebook/coresql/parser/sqllogictest/java/SqlLogicTest.java

@@ -34,7 +34,7 @@
 import java.util.Optional;
 
 import static com.facebook.coresql.parser.ParserHelper.parseStatement;
-import static com.facebook.coresql.parser.Unparser.unparse;
+import static com.facebook.coresql.parser.Unparser.unparseClean;
 import static com.facebook.coresql.parser.sqllogictest.java.SqlLogicTest.CoreSqlParsingError.PARSING_ERROR;
 import static com.facebook.coresql.parser.sqllogictest.java.SqlLogicTest.CoreSqlParsingError.UNPARSED_DOES_NOT_MATCH_ORIGINAL_ERROR;
 import static com.facebook.coresql.parser.sqllogictest.java.SqlLogicTest.CoreSqlParsingError.UNPARSING_ERROR;
@@ -132,7 +132,7 @@ private Optional<CoreSqlParsingError> checkStatementForParserError(String statem
         }
         String unparsed;
         try {
-            unparsed = unparse(ast.get());
+            unparsed = unparseClean(ast.get());
         }
         catch (Exception e) {
             return Optional.of(UNPARSING_ERROR);

rewriter/src/main/java/com/facebook/coresql/rewriter/OrderByRewriter.java

@@ -51,7 +51,7 @@ public Optional<RewriteResult> rewrite()
         if (patternMatchedNodes.isEmpty()) {
             return Optional.empty();
         }
-        String rewrittenSql = Unparser.unparse(root, this);
+        String rewrittenSql = Unparser.unparseClean(root, this);
         return Optional.of(new RewriteResult(REWRITE_NAME, rewrittenSql));
     }