Tweak scanner/grammar interface so that the keyword-as-identifier rules

in gram.y can make use of the keywords.c string table, instead of having
their own copies of the keyword strings.  This saves a few kilobytes and
more importantly eliminates an opportunity for cut-and-paste errors.

src/backend/parser/keywords.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.107 2002/04/21 19:21:49 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.108 2002/05/02 18:44:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -26,7 +26,7 @@
  * !!WARNING!!: This list must be sorted, because binary
  *		 search is used to locate entries.
  */
-static ScanKeyword ScanKeywords[] = {
+static const ScanKeyword ScanKeywords[] = {
 	/* name, value */
 	{"abort", ABORT_TRANS},
 	{"absolute", ABSOLUTE},
@@ -303,14 +303,14 @@ static ScanKeyword ScanKeywords[] = {
  * keywords are to be matched in this way even though non-keyword identifiers
  * receive a different case-normalization mapping.
  */
-ScanKeyword *
-ScanKeywordLookup(char *text)
+const ScanKeyword *
+ScanKeywordLookup(const char *text)
 {
 	int			len,
 				i;
 	char		word[NAMEDATALEN];
-	ScanKeyword *low;
-	ScanKeyword *high;
+	const ScanKeyword *low;
+	const ScanKeyword *high;
 
 	len = strlen(text);
 	/* We assume all keywords are shorter than NAMEDATALEN. */
@@ -342,7 +342,7 @@ ScanKeywordLookup(char *text)
 	high = endof(ScanKeywords) - 1;
 	while (low <= high)
 	{
-		ScanKeyword *middle;
+		const ScanKeyword *middle;
 		int			difference;
 
 		middle = low + (high - low) / 2;

src/backend/parser/scan.l

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/scan.l,v 1.93 2002/05/01 17:12:07 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/scan.l,v 1.94 2002/05/02 18:44:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -504,14 +504,17 @@ other			.
 
 
 {identifier}	{
-					ScanKeyword	   *keyword;
+					const ScanKeyword *keyword;
 					char		   *ident;
 					int				i;
 
 					/* Is it a keyword? */
 					keyword = ScanKeywordLookup(yytext);
 					if (keyword != NULL)
+					{
+						yylval.keyword = keyword->name;
 						return keyword->value;
+					}
 
 					/*
 					 * No.  Convert the identifier to lower case, and truncate

src/backend/utils/adt/ruleutils.c

@@ -3,7 +3,7 @@
  *				back to source text
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.100 2002/04/28 00:49:13 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.101 2002/05/02 18:44:11 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -2611,7 +2611,7 @@ quote_identifier(const char *ident)
 		 * Note: ScanKeywordLookup() does case-insensitive comparison, but
 		 * that's fine, since we already know we have all-lower-case.
 		 */
-		if (ScanKeywordLookup((char *) ident) != NULL)
+		if (ScanKeywordLookup(ident) != NULL)
 			safe = false;
 	}
 

src/include/parser/keywords.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: keywords.h,v 1.14 2002/04/21 00:26:44 tgl Exp $
+ * $Id: keywords.h,v 1.15 2002/05/02 18:44:11 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,10 +16,10 @@
 
 typedef struct ScanKeyword
 {
-	char	   *name;
+	const char *name;
 	int			value;
 } ScanKeyword;
 
-extern ScanKeyword *ScanKeywordLookup(char *text);
+extern const ScanKeyword *ScanKeywordLookup(const char *text);
 
 #endif   /* KEYWORDS_H */