Disallow dollar sign in operator names, instead allow it as a non-first

character in identifiers.  The first change eliminates the current need
to put spaces around parameter references, as in "x<=$2".  The second
change improves compatibility with Oracle and some other RDBMSes.  This
was discussed and agreed to back in January, but did not get done.

src/backend/parser/scan.l

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/scan.l,v 1.107 2003/05/29 22:30:02 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/scan.l,v 1.108 2003/06/19 23:22:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -174,10 +174,10 @@ xcstop			\*+\/
 xcinside		[^*/]+
 
 digit			[0-9]
-letter			[\200-\377_A-Za-z]
-letter_or_digit	[\200-\377_A-Za-z0-9]
+ident_start		[A-Za-z\200-\377_]
+ident_cont		[A-Za-z\200-\377_0-9\$]
 
-identifier		{letter}{letter_or_digit}*
+identifier		{ident_start}{ident_cont}*
 
 typecast		"::"
 
@@ -191,8 +191,8 @@ typecast		"::"
  * If you change either set, adjust the character lists appearing in the
  * rule for "operator"!
  */
-self			[,()\[\].;$\:\+\-\*\/\%\^\<\>\=]
-op_chars		[\~\!\@\#\^\&\|\`\?\$\+\-\*\/\%\<\>\=]
+self			[,()\[\].;\:\+\-\*\/\%\^\<\>\=]
+op_chars		[\~\!\@\#\^\&\|\`\?\+\-\*\/\%\<\>\=]
 operator		{op_chars}+
 
 /* we no longer allow unary minus in numbers. 
@@ -461,7 +461,7 @@ other			.
 
 						for (ic = nchars-2; ic >= 0; ic--)
 						{
-							if (strchr("~!@#^&|`?$%", yytext[ic]))
+							if (strchr("~!@#^&|`?%", yytext[ic]))
 								break;
 						}
 						if (ic >= 0)
@@ -480,7 +480,7 @@ other			.
 						 * that the "self" rule would have.
 						 */
 						if (nchars == 1 &&
-							strchr(",()[].;$:+-*/%^<>=", yytext[0]))
+							strchr(",()[].;:+-*/%^<>=", yytext[0]))
 							return yytext[0];
 					}