Change parse-time representation of float literals (which include oversize

integers) to be strings instead of 'double'.  We convert from string form
to internal representation only after type resolution has determined the
correct type for the constant.  This eliminates loss-of-precision worries
and gets rid of the change in behavior seen at 17 digits with the
previous kluge.

1 files changed, 35 insertions, 26 deletions

diff --git a/src/backend/nodes/read.c b/src/backend/nodes/read.c
index 75e10576d5b..9f68f4d0e90 100644
--- a/src/backend/nodes/read.c
+++ b/src/backend/nodes/read.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/read.c,v 1.20 2000/01/26 05:56:32 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/read.c,v 1.21 2000/02/21 18:47:00 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -18,6 +18,7 @@
  *-------------------------------------------------------------------------
  */
 #include <ctype.h>
+#include <errno.h>
 
 #include "postgres.h"
 
@@ -193,30 +194,32 @@ static NodeTag
 nodeTokenType(char *token, int length)
 {
 	NodeTag		retval;
+	char	   *numptr;
+	int			numlen;
+	char	   *endptr;
 
 	/*
-	 * Check if the token is a number (decimal or integer, positive or
-	 * negative)
+	 * Check if the token is a number
 	 */
-	if (isdigit(*token) ||
-		(length >= 2 && *token == '-' && isdigit(token[1])))
+	numptr = token;
+	numlen = length;
+	if (*numptr == '+' || *numptr == '-')
+		numptr++, numlen--;
+	if ((numlen > 0 && isdigit(*numptr)) ||
+		(numlen > 1 && *numptr == '.' && isdigit(numptr[1])))
 	{
 		/*
-		 * skip the optional '-' (i.e. negative number)
+		 * Yes.  Figure out whether it is integral or float;
+		 * this requires both a syntax check and a range check.
+		 * strtol() can do both for us.
+		 * We know the token will end at a character that strtol will
+		 * stop at, so we do not need to modify the string.
 		 */
-		if (*token == '-')
-			token++, length--;
-
-		/*
-		 * See if there is a decimal point
-		 */
-		while (length > 0 && *token != '.')
-			token++, length--;
-
-		/*
-		 * if there isn't, token's an int, otherwise it's a float.
-		 */
-		retval = (*token != '.') ? T_Integer : T_Float;
+		errno = 0;
+		(void) strtol(token, &endptr, 10);
+		if (endptr != token+length || errno == ERANGE)
+			return T_Float;
+		return T_Integer;
 	}
 	/*
 	 * these three cases do not need length checks, since lsptok()
@@ -317,17 +320,23 @@ nodeRead(bool read_car_only)
 				make_dotted_pair_cell = true;
 			}
 			break;
-		case T_Float:
-			/* we know that the token terminates on a char atof will stop at */
-			this_value = (Node *) makeFloat(atof(token));
-			make_dotted_pair_cell = true;
-			break;
 		case T_Integer:
-			/* we know that the token terminates on a char atoi will stop at */
-			this_value = (Node *) makeInteger(atoi(token));
+			/* we know that the token terminates on a char atol will stop at */
+			this_value = (Node *) makeInteger(atol(token));
 			make_dotted_pair_cell = true;
 			break;
+		case T_Float:
+			{
+				char   *fval = (char *) palloc(tok_len + 1);
+
+				memcpy(fval, token, tok_len);
+				fval[tok_len] = '\0';
+				this_value = (Node *) makeFloat(fval);
+				make_dotted_pair_cell = true;
+			}
+			break;
 		case T_String:
+			/* need to remove leading and trailing quotes, and backslashes */
 			this_value = (Node *) makeString(debackslash(token+1, tok_len-2));
 			make_dotted_pair_cell = true;
 			break;