Convert contrib/isn's input functions to report errors softly

contrib/isn/expected/isn.out

@@ -260,6 +260,21 @@ SELECT '12345679'::ISSN = '9771234567003'::EAN13 AS "ok",
  t  | t  | t
 (1 row)
 
+-- test non-error-throwing input API
+SELECT str as isn, typ as "type",
+       pg_input_is_valid(str,typ) as ok,
+       pg_input_error_message(str,typ) as errmsg
+FROM (VALUES ('9780123456786', 'UPC'),
+             ('postgresql...','EAN13'),
+             ('9771234567003','ISSN'))
+      AS a(str,typ);
+      isn      | type  | ok |                         errmsg                         
+---------------+-------+----+--------------------------------------------------------
+ 9780123456786 | UPC   | f  | cannot cast ISBN to UPC for number: "9780123456786"
+ postgresql... | EAN13 | f  | invalid input syntax for EAN13 number: "postgresql..."
+ 9771234567003 | ISSN  | t  | 
+(3 rows)
+
 --
 -- cleanup
 --

contrib/isn/isn.c

@@ -675,14 +675,14 @@ eantoobig:
 /*
  * string2ean --- try to parse a string into an ean13.
  *
- * If errorOK is false, ereport a useful error message if the string is bad.
+ * ereturn false with a useful error message if the string is bad.
- * If errorOK is true, just return "false" for bad input.
+ * Otherwise return true.
  *
  * if the input string ends with '!' it will always be treated as invalid
  * (even if the check digit is valid)
  */
 static bool
-string2ean(const char *str, bool errorOK, ean13 *result,
+string2ean(const char *str, struct Node *escontext, ean13 *result,
 		   enum isn_type accept)
 {
 	bool		digit,
@@ -876,48 +876,38 @@ eanbadcheck:
 		return true;
 	}
 
-	if (!errorOK)
-	{
 	if (rcheck == (unsigned) -1)
 	{
-			ereport(ERROR,
+		ereturn(escontext, false,
 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 				 errmsg("invalid %s number: \"%s\"",
 						isn_names[accept], str)));
 	}
 	else
 	{
-			ereport(ERROR,
+		ereturn(escontext, false,
 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 				 errmsg("invalid check digit for %s number: \"%s\", should be %c",
 						isn_names[accept], str, (rcheck == 10) ? ('X') : (rcheck + '0'))));
 	}
-	}
-	return false;
 
 eaninvalid:
-	if (!errorOK)
+	ereturn(escontext, false,
-		ereport(ERROR,
 			(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 			 errmsg("invalid input syntax for %s number: \"%s\"",
 					isn_names[accept], str)));
-	return false;
 
 eanwrongtype:
-	if (!errorOK)
+	ereturn(escontext, false,
-		ereport(ERROR,
 			(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 			 errmsg("cannot cast %s to %s for number: \"%s\"",
 					isn_names[type], isn_names[accept], str)));
-	return false;
 
 eantoobig:
-	if (!errorOK)
+	ereturn(escontext, false,
-		ereport(ERROR,
 			(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 			 errmsg("value \"%s\" is out of range for %s type",
 					str, isn_names[accept])));
-	return false;
 }
 
 /*----------------------------------------------------------
@@ -952,7 +942,7 @@ isn_out(PG_FUNCTION_ARGS)
 	char	   *result;
 	char		buf[MAXEAN13LEN + 1];
 
-	(void) ean2string(val, false, buf, true);
+	(void) ean2string(val, fcinfo->context, buf, true);
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -968,7 +958,7 @@ ean13_out(PG_FUNCTION_ARGS)
 	char	   *result;
 	char		buf[MAXEAN13LEN + 1];
 
-	(void) ean2string(val, false, buf, false);
+	(void) ean2string(val, fcinfo->context, buf, false);
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -983,7 +973,8 @@ ean13_in(PG_FUNCTION_ARGS)
 	const char *str = PG_GETARG_CSTRING(0);
 	ean13		result;
 
-	(void) string2ean(str, false, &result, EAN13);
+	if (!string2ean(str, fcinfo->context, &result, EAN13))
+		PG_RETURN_NULL();
 	PG_RETURN_EAN13(result);
 }
 
@@ -996,7 +987,8 @@ isbn_in(PG_FUNCTION_ARGS)
 	const char *str = PG_GETARG_CSTRING(0);
 	ean13		result;
 
-	(void) string2ean(str, false, &result, ISBN);
+	if (!string2ean(str, fcinfo->context, &result, ISBN))
+		PG_RETURN_NULL();
 	PG_RETURN_EAN13(result);
 }
 
@@ -1009,7 +1001,8 @@ ismn_in(PG_FUNCTION_ARGS)
 	const char *str = PG_GETARG_CSTRING(0);
 	ean13		result;
 
-	(void) string2ean(str, false, &result, ISMN);
+	if (!string2ean(str, fcinfo->context, &result, ISMN))
+		PG_RETURN_NULL();
 	PG_RETURN_EAN13(result);
 }
 
@@ -1022,7 +1015,8 @@ issn_in(PG_FUNCTION_ARGS)
 	const char *str = PG_GETARG_CSTRING(0);
 	ean13		result;
 
-	(void) string2ean(str, false, &result, ISSN);
+	if (!string2ean(str, fcinfo->context, &result, ISSN))
+		PG_RETURN_NULL();
 	PG_RETURN_EAN13(result);
 }
 
@@ -1035,7 +1029,8 @@ upc_in(PG_FUNCTION_ARGS)
 	const char *str = PG_GETARG_CSTRING(0);
 	ean13		result;
 
-	(void) string2ean(str, false, &result, UPC);
+	if (!string2ean(str, fcinfo->context, &result, UPC))
+		PG_RETURN_NULL();
 	PG_RETURN_EAN13(result);
 }
 

contrib/isn/sql/isn.sql

@@ -107,6 +107,15 @@ SELECT '12345679'::ISSN = '9771234567003'::EAN13 AS "ok",
        'M-1234-5678-5'::ISMN = '9790123456785'::EAN13 AS "ok",
        '9791234567896'::EAN13 != '123456789X'::ISBN AS "nope";
 
+-- test non-error-throwing input API
+SELECT str as isn, typ as "type",
+       pg_input_is_valid(str,typ) as ok,
+       pg_input_error_message(str,typ) as errmsg
+FROM (VALUES ('9780123456786', 'UPC'),
+             ('postgresql...','EAN13'),
+             ('9771234567003','ISSN'))
+      AS a(str,typ);
+
 --
 -- cleanup
 --