Clean up grammar a bit
Simplify the grammar specification of substring() and overlay() a bit, simplify and update some comments. Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Reviewed-by: Vik Fearing <vik@postgresfriends.org> Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr> Discussion: https://www.postgresql.org/message-id/flat/a15db31c-d0f8-8ce0-9039-578a31758adb%402ndquadrant.com
This commit is contained in:
Peter Eisentraut
parent
68de1440c7
commit
aafefb4dcb
|
|
@ -452,7 +452,6 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
|
|||
%type <list> extract_list overlay_list position_list
|
||||
%type <list> substr_list trim_list
|
||||
%type <list> opt_interval interval_second
|
||||
%type <node> overlay_placing substr_from substr_for
|
||||
%type <str> unicode_normal_form
|
||||
|
||||
%type <boolean> opt_instead
|
||||
|
|
@ -13797,11 +13796,6 @@ func_expr_common_subexpr:
|
|||
}
|
||||
| OVERLAY '(' overlay_list ')'
|
||||
{
|
||||
/* overlay(A PLACING B FROM C FOR D) is converted to
|
||||
* overlay(A, B, C, D)
|
||||
* overlay(A PLACING B FROM C) is converted to
|
||||
* overlay(A, B, C)
|
||||
*/
|
||||
$$ = (Node *) makeFuncCall(SystemFuncName("overlay"), $3, @1);
|
||||
}
|
||||
| POSITION '(' position_list ')'
|
||||
|
|
@ -14437,63 +14431,45 @@ unicode_normal_form:
|
|||
| NFKD { $$ = "nfkd"; }
|
||||
;
|
||||
|
||||
/* OVERLAY() arguments
|
||||
* SQL99 defines the OVERLAY() function:
|
||||
* o overlay(text placing text from int for int)
|
||||
* o overlay(text placing text from int)
|
||||
* and similarly for binary strings
|
||||
*/
|
||||
/* OVERLAY() arguments */
|
||||
overlay_list:
|
||||
a_expr overlay_placing substr_from substr_for
|
||||
a_expr PLACING a_expr FROM a_expr FOR a_expr
|
||||
{
|
||||
$$ = list_make4($1, $2, $3, $4);
|
||||
/* overlay(A PLACING B FROM C FOR D) is converted to overlay(A, B, C, D) */
|
||||
$$ = list_make4($1, $3, $5, $7);
|
||||
}
|
||||
| a_expr overlay_placing substr_from
|
||||
| a_expr PLACING a_expr FROM a_expr
|
||||
{
|
||||
$$ = list_make3($1, $2, $3);
|
||||
/* overlay(A PLACING B FROM C) is converted to overlay(A, B, C) */
|
||||
$$ = list_make3($1, $3, $5);
|
||||
}
|
||||
;
|
||||
|
||||
overlay_placing:
|
||||
PLACING a_expr
|
||||
{ $$ = $2; }
|
||||
;
|
||||
|
||||
/* position_list uses b_expr not a_expr to avoid conflict with general IN */
|
||||
|
||||
position_list:
|
||||
b_expr IN_P b_expr { $$ = list_make2($3, $1); }
|
||||
| /*EMPTY*/ { $$ = NIL; }
|
||||
;
|
||||
|
||||
/* SUBSTRING() arguments
|
||||
* SQL9x defines a specific syntax for arguments to SUBSTRING():
|
||||
* o substring(text from int for int)
|
||||
* o substring(text from int) get entire string from starting point "int"
|
||||
* o substring(text for int) get first "int" characters of string
|
||||
* o substring(text from pattern) get entire string matching pattern
|
||||
* o substring(text from pattern for escape) same with specified escape char
|
||||
* We also want to support generic substring functions which accept
|
||||
* the usual generic list of arguments. So we will accept both styles
|
||||
* here, and convert the SQL9x style to the generic list for further
|
||||
* processing. - thomas 2000-11-28
|
||||
*/
|
||||
/* SUBSTRING() arguments */
|
||||
substr_list:
|
||||
a_expr substr_from substr_for
|
||||
a_expr FROM a_expr FOR a_expr
|
||||
{
|
||||
$$ = list_make3($1, $2, $3);
|
||||
$$ = list_make3($1, $3, $5);
|
||||
}
|
||||
| a_expr substr_for substr_from
|
||||
| a_expr FOR a_expr FROM a_expr
|
||||
{
|
||||
/* not legal per SQL99, but might as well allow it */
|
||||
$$ = list_make3($1, $3, $2);
|
||||
/* not legal per SQL, but might as well allow it */
|
||||
$$ = list_make3($1, $5, $3);
|
||||
}
|
||||
| a_expr substr_from
|
||||
| a_expr FROM a_expr
|
||||
{
|
||||
$$ = list_make2($1, $2);
|
||||
$$ = list_make2($1, $3);
|
||||
}
|
||||
| a_expr substr_for
|
||||
| a_expr FOR a_expr
|
||||
{
|
||||
/* not legal per SQL */
|
||||
|
||||
/*
|
||||
* Since there are no cases where this syntax allows
|
||||
* a textual FOR value, we forcibly cast the argument
|
||||
|
|
@ -14504,9 +14480,13 @@ substr_list:
|
|||
* is unknown or doesn't have an implicit cast to int4.
|
||||
*/
|
||||
$$ = list_make3($1, makeIntConst(1, -1),
|
||||
makeTypeCast($2,
|
||||
makeTypeCast($3,
|
||||
SystemTypeName("int4"), -1));
|
||||
}
|
||||
/*
|
||||
* We also want to support generic substring functions that
|
||||
* accept the usual generic list of arguments.
|
||||
*/
|
||||
| expr_list
|
||||
{
|
||||
$$ = $1;
|
||||
|
|
@ -14515,13 +14495,6 @@ substr_list:
|
|||
{ $$ = NIL; }
|
||||
;
|
||||
|
||||
substr_from:
|
||||
FROM a_expr { $$ = $2; }
|
||||
;
|
||||
|
||||
substr_for: FOR a_expr { $$ = $2; }
|
||||
;
|
||||
|
||||
trim_list: a_expr FROM expr_list { $$ = lappend($3, $1); }
|
||||
| FROM expr_list { $$ = $2; }
|
||||
| expr_list { $$ = $1; }
|
||||
|
|
|
|||
Loading…
Reference in New Issue