Hello
>
>
>> Other comments- I don't like using 'i' and 'j', you really should use
>> better variable names, especially in large loops which contain other
>> loops. I'd also suggest changing the outer loop to be equivilant to the
>> number of iterations that will be done instead of the number of items
>> and then to *not* update 'i' inside the inner-loop. That structure is
>> really just confusing, imv (I certainly didn't entirely follow what was
>> happening there the first time I read it). Isn't there a function you
>> could use to pull out the array slice you need on each iteration through
>> the array?
I looked on code again. There are a few results:
I'll change identifiers 'i' and 'j' with any, that you send. It's
usual identifiers for nested loops and in this case they has really
well known semantic - it's subscript of array.
But others changes are more difficult
we have to iterate over array's items because it allow seq. access to
array's data. I need a global index for function "array_get_isnull". I
can't to use a buildin functions like array_slize_size or
array_get_slice, because there is high overhead of array_seek
function. I redesigned the initial part of main cycle, but code is
little bit longer :(, but I hope, it is more readable.
Regards
Pavel
>>
>
> I don't know a better short index identifiers than I used. But I am
> not against to change.
>
> I'll try to redesign main cycle.
>
> Regards
>
> Pavel Stehule
>
>
>
>> Thanks,
>>
>> Stephen
>>
>> -----BEGIN PGP SIGNATURE-----
>> Version: GnuPG v1.4.10 (GNU/Linux)
>>
>> iEYEARECAAYFAk086MEACgkQrzgMPqB3kigCzQCffx0iVSMjU2UbOgAOaY/MvtOp
>> iKsAnA5tdhKxTssdXJ+Rda4qkhNVm26g
>> =Yn5O
>> -----END PGP SIGNATURE-----
>>
>>
>
*** ./gram.y.orig 2011-01-16 14:18:59.000000000 +0100
--- ./gram.y 2011-01-21 21:35:21.000000000 +0100
***************
*** 21,26 ****
--- 21,27 ----
#include "parser/parse_type.h"
#include "parser/scanner.h"
#include "parser/scansup.h"
+ #include "utils/array.h"
/* Location tracking support --- simpler than bison's default */
***************
*** 134,139 ****
--- 135,141 ----
PLpgSQL_datum *scalar;
PLpgSQL_rec *rec;
PLpgSQL_row *row;
+ int slice;
} forvariable;
struct
{
***************
*** 178,184 ****
%type <ival> assign_var
%type <var> cursor_variable
%type <datum> decl_cursor_arg
! %type <forvariable> for_variable
%type <stmt> for_control
%type <str> any_identifier opt_block_label opt_label
--- 180,186 ----
%type <ival> assign_var
%type <var> cursor_variable
%type <datum> decl_cursor_arg
! %type <forvariable> for_variable foreach_control
%type <stmt> for_control
%type <str> any_identifier opt_block_label opt_label
***************
*** 190,196 ****
%type <stmt> stmt_return stmt_raise stmt_execsql
%type <stmt> stmt_dynexecute stmt_for stmt_perform stmt_getdiag
%type <stmt> stmt_open stmt_fetch stmt_move stmt_close stmt_null
! %type <stmt> stmt_case
%type <list> proc_exceptions
%type <exception_block> exception_sect
--- 192,198 ----
%type <stmt> stmt_return stmt_raise stmt_execsql
%type <stmt> stmt_dynexecute stmt_for stmt_perform stmt_getdiag
%type <stmt> stmt_open stmt_fetch stmt_move stmt_close stmt_null
! %type <stmt> stmt_case stmt_foreach_a
%type <list> proc_exceptions
%type <exception_block> exception_sect
***************
*** 264,269 ****
--- 266,272 ----
%token <keyword> K_FETCH
%token <keyword> K_FIRST
%token <keyword> K_FOR
+ %token <keyword> K_FOREACH
%token <keyword> K_FORWARD
%token <keyword> K_FROM
%token <keyword> K_GET
***************
*** 298,303 ****
--- 301,307 ----
%token <keyword> K_ROWTYPE
%token <keyword> K_ROW_COUNT
%token <keyword> K_SCROLL
+ %token <keyword> K_SLICE
%token <keyword> K_SQLSTATE
%token <keyword> K_STRICT
%token <keyword> K_THEN
***************
*** 739,744 ****
--- 743,750 ----
{ $$ = $1; }
| stmt_for
{ $$ = $1; }
+ | stmt_foreach_a
+ { $$ = $1; }
| stmt_exit
{ $$ = $1; }
| stmt_return
***************
*** 1386,1391 ****
--- 1392,1455 ----
}
;
+ stmt_foreach_a : opt_block_label K_FOREACH foreach_control K_IN expr_until_loop loop_body
+ {
+ PLpgSQL_stmt_foreach_a *new = palloc0(sizeof(PLpgSQL_stmt_foreach_a));
+ new->cmd_type = PLPGSQL_STMT_FOREACH_A;
+ new->lineno = plpgsql_location_to_lineno(@2);
+ new->label = $1;
+ new->expr = $5;
+ new->slice = $3.slice;
+ new->body = $6.stmts;
+
+ if ($3.rec)
+ {
+ new->rec = $3.rec;
+ check_assignable((PLpgSQL_datum *) new->rec, @3);
+ }
+ else if ($3.row)
+ {
+ new->row = $3.row;
+ check_assignable((PLpgSQL_datum *) new->row, @3);
+ }
+ else if ($3.scalar)
+ {
+ Assert($3.scalar->dtype == PLPGSQL_DTYPE_VAR);
+ new->var = (PLpgSQL_var *) $3.scalar;
+ check_assignable($3.scalar, @3);
+
+ }
+ else
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("loop variable of loop over array must be a record, row variable, scalar variable or list of scalar variables"),
+ parser_errposition(@3)));
+ }
+
+ check_labels($1, $6.end_label, $6.end_label_location);
+ $$ = (PLpgSQL_stmt *) new;
+ }
+ ;
+
+ foreach_control : for_variable
+ {
+ $$ = $1;
+ $$.slice = 0;
+ }
+ | for_variable K_SLICE ICONST
+ {
+ $$ = $1;
+ $$.slice = $3;
+ if ($3 < 0 || $3 >= MAXDIM)
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("number of slicing array dimensions (%d) exceeds the maximum allowed (%d)",
+ $3, MAXDIM),
+ parser_errposition(@3)));
+ }
+ ;
+
stmt_exit : exit_type opt_label opt_exitcond
{
PLpgSQL_stmt_exit *new;
***************
*** 2063,2068 ****
--- 2127,2133 ----
| K_ROW_COUNT
| K_ROWTYPE
| K_SCROLL
+ | K_SLICE
| K_SQLSTATE
| K_TYPE
| K_USE_COLUMN
*** ./pl_exec.c.orig 2011-01-16 14:18:59.000000000 +0100
--- ./pl_exec.c 2011-01-24 12:05:58.599741965 +0100
***************
*** 107,112 ****
--- 107,114 ----
PLpgSQL_stmt_fors *stmt);
static int exec_stmt_forc(PLpgSQL_execstate *estate,
PLpgSQL_stmt_forc *stmt);
+ static int exec_stmt_foreach_a(PLpgSQL_execstate *estate,
+ PLpgSQL_stmt_foreach_a *stmt);
static int exec_stmt_open(PLpgSQL_execstate *estate,
PLpgSQL_stmt_open *stmt);
static int exec_stmt_fetch(PLpgSQL_execstate *estate,
***************
*** 1312,1317 ****
--- 1314,1323 ----
rc = exec_stmt_forc(estate, (PLpgSQL_stmt_forc *) stmt);
break;
+ case PLPGSQL_STMT_FOREACH_A:
+ rc = exec_stmt_foreach_a(estate, (PLpgSQL_stmt_foreach_a *) stmt);
+ break;
+
case PLPGSQL_STMT_EXIT:
rc = exec_stmt_exit(estate, (PLpgSQL_stmt_exit *) stmt);
break;
***************
*** 2028,2033 ****
--- 2034,2295 ----
/* ----------
+ * exec_stmt_foreach_a Implements loop over array
+ *
+ * ----------
+ */
+ static int
+ exec_stmt_foreach_a(PLpgSQL_execstate *estate, PLpgSQL_stmt_foreach_a *stmt)
+ {
+ Datum value;
+ bool isnull;
+ Oid valtype;
+ int nitems;
+ int slice_len = 0; /* be compiler quite */
+ Oid array_typelem;
+ int i;
+ ArrayType *arr;
+ char *ptr;
+ bits8 *arraynullsptr;
+ int16 elmlen;
+ bool elmbyval;
+ char elmalign;
+ PLpgSQL_datum *ctrl_var = NULL; /* be compiler quite */
+ bool found = false;
+ int rc = PLPGSQL_RC_OK;
+ int niterations;
+ int offset;
+
+ /* get the value of the array expression using array_expr */
+ value = exec_eval_expr(estate, stmt->expr, &isnull, &valtype);
+ if (isnull)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("NULL value isn't allowed as parameter of FOREACH-IN")));
+
+ /* check the type of the expression - must be an array */
+ array_typelem = get_element_type(valtype);
+
+ if (!OidIsValid(array_typelem))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("result of expression isn't an array"),
+ errdetail("result of expression is %s",
+ format_type_be(valtype))));
+
+ /* make a copy of the result */
+ arr = DatumGetArrayTypePCopy(value);
+
+ /* Calculate the number of elements we're going to loop through */
+ nitems = ArrayGetNItems(ARR_NDIM(arr), ARR_DIMS(arr));
+
+ /* Gather information about the array */
+ ptr = ARR_DATA_PTR(arr);
+ arraynullsptr = ARR_NULLBITMAP(arr);
+ get_typlenbyvalalign(ARR_ELEMTYPE(arr),
+ &elmlen,
+ &elmbyval,
+ &elmalign);
+
+ /* Clean up any leftover temporary memory */
+ exec_eval_cleanup(estate);
+
+ /* slice dimension should be less or equal to array dimension */
+ if (stmt->slice > ARR_NDIM(arr))
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("slice level %d is higher than array dimension",
+ stmt->slice)));
+
+ /*
+ * If the target needs to be an array, check that it actually is,
+ * and that it has a valid dimension for the array we're looping
+ * through.
+ */
+ if (stmt->slice > 0)
+ {
+ if (stmt->var != NULL)
+ {
+ int typoid = stmt->var->datatype->typoid;
+ int elmoid = get_element_type(typoid);
+
+ /* target variable has to be an array */
+ if (elmoid == InvalidOid)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("target variable \"%s\" for sliced array should be an array type",
+ stmt->var->refname),
+ errhint("Value assigned will be of an array type.")));
+ /* Determine the number of items in the slice */
+ slice_len = ArrayGetNItems(stmt->slice, ARR_DIMS(arr) + ARR_NDIM(arr) - stmt->slice);
+ ctrl_var = estate->datums[stmt->var->dno];
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("target variable \"%s\" for sliced array should be an array type",
+ stmt->row ? stmt->row->refname : stmt->rec->refname),
+ errhint("Value assigned will be of an array type.")));
+
+ niterations = nitems / slice_len;
+ }
+ else
+ {
+ /* target variable has to be a scalar */
+ if (stmt->var != NULL)
+ {
+ int typoid = stmt->var->datatype->typoid;
+ int elmoid = get_element_type(typoid);
+
+ /* target variable should be a scalar */
+ if (elmoid != InvalidOid)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("target variable \"%s\" is an array",
+ stmt->var->refname),
+ errhint("Value assigned will be of a scalar type")));
+
+ ctrl_var = estate->datums[stmt->var->dno];
+ }
+ else if (stmt->row != NULL)
+ {
+ ctrl_var = estate->datums[stmt->row->dno];
+ }
+ else
+ {
+ ctrl_var = estate->datums[stmt->rec->dno];
+ }
+
+ niterations = nitems;
+ }
+
+ /*
+ * main loop - iteration over array's items or array's slices
+ */
+ offset = 0;
+ for (i = 0; i < niterations; i++)
+ {
+ /*
+ * Set a target variable. Construct an subarray (slice) when it is requested.
+ * When slice isn't requested, then target type is same as array element type,
+ * otherwise target type is same as original array.
+ */
+ if (stmt->slice > 0)
+ {
+ int j;
+ ArrayBuildState *astate = NULL;
+ Datum slice;
+
+ for (j = 0; j < slice_len; j++)
+ {
+ if (array_get_isnull(arraynullsptr, offset++))
+ {
+ isnull = true;
+ value = (Datum) 0;
+ }
+ else
+ {
+ isnull = false;
+ value = fetch_att(ptr, elmbyval, elmlen);
+ ptr = att_addlength_pointer(ptr, elmlen, ptr);
+ ptr = (char *) att_align_nominal(ptr, elmalign);
+ }
+ astate = accumArrayResult(astate, value, isnull,
+ array_typelem,
+ CurrentMemoryContext);
+ }
+ isnull = false;
+ slice = makeMdArrayResult(astate, stmt->slice,
+ ARR_DIMS(arr) + ARR_NDIM(arr) - stmt->slice,
+ ARR_LBOUND(arr) ? ARR_LBOUND(arr) + ARR_NDIM(arr) - stmt->slice : NULL,
+ CurrentMemoryContext, true);
+ exec_assign_value(estate, ctrl_var, slice, valtype, &isnull);
+ }
+ else
+ {
+ /* get a value */
+ if (array_get_isnull(arraynullsptr, offset++))
+ {
+ isnull = true;
+ value = (Datum) 0;
+ }
+ else
+ {
+ isnull = false;
+ value = fetch_att(ptr, elmbyval, elmlen);
+
+ ptr = att_addlength_pointer(ptr, elmlen, ptr);
+ ptr = (char *) att_align_nominal(ptr, elmalign);
+ }
+ exec_assign_value(estate, ctrl_var, value, array_typelem, &isnull);
+ }
+
+ /*
+ * Execute the statements
+ */
+ rc = exec_stmts(estate, stmt->body);
+
+ if (rc == PLPGSQL_RC_RETURN)
+ break; /* break out of the loop */
+ else if (rc == PLPGSQL_RC_EXIT)
+ {
+ if (estate->exitlabel == NULL)
+ /* unlabelled exit, finish the current loop */
+ rc = PLPGSQL_RC_OK;
+ else if (stmt->label != NULL &&
+ strcmp(stmt->label, estate->exitlabel) == 0)
+ {
+ /* labelled exit, matches the current stmt's label */
+ estate->exitlabel = NULL;
+ rc = PLPGSQL_RC_OK;
+ }
+
+ /*
+ * otherwise, this is a labelled exit that does not match the
+ * current statement's label, if any: return RC_EXIT so that the
+ * EXIT continues to propagate up the stack.
+ */
+ break;
+ }
+ else if (rc == PLPGSQL_RC_CONTINUE)
+ {
+ if (estate->exitlabel == NULL)
+ /* unlabelled continue, so re-run the current loop */
+ rc = PLPGSQL_RC_OK;
+ else if (stmt->label != NULL &&
+ strcmp(stmt->label, estate->exitlabel) == 0)
+ {
+ /* label matches named continue, so re-run loop */
+ estate->exitlabel = NULL;
+ rc = PLPGSQL_RC_OK;
+ }
+ else
+ {
+ /*
+ * otherwise, this is a named continue that does not match the
+ * current statement's label, if any: return RC_CONTINUE so
+ * that the CONTINUE will propagate up the stack.
+ */
+ break;
+ }
+ }
+ }
+
+ pfree(arr);
+
+ /*
+ * Set the FOUND variable to indicate the result of executing the loop
+ * (namely, whether we looped one or more times). This must be set here so
+ * that it does not interfere with the value of the FOUND variable inside
+ * the loop processing itself.
+ */
+ exec_set_found(estate, found);
+
+ return rc;
+ }
+
+
+ /* ----------
* exec_stmt_exit Implements EXIT and CONTINUE
*
* This begins the process of exiting / restarting a loop.
***************
*** 3179,3185 ****
SPI_cursor_close(portal);
return rc;
! }
/* ----------
--- 3441,3447 ----
SPI_cursor_close(portal);
return rc;
! }
/* ----------
*** ./pl_funcs.c.orig 2011-01-16 14:18:59.000000000 +0100
--- ./pl_funcs.c 2011-01-21 22:55:19.000000000 +0100
***************
*** 230,235 ****
--- 230,237 ----
return _("FOR over SELECT rows");
case PLPGSQL_STMT_FORC:
return _("FOR over cursor");
+ case PLPGSQL_STMT_FOREACH_A:
+ return _("FOREACH over array");
case PLPGSQL_STMT_EXIT:
return "EXIT";
case PLPGSQL_STMT_RETURN:
***************
*** 293,298 ****
--- 295,301 ----
static void dump_close(PLpgSQL_stmt_close *stmt);
static void dump_perform(PLpgSQL_stmt_perform *stmt);
static void dump_expr(PLpgSQL_expr *expr);
+ static void dump_foreach_a(PLpgSQL_stmt_foreach_a *stmt);
static void
***************
*** 376,381 ****
--- 379,387 ----
case PLPGSQL_STMT_PERFORM:
dump_perform((PLpgSQL_stmt_perform *) stmt);
break;
+ case PLPGSQL_STMT_FOREACH_A:
+ dump_foreach_a((PLpgSQL_stmt_foreach_a *) stmt);
+ break;
default:
elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
break;
***************
*** 596,601 ****
--- 602,625 ----
}
static void
+ dump_foreach_a(PLpgSQL_stmt_foreach_a *stmt)
+ {
+ dump_ind();
+ printf("FOREACHA %s", (stmt->rec != NULL) ? stmt->rec->refname :
+ (stmt->row != NULL) ? stmt->row->refname : stmt->var->refname);
+ if (stmt->slice != 0)
+ printf("SLICE %d ", stmt->slice);
+ printf("IN ");
+ dump_expr(stmt->expr);
+ printf("\n");
+
+ dump_stmts(stmt->body);
+
+ dump_ind();
+ printf(" ENDOFOREACHA");
+ }
+
+ static void
dump_open(PLpgSQL_stmt_open *stmt)
{
dump_ind();
*** ./plpgsql.h.orig 2011-01-16 14:18:59.000000000 +0100
--- ./plpgsql.h 2011-01-21 22:56:26.000000000 +0100
***************
*** 87,92 ****
--- 87,93 ----
PLPGSQL_STMT_CASE,
PLPGSQL_STMT_LOOP,
PLPGSQL_STMT_WHILE,
+ PLPGSQL_STMT_FOREACH_A,
PLPGSQL_STMT_FORI,
PLPGSQL_STMT_FORS,
PLPGSQL_STMT_FORC,
***************
*** 427,432 ****
--- 428,447 ----
typedef struct
+ { /* FOREACH item in array loop */
+ int cmd_type;
+ int lineno;
+ char *label;
+ PLpgSQL_var *var;
+ PLpgSQL_rec *rec;
+ PLpgSQL_row *row;
+ PLpgSQL_expr *expr;
+ int slice;
+ List *body; /* List of statements */
+ } PLpgSQL_stmt_foreach_a;
+
+
+ typedef struct
{ /* FOR statement with integer loopvar */
int cmd_type;
int lineno;
*** ./pl_scanner.c.orig 2011-01-16 14:18:59.000000000 +0100
--- ./pl_scanner.c 2011-01-17 11:31:54.000000000 +0100
***************
*** 77,82 ****
--- 77,83 ----
PG_KEYWORD("exit", K_EXIT, RESERVED_KEYWORD)
PG_KEYWORD("fetch", K_FETCH, RESERVED_KEYWORD)
PG_KEYWORD("for", K_FOR, RESERVED_KEYWORD)
+ PG_KEYWORD("foreach", K_FOREACH, RESERVED_KEYWORD)
PG_KEYWORD("from", K_FROM, RESERVED_KEYWORD)
PG_KEYWORD("get", K_GET, RESERVED_KEYWORD)
PG_KEYWORD("if", K_IF, RESERVED_KEYWORD)
***************
*** 133,138 ****
--- 134,140 ----
PG_KEYWORD("row_count", K_ROW_COUNT, UNRESERVED_KEYWORD)
PG_KEYWORD("rowtype", K_ROWTYPE, UNRESERVED_KEYWORD)
PG_KEYWORD("scroll", K_SCROLL, UNRESERVED_KEYWORD)
+ PG_KEYWORD("slice", K_SLICE, UNRESERVED_KEYWORD)
PG_KEYWORD("sqlstate", K_SQLSTATE, UNRESERVED_KEYWORD)
PG_KEYWORD("type", K_TYPE, UNRESERVED_KEYWORD)
PG_KEYWORD("use_column", K_USE_COLUMN, UNRESERVED_KEYWORD)
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