Get rid of long-since-vestigial Iter node type, in favor of adding a

returns-set boolean field in Func and Oper nodes.  This allows cleaner,
more reliable tests for expressions returning sets in the planner and
parser.  For example, a WHERE clause returning a set is now detected
and complained of in the parser, not only at runtime.

8 files changed, 54 insertions, 105 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 3120fb5fae0..ca61cb51a76 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: catversion.h,v 1.130 2002/05/12 20:10:04 tgl Exp $
+ * $Id: catversion.h,v 1.131 2002/05/12 23:43:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200205121
+#define CATALOG_VERSION_NO	200205122
 
 #endif
diff --git a/src/include/executor/execFlatten.h b/src/include/executor/execFlatten.h
deleted file mode 100644
index 1795ed1c487..00000000000
--- a/src/include/executor/execFlatten.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * execFlatten.h
- *	  prototypes for execFlatten.c.
- *
- *
- * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * $Id: execFlatten.h,v 1.16 2001/11/05 17:46:33 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-#ifndef EXECFLATTEN_H
-#define EXECFLATTEN_H
-
-#include "nodes/execnodes.h"
-#include "nodes/parsenodes.h"
-
-
-extern Datum ExecEvalIter(Iter *iterNode, ExprContext *econtext,
-			 bool *isNull, ExprDoneCond *isDone);
-
-extern void ExecEvalFjoin(TargetEntry *tlist, ExprContext *econtext,
-			  bool *isNullVect, ExprDoneCond *fj_isDone);
-
-#endif   /* EXECFLATTEN_H */
diff --git a/src/include/nodes/makefuncs.h b/src/include/nodes/makefuncs.h
index 4096c2d9fb3..e3b6a164377 100644
--- a/src/include/nodes/makefuncs.h
+++ b/src/include/nodes/makefuncs.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: makefuncs.h,v 1.35 2002/04/16 23:08:12 tgl Exp $
+ * $Id: makefuncs.h,v 1.36 2002/05/12 23:43:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,8 +22,9 @@ extern A_Expr *makeSimpleA_Expr(int oper, const char *name,
 								Node *lexpr, Node *rexpr);
 
 extern Oper *makeOper(Oid opno,
-		 Oid opid,
-		 Oid opresulttype);
+					  Oid opid,
+					  Oid opresulttype,
+					  bool opretset);
 
 extern Var *makeVar(Index varno,
 		AttrNumber varattno,
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 492619e194d..7de647d1362 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodes.h,v 1.106 2002/05/12 20:10:04 tgl Exp $
+ * $Id: nodes.h,v 1.107 2002/05/12 23:43:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -66,7 +66,6 @@ typedef enum NodeTag
 	T_Func,
 	T_FieldSelect,
 	T_ArrayRef,
-	T_Iter,
 	T_RelabelType,
 	T_RangeTblRef,
 	T_FromExpr,
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 6eed89a7042..342ac11bb5b 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: primnodes.h,v 1.62 2002/05/12 20:10:05 tgl Exp $
+ * $Id: primnodes.h,v 1.63 2002/05/12 23:43:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -151,13 +151,52 @@ typedef struct Expr
 {
 	NodeTag		type;
 	Oid			typeOid;		/* oid of the type of this expression */
-	OpType		opType;			/* type of this expression */
+	OpType		opType;			/* kind of expression */
 	Node	   *oper;			/* operator node if needed (Oper, Func, or
 								 * SubPlan) */
 	List	   *args;			/* arguments to this expression */
 } Expr;
 
 /*
+ * Oper - Expr subnode for an OP_EXPR
+ *
+ * NOTE: in the good old days 'opno' used to be both (or either, or
+ * neither) the pg_operator oid, and/or the pg_proc oid depending
+ * on the postgres module in question (parser->pg_operator,
+ * executor->pg_proc, planner->both), the mood of the programmer,
+ * and the phase of the moon (rumors that it was also depending on the day
+ * of the week are probably false). To make things even more postgres-like
+ * (i.e. a mess) some comments were referring to 'opno' using the name
+ * 'opid'. Anyway, now we have two separate fields, and of course that
+ * immediately removes all bugs from the code...		[ sp :-) ].
+ *
+ * Note also that opid is not necessarily filled in immediately on creation
+ * of the node.  The planner makes sure it is valid before passing the node
+ * tree to the executor, but during parsing/planning opid is typically 0.
+ */
+typedef struct Oper
+{
+	NodeTag		type;
+	Oid			opno;			/* PG_OPERATOR OID of the operator */
+	Oid			opid;			/* PG_PROC OID of underlying function */
+	Oid			opresulttype;	/* PG_TYPE OID of result value */
+	bool		opretset;		/* true if operator returns set */
+	FunctionCachePtr op_fcache;	/* runtime state, else NULL */
+} Oper;
+
+/*
+ * Func - Expr subnode for a FUNC_EXPR
+ */
+typedef struct Func
+{
+	NodeTag		type;
+	Oid			funcid;			/* PG_PROC OID of the function */
+	Oid			funcresulttype;	/* PG_TYPE OID of result value */
+	bool		funcretset;		/* true if function returns set */
+	FunctionCachePtr func_fcache; /* runtime state, or NULL */
+} Func;
+
+/*
  * Var
  *
  * Note: during parsing/planning, varnoold/varoattno are always just copies
@@ -196,37 +235,6 @@ typedef struct Var
 	AttrNumber	varoattno;		/* original value of varattno */
 } Var;
 
-/*--------------------
- * Oper
- *
- * NOTE: in the good old days 'opno' used to be both (or either, or
- * neither) the pg_operator oid, and/or the pg_proc oid depending
- * on the postgres module in question (parser->pg_operator,
- * executor->pg_proc, planner->both), the mood of the programmer,
- * and the phase of the moon (rumors that it was also depending on the day
- * of the week are probably false). To make things even more postgres-like
- * (i.e. a mess) some comments were referring to 'opno' using the name
- * 'opid'. Anyway, now we have two separate fields, and of course that
- * immediately removes all bugs from the code...		[ sp :-) ].
- *
- * Note also that opid is not necessarily filled in immediately on creation
- * of the node.  The planner makes sure it is valid before passing the node
- * tree to the executor, but during parsing/planning opid is typically 0.
- *--------------------
- */
-typedef struct Oper
-{
-	NodeTag		type;
-	Oid			opno;			/* PG_OPERATOR OID of the operator */
-	Oid			opid;			/* PG_PROC OID for the operator's
-								 * underlying function */
-	Oid			opresulttype;
-	/* PG_TYPE OID of the operator's return value */
-	FunctionCachePtr op_fcache;
-	/* runtime state while running the function */
-} Oper;
-
-
 /*
  * Const
  */
@@ -283,39 +291,6 @@ typedef struct Param
 	Oid			paramtype;		/* PG_TYPE OID of the parameter's value */
 } Param;
 
-
-/*
- * Func
- */
-typedef struct Func
-{
-	NodeTag		type;
-	Oid			funcid;			/* PG_PROC OID of the function */
-	Oid			functype;		/* PG_TYPE OID of the function's return
-								 * value */
-	FunctionCachePtr func_fcache;
-
-	/*
-	 * runtime state while running this function. Where we are in the
-	 * execution of the function if it returns more than one value, etc.
-	 * See utils/fcache.h
-	 */
-} Func;
-
-/* ----------------
- * Iter
- *		can anyone explain what this is for?  Seems to have something to do
- *		with evaluation of functions that return sets...
- * ----------------
- */
-typedef struct Iter
-{
-	NodeTag		type;
-	Node	   *iterexpr;
-	Oid			itertype;		/* type of the iter expr (use for type
-								 * checking) */
-} Iter;
-
 /*
  * Aggref
  */
diff --git a/src/include/optimizer/clauses.h b/src/include/optimizer/clauses.h
index 69596c1779a..376e8cc77aa 100644
--- a/src/include/optimizer/clauses.h
+++ b/src/include/optimizer/clauses.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: clauses.h,v 1.51 2002/04/05 00:31:35 tgl Exp $
+ * $Id: clauses.h,v 1.52 2002/05/12 23:43:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -42,7 +42,7 @@ extern List *make_ands_implicit(Expr *clause);
 extern bool contain_agg_clause(Node *clause);
 extern List *pull_agg_clause(Node *clause);
 
-extern bool contain_iter_clause(Node *clause);
+extern bool expression_returns_set(Node *clause);
 
 extern bool contain_subplans(Node *clause);
 extern List *pull_subplans(Node *clause);
diff --git a/src/include/parser/parse_coerce.h b/src/include/parser/parse_coerce.h
index 47ce9b61c16..a7eb56a5092 100644
--- a/src/include/parser/parse_coerce.h
+++ b/src/include/parser/parse_coerce.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parse_coerce.h,v 1.42 2002/04/11 20:00:15 tgl Exp $
+ * $Id: parse_coerce.h,v 1.43 2002/05/12 23:43:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,7 +45,7 @@ extern Node *coerce_type(ParseState *pstate, Node *node, Oid inputTypeId,
 extern Node *coerce_type_typmod(ParseState *pstate, Node *node,
 				   Oid targetTypeId, int32 atttypmod);
 
-extern bool coerce_to_boolean(ParseState *pstate, Node **pnode);
+extern Node *coerce_to_boolean(Node *node, const char *constructName);
 
 extern Oid	select_common_type(List *typeids, const char *context);
 extern Node *coerce_to_common_type(ParseState *pstate, Node *node,
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 9f812256737..eaff98448d3 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lsyscache.h,v 1.51 2002/04/30 01:26:26 tgl Exp $
+ * $Id: lsyscache.h,v 1.52 2002/05/12 23:43:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -39,6 +39,7 @@ extern RegProcedure get_oprrest(Oid opno);
 extern RegProcedure get_oprjoin(Oid opno);
 extern char *get_func_name(Oid funcid);
 extern Oid	get_func_rettype(Oid funcid);
+extern bool	get_func_retset(Oid funcid);
 extern char func_volatile(Oid funcid);
 extern Oid	get_relname_relid(const char *relname, Oid relnamespace);
 extern char *get_rel_name(Oid relid);