diff options
Diffstat (limited to 'src/include/nodes/primnodes.h')
| -rw-r--r-- | src/include/nodes/primnodes.h | 54 |
1 files changed, 29 insertions, 25 deletions
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h index 78fb0e414e3..a7efae70381 100644 --- a/src/include/nodes/primnodes.h +++ b/src/include/nodes/primnodes.h @@ -368,18 +368,19 @@ typedef struct WindowFunc } WindowFunc; /* ---------------- - * ArrayRef: describes an array subscripting operation - * - * An ArrayRef can describe fetching a single element from an array, - * fetching a subarray (array slice), storing a single element into - * an array, or storing a slice. The "store" cases work with an - * initial array value and a source value that is inserted into the - * appropriate part of the array; the result of the operation is an - * entire new modified array value. - * - * If reflowerindexpr = NIL, then we are fetching or storing a single array - * element at the subscripts given by refupperindexpr. Otherwise we are - * fetching or storing an array slice, that is a rectangular subarray + * SubscriptingRef: describes a subscripting operation over a container + * (array, etc). + * + * A SubscriptingRef can describe fetching a single element from a container, + * fetching a part of container (e.g. array slice), storing a single element into + * a container, or storing a slice. The "store" cases work with an + * initial container value and a source value that is inserted into the + * appropriate part of the container; the result of the operation is an + * entire new modified container value. + * + * If reflowerindexpr = NIL, then we are fetching or storing a single container + * element at the subscripts given by refupperindexpr. Otherwise we are + * fetching or storing a container slice, that is a rectangular subcontainer * with lower and upper bounds given by the index expressions. * reflowerindexpr must be the same length as refupperindexpr when it * is not NIL. @@ -391,28 +392,31 @@ typedef struct WindowFunc * element; but it is the array type when doing subarray fetch or either * type of store. * - * Note: for the cases where an array is returned, if refexpr yields a R/W - * expanded array, then the implementation is allowed to modify that object + * Note: for the cases where a container is returned, if refexpr yields a R/W + * expanded container, then the implementation is allowed to modify that object * in-place and return the same object.) * ---------------- */ -typedef struct ArrayRef +typedef struct SubscriptingRef { Expr xpr; - Oid refarraytype; /* type of the array proper */ - Oid refelemtype; /* type of the array elements */ - int32 reftypmod; /* typmod of the array (and elements too) */ + Oid refcontainertype; /* type of the container proper */ + Oid refelemtype; /* type of the container elements */ + int32 reftypmod; /* typmod of the container (and elements too) */ Oid refcollid; /* OID of collation, or InvalidOid if none */ List *refupperindexpr; /* expressions that evaluate to upper - * array indexes */ + * container indexes */ List *reflowerindexpr; /* expressions that evaluate to lower - * array indexes, or NIL for single array - * element */ - Expr *refexpr; /* the expression that evaluates to an array - * value */ + * container indexes, or NIL for single + * container element */ + List *refindexprslice; /* whether or not related indexpr from + * reflowerindexpr is a slice */ + Expr *refexpr; /* the expression that evaluates to a + * container value */ + Expr *refassgnexpr; /* expression for the source value, or NULL if * fetch */ -} ArrayRef; +} SubscriptingRef; /* * CoercionContext - distinguishes the allowed set of type casts @@ -755,7 +759,7 @@ typedef struct FieldSelect * * FieldStore represents the operation of modifying one field in a tuple * value, yielding a new tuple value (the input is not touched!). Like - * the assign case of ArrayRef, this is used to implement UPDATE of a + * the assign case of SubscriptingRef, this is used to implement UPDATE of a * portion of a column. * * resulttype is always a named composite type (not a domain). To update |