and hopefully improve code clarity while at it.  One intentional
semantics change: a backslashed space will not be treated as removable
trailing whitespace, as the prior coding would do.  ISTM that if it
wouldn't be considered removable leading whitespace, it shouldn't be
stripped at the end either.

cosmetic code cleanup at the same time.

of <ctype.h> macros.

from being accepted after the outer right brace. Per report from
Markus Bertheau.

Also add regression test cases for this change, and for previous
recent array literal parser changes.

was previously allowed in odd places with odd results now causes an ERROR.
Also changed behavior with respect to whitespace -- trailing whitespace is
now ignored as well as leading whitespace (which has always been ignored).

Documentation updated to reflect change in whitespace handling. Also some
refactoring to what I believe is a more sensible order of several paragraphs.

subarrays of a given dimension have the same number of elements/subarrays.

Also repair a longstanding undocumented (as far as I can see) ability to
explicitly set array bounds in the array literal syntax. It now can
deal properly with negative array indicies. Modify array_out so that
arrays with non-standard lower bounds (i.e. not 1) are output with
the expicit dimension syntax. This fixes a longstanding issue whereby
arrays with non-default lower bounds had them changed to default
after a dump/reload cycle.

Modify regression tests and docs to suit, and add some minimal
documentation regarding the explicit dimension syntax.

eliminating the former hard-wired convention about their names.  Allow
pg_cast entries to represent both type coercion and length coercion in
a single step --- this is represented by a function that takes an
extra typmod argument, just like a length coercion function.  This
nicely merges the type and length coercion mechanisms into something
at least a little cleaner than we had before.  Make use of the single-
coercion-step behavior to fix integer-to-bit coercion so that coercing
to bit(n) yields the rightmost n bits of the integer instead of the
leftmost n bits.  This should fix recurrent complaints about the odd
behavior of this coercion.  Clean up the documentation of the bit string
functions, and try to put it where people might actually find it.
Also, get rid of the unreliable heuristics in ruleutils.c about whether
to display nested coercion steps; instead require parse_coerce.c to
label them properly in the first place.

array.

of a composite type to get that type's OID as their second parameter,
in place of typelem which is useless.  The actual changes are mostly
centralized in getTypeInputInfo and siblings, but I had to fix a few
places that were fetching pg_type.typelem for themselves instead of
using the lsyscache.c routines.  Also, I renamed all the related variables
from 'typelem' to 'typioparam' to discourage people from assuming that
they necessarily contain array element types.

pointer type when it is not necessary to do so.

For future reference, casting NULL to a pointer type is only necessary
when (a) invoking a function AND either (b) the function has no prototype
OR (c) the function is a varargs function.

$Header: -> $PostgreSQL Changes ...

terms, add some clarifications, fix some untranslatable attempts at dynamic
message building.

datatype by array_eq and array_cmp; use this to solve problems with memory
leaks in array indexing support.  The parser's equality_oper and ordering_oper
routines also use the cache.  Change the operator search algorithms to look
for appropriate btree or hash index opclasses, instead of assuming operators
named '<' or '=' have the right semantics.  (ORDER BY ASC/DESC now also look
at opclasses, instead of assuming '<' and '>' are the right things.)  Add
several more index opclasses so that there is no regression in functionality
for base datatypes.  initdb forced due to catalog additions.

faster, but more importantly does not leak memory.  Still needs more work
though, per my recent note to pgsql-hackers.

the bulk of the heavy lifting ...

ANYELEMENT.  The effect is to postpone typechecking of the function
body until runtime.  Documentation is still lacking.

Original patch by Joe Conway, modified to postpone type checking
by Tom Lane.

comparison functions), replacing the highly bogus bitwise array_eq.  Create
a btree index opclass for ANYARRAY --- it is now possible to create indexes
on array columns.
Arrange to cache the results of catalog lookups across multiple array
operations, instead of repeating the lookups on every call.
Add string_to_array and array_to_string functions.
Remove singleton_array, array_accum, array_assign, and array_subscript
functions, since these were for proof-of-concept and not intended to become
supported functions.
Minor adjustments to behavior in some corner cases with empty or
zero-dimensional arrays.

Joe Conway (with some editorializing by Tom Lane).

Joe Conway

Joe Conway

the folly of not passing element type to typsend/typreceive, so fix that.

yet, but they're there.  Also some editorial work on CREATE TYPE reference
page.

expressions, ARRAY(sub-SELECT) expressions, some array functions.
Polymorphic functions using ANYARRAY/ANYELEMENT argument and return
types.  Some regression tests in place, documentation is lacking.
Joe Conway, with some kibitzing from Tom Lane.

cannot actually happen at present because ArrayCount() is only called
on strings beginning with '{', but seems best to prevent it going forward.
Per report from Yichen Xie.

to MemSet is a performance boost.

now)" item on the open items, and subsequent plpgsql function I sent in,
made me realize it was too hard to get the upper and lower bound of an
array. The attached creates two functions that I think will be very
useful when combined with the ability of plpgsql to return sets.

array_lower(array, dim_num)
- and -
array_upper(array, dim_num)

They return the value (as an int) of the upper and lower bound of the
requested dim in the provided array.

Joe Conway

to be flexible about assignment casts without introducing ambiguity in
operator/function resolution.  Introduce a well-defined promotion hierarchy
for numeric datatypes (int2->int4->int8->numeric->float4->float8).
Change make_const to initially label numeric literals as int4, int8, or
numeric (never float8 anymore).
Explicitly mark Func and RelabelType nodes to indicate whether they came
from a function call, explicit cast, or implicit cast; use this to do
reverse-listing more accurately and without so many heuristics.
Explicit casts to char, varchar, bit, varbit will truncate or pad without
raising an error (the pre-7.2 behavior), while assigning to a column without
any explicit cast will still raise an error for wrong-length data like 7.3.
This more nearly follows the SQL spec than 7.2 behavior (we should be
reporting a 'completion condition' in the explicit-cast cases, but we have
no mechanism for that, so just do silent truncation).
Fix some problems with enforcement of typmod for array elements;
it didn't work at all in 'UPDATE ... SET array[n] = foo', for example.
Provide a generalized array_length_coerce() function to replace the
specialized per-array-type functions that used to be needed (and were
missing for NUMERIC as well as all the datetime types).
Add missing conversions int8<->float4, text<->numeric, oid<->int8.
initdb forced.

array header, and to compute sizing and alignment of array elements
the same way normal tuple access operations do --- viz, using the
tupmacs.h macros att_addlength and att_align.  This makes the world
safe for arrays of cstrings or intervals, and should make it much
easier to write array-type-polymorphic functions; as examples see
the cleanups of array_out and contrib/array_iterator.  By Joe Conway
and Tom Lane.

okay to omit low-order dimensions when accessing an array slice.

before a data item is now always skipped, rather than only sometimes.
Backslashes not within double-quoted text are treated reasonably, as
are multiple sequences of quoted text in a single data item.  But it
still seems rather prone to misbehavior if the input is not completely
syntactically correct --- in particular, garbage following a right brace
will be ignored.

bounds of 1, not the lower bound subscripts of the original slice.
Per bug report from Andre Holzner, 1-Feb-02.

return NULL.