Improve contrib/cube's handling of zero-D cubes, infinities, and NaNs.

It's always been possible to create a zero-dimensional cube by converting
from a zero-length float8 array, but cube_in failed to accept the '()'
representation that cube_out produced for that case, resulting in a
dump/reload hazard.  Make it accept the case.  Also fix a couple of
other places that didn't behave sanely for zero-dimensional cubes:
cube_size would produce 1.0 when surely the answer should be 0.0,
and g_cube_distance risked a divide-by-zero failure.

Likewise, it's always been possible to create cubes containing float8
infinity or NaN coordinate values, but cube_in couldn't parse such input,
and cube_out produced platform-dependent spellings of the values.  Convert
them to use float8in_internal and float8out_internal so that the behavior
will be the same as for float8, as we recently did for the core geometric
types (cf commit 50861cd68).  As in that commit, I don't pretend that this
patch fixes all insane corner-case behaviors that may exist for NaNs, but
it's a step forward.

(This change allows removal of the separate cube_1.out and cube_3.out
expected-files, as the platform dependency that previously required them
is now gone: an underflowing coordinate value will now produce an error
not plus or minus zero.)

Make errors from cube_in follow project conventions as to spelling
("invalid input syntax for cube" not "bad cube representation")
and errcode (INVALID_TEXT_REPRESENTATION not SYNTAX_ERROR).

Also a few marginal code cleanups and comment improvements.

Tom Lane, reviewed by Amul Sul

Discussion: <[email protected]>

1 files changed, 8 insertions, 3 deletions

diff --git a/contrib/cube/sql/cube.sql b/contrib/cube/sql/cube.sql
index e225fb7da18..cc5a1ce4588 100644
--- a/contrib/cube/sql/cube.sql
+++ b/contrib/cube/sql/cube.sql
@@ -29,8 +29,11 @@ SELECT '1e-7'::cube AS cube;
 SELECT '-1e-7'::cube AS cube;
 SELECT '1.0e-7'::cube AS cube;
 SELECT '-1.0e-7'::cube AS cube;
-SELECT '1e-700'::cube AS cube;
-SELECT '-1e-700'::cube AS cube;
+SELECT '1e-300'::cube AS cube;
+SELECT '-1e-300'::cube AS cube;
+SELECT 'infinity'::cube AS cube;
+SELECT '-infinity'::cube AS cube;
+SELECT 'NaN'::cube AS cube;
 SELECT '1234567890123456'::cube AS cube;
 SELECT '+1234567890123456'::cube AS cube;
 SELECT '-1234567890123456'::cube AS cube;
@@ -39,12 +42,14 @@ SELECT '+.1234567890123456'::cube AS cube;
 SELECT '-.1234567890123456'::cube AS cube;
 
 -- simple lists (points)
+SELECT '()'::cube AS cube;
 SELECT '1,2'::cube AS cube;
 SELECT '(1,2)'::cube AS cube;
 SELECT '1,2,3,4,5'::cube AS cube;
 SELECT '(1,2,3,4,5)'::cube AS cube;
 
 -- double lists (cubes)
+SELECT '(),()'::cube AS cube;
 SELECT '(0),(0)'::cube AS cube;
 SELECT '(0),(1)'::cube AS cube;
 SELECT '[(0),(0)]'::cube AS cube;
@@ -57,7 +62,6 @@ SELECT '[(0,0,0,0),(1,0,0,0)]'::cube AS cube;
 -- invalid input: parse errors
 SELECT ''::cube AS cube;
 SELECT 'ABC'::cube AS cube;
-SELECT '()'::cube AS cube;
 SELECT '[]'::cube AS cube;
 SELECT '[()]'::cube AS cube;
 SELECT '[(1)]'::cube AS cube;
@@ -85,6 +89,7 @@ SELECT '1,2ab'::cube AS cube; -- 6
 SELECT '1 e7'::cube AS cube; -- 6
 SELECT '1,2a'::cube AS cube; -- 7
 SELECT '1..2'::cube AS cube; -- 7
+SELECT '-1e-700'::cube AS cube; -- out of range
 
 --
 -- Testing building cubes from float8 values