SELECT '{1:1.5,3:3.5}/5'::sparsevec;
    sparsevec    
-----------------
 {1:1.5,3:3.5}/5
(1 row)

SELECT '{1:1.5,3:3.5}/5'::sparsevec::vector;
     vector      
-----------------
 [1.5,0,3.5,0,0]
(1 row)

SELECT ''::sparsevec;
ERROR:  malformed sparsevec literal: ""
LINE 1: SELECT ''::sparsevec;
               ^
DETAIL:  Vector contents must start with "{".
SELECT '{'::sparsevec;
ERROR:  malformed sparsevec literal: "{"
LINE 1: SELECT '{'::sparsevec;
               ^
DETAIL:  Unexpected end of input.
SELECT '{}'::sparsevec;
ERROR:  malformed sparsevec literal: "{}"
LINE 1: SELECT '{}'::sparsevec;
               ^
DETAIL:  Unexpected end of input.
SELECT '{}/'::sparsevec;
ERROR:  invalid input syntax for type sparsevec: "{}/"
LINE 1: SELECT '{}/'::sparsevec;
               ^
SELECT '{}/1a'::sparsevec;
ERROR:  malformed sparsevec literal: "{}/1a"
LINE 1: SELECT '{}/1a'::sparsevec;
               ^
DETAIL:  Junk after closing.
SELECT '{:1}/1'::sparsevec;
ERROR:  invalid input syntax for type sparsevec: "{:1}/1"
LINE 1: SELECT '{:1}/1'::sparsevec;
               ^
SELECT '{1:}/1'::sparsevec;
ERROR:  invalid input syntax for type sparsevec: "{1:}/1"
LINE 1: SELECT '{1:}/1'::sparsevec;
               ^
SELECT '{1a:1}/1'::sparsevec;
ERROR:  invalid input syntax for type sparsevec: "{1a:1}/1"
LINE 1: SELECT '{1a:1}/1'::sparsevec;
               ^
SELECT '{1:1a}/1'::sparsevec;
ERROR:  invalid input syntax for type sparsevec: "{1:1a}/1"
LINE 1: SELECT '{1:1a}/1'::sparsevec;
               ^
SELECT '{1:1,}/1'::sparsevec;
ERROR:  invalid input syntax for type sparsevec: "{1:1,}/1"
LINE 1: SELECT '{1:1,}/1'::sparsevec;
               ^
SELECT '{1:0,2:1,3:0}/3'::sparsevec;
 sparsevec 
-----------
 {2:1}/3
(1 row)

SELECT '{2:1,1:1}/2'::sparsevec;
ERROR:  indexes must be in ascending order
LINE 1: SELECT '{2:1,1:1}/2'::sparsevec;
               ^
SELECT '{}/5'::sparsevec;
 sparsevec 
-----------
 {}/5
(1 row)

SELECT '{}/-1'::sparsevec;
ERROR:  sparsevec must have at least 1 dimension
LINE 1: SELECT '{}/-1'::sparsevec;
               ^
SELECT '{}/100001'::sparsevec;
ERROR:  sparsevec cannot have more than 100000 dimensions
LINE 1: SELECT '{}/100001'::sparsevec;
               ^
SELECT '{}/16001'::sparsevec::vector;
ERROR:  vector cannot have more than 16000 dimensions
SELECT '{0:1}/1'::sparsevec;
ERROR:  index "0" is out of range for type sparsevec
LINE 1: SELECT '{0:1}/1'::sparsevec;
               ^
SELECT '{2:1}/1'::sparsevec;
ERROR:  index must be less than or equal to dimensions
LINE 1: SELECT '{2:1}/1'::sparsevec;
               ^
SELECT '{}/1'::sparsevec(2);
ERROR:  expected 2 dimensions, not 1
SELECT '{1:1.5,3:3.5}/5'::sparsevec::vector(5);
     vector      
-----------------
 [1.5,0,3.5,0,0]
(1 row)

SELECT '{1:1.5,3:3.5}/5'::sparsevec::vector(4);
ERROR:  expected 4 dimensions, not 5