function
(length ds )
Returns the length or count of a data structure in constant time as
an integer. For structs and tables , returns the number of key-value
pairs in the data structure.
(map length [ 'a :a "a" [97 ] @[97 ] {0 97 } @{0 97 } ])
# => @[ 1 1 1 1 1 1 1 ]