It appears the result of an assignment of the results of a call to Command#map, ends up with the variable pointing to the Command, rather than the result Array.
parkan@xldn3743vdap:~$ irb -rrubish
>> Rubish.repl
> ls
archived_ Documents logs Movies pkgs src
bin Downloads mmt Music public tmp
Desktop Library mob-dev Pictures Public vpworkspace
> files = ls.map
["archived_",
"bin",
"Desktop",
"Documents",
"Downloads",
"Library",
"logs",
"mmt",
"mob-dev",
"Movies",
"Music",
"Pictures",
"pkgs",
"public",
"Public",
"src",
"tmp",
"vpworkspace"]
> puts files
#<Rubish::Command:0x98e4c58 @args=[], @cmd="files", @quoted=false>
> files.class
Rubish::Command
> ls.map.class
Array
>
It appears the result of an assignment of the results of a call to Command#map, ends up with the variable pointing to the Command, rather than the result Array.