You are not putting parens around the map arguments, saving one character. You have block delimiters around the first map argument instead of parens around both arguments, so you don't need the comma to separate the two arguments. Congratulations :)

Update: Though it seems the parens were completely unnecessary (though a space between map and the first arg is necessary in japhy's answer, so now your answer's are tied, i.e. length('map func,@arr')==length('map{func}@array')).