Are we having a code example party? I like Clojure:
(map :total orders) (map :total orders)Too often, differences between programming languages are treated as strictly philosophical arguments. Comparing and contrasting actual code is far more interesting, in my opinion.
select total from orders
(defmacro select [total _ coll]
(let [total (keyword total)]
`(map ~total ~coll)))
(select total from orders)
Here are some interesting non-macro variants, first in Rebol:
select: func [block] [
totals: []
parse block [
set this word!
'from
set coll word!
(totals: map-each n (get coll) [get in n this])
]
totals
]
; then later...
select [total from orders]
;; nb. `select` is a core function provided by Rebol
;; so remember this example overwrites that
;; (in this scope/context) :)
;;
;; Alternative `dialect` to strive for would be..
;;
;; doMap [select total from orders]
select := method(
msg := call argAt(0)
this := msg name
coll := msg next next name
newMsg := message(COLL map) // COLL just a placeholder message
newMsg setName(coll) // Now been changed to correct var provided
newMsg next appendArg(this asMessage)
call sender doMessage(newMsg)
)
# then later...
select(total from orders)
orders.map(&:total)
More detail: http://stackoverflow.com/a/1217114/3528
map *.total, @orders; # perl6
@orders.map: *.total; # perl6 OO
map {$_->total} @orders; # perl5
orders map(total) # Io
map-each n orders [n/total] ; Rebol