RosettaCodeData/Task/Playing-cards/Jq/playing-cards.jq
2023-07-01 13:44:08 -04:00

70 lines
1.9 KiB
Text

# Uncomment for gojq:
# def _nwise($n):
# def nw: if length <= $n then . else .[0:$n] , (.[$n:] | nw) end;
# nw;
# Output: a prn in range(0;$n) where $n is .
def prn:
if . == 1 then 0
else . as $n
| (($n-1)|tostring|length) as $w
| [limit($w; inputs)] | join("") | tonumber
| if . < $n then . else ($n | prn) end
end;
def knuthShuffle:
length as $n
| if $n <= 1 then .
else {i: $n, a: .}
| until(.i == 0;
.i += -1
| (.i + 1 | prn) as $j
| .a[.i] as $t
| .a[.i] = .a[$j]
| .a[$j] = $t)
| .a
end;
def Pip: ["A", "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K"];
def Suit: ["♦", "♣", "♥", "♠"];
def Card(pip; suit): pip + suit;
def Deck: Card(Pip[]; Suit[]);
# Deal one round of the cards in .deck to the players
# represented by .hands,
# but if there are not enough cards, do nothing except add .error to the input
# Input {deck, hands}
def deal:
(.hands | length) as $nplayers
| if $nplayers > (.deck|length) then .error = "not enough cards"
else reduce range(0;$nplayers) as $i (.; .hands[$i] += [.deck[$i]])
| .deck |= .[$nplayers:]
# Deal $n cards to $nplayers players if there are enough cards in the input deck
# Input: a deck
# Output: {deck, hands}
def deal($n; $nplayers):
if $n * $nplayers > length then "deal/2: not enough cards" | error
else {deck: ., hands: [range(0; $nplayers)|[]]}
| until( .hands[0]|length == $n; deal)
end ;
# display an entire deck or else just the cards
def display:
if length == 52 then _nwise(13) | join(" ")
else join(" ")
end;
def task:
Deck
| "After creation, the deck consists of:", display, "",
(knuthShuffle
| "After shuffling:", display, "",
( deal(5; 4)
| "After dealing 5 cards each to 4 players, the hands are:",
(.hands[] | display), "", "... leaving \(.deck|length) cards") ) ;
task