scala - Checking on a property of a collection of case-class instances -

consider simple case-class "card" 2 properties ("number" , "color") this:

case class card(number: int, color: string) 

consider sequence of cards one:

val cards = seq(   card(5, "red"),   card(7, "red"),   card(3, "black")) 

now suppose wanted solve these problems in scala-idiomatic way (functionally oriented?):

• find if cards have same color
• find if cards have same number
• find if cards in ascending order

concretely, have implement these functions:

// cards have same color? def havesamecolor(cards: seq[card], ifempty: boolean = true): boolean = {   ??? }  // cards have same number? def havesamenumber(cards: seq[card], ifempty: boolean = true): boolean = {   ??? }  // cards ordered ascendingly? def areascending(cards: seq[card], ifempty: boolean = true): boolean = {   ??? } 

what possible / best approaches? looping, recursing, folding, reducing?

forall short-quits met first false

def havesamecolor(cards: seq[card], ifempty: boolean = true) = {   if (cards.isempty)  ifempty    else cards.forall(x => x.color.equals(cards.head.color)) }  // not different approach def havesamenumber(cards: seq[card], ifempty: boolean = true): boolean = {   if (cards.isempty)  ifempty    else cards.forall(x => x.number == cards.head.number) }  def areascending(cards: seq[card], ifempty: boolean = true): boolean = {   if (cards.isempty)  ifempty   else cards.zip(cards.tail).forall{ case (prev, next) => prev.number <= next.number} } 

although, said

is clear default answer should in case of emptiness? not me.

as can see there lot of repetition in function -- clear sign there wrong -- go functions without ifempty parameter.