[a] -> [a] -> (a -> a -> a) -> [a]
combine([1,2,3], [2,3,4], plus_func) => [3,5,7]
combine([1,2,3], [2,3,4], multiply_func) => [2,6,12]
def combine a, b
a.zip(b).map { |i| yield i[0], i[1] }
end
puts combine([1,2,3], [2,3,4]) { |i, j| i+j }
def combine(a, b, &block)
a.zip(b).map(&block)
end
def combine(a, b, *args, &block)
a.zip(b, *args).map(&block)
end
def combine(a1, a2)
i = 0
result = []
while a1[i] && a2[i]
result << yield(a1[i], a2[i])
i+=1
end
result
end
sum = combine([1,2,3], [2,3,4]) {|x,y| x+y}
prod = combine([1,2,3], [2,3,4]) {|x,y| x*y}
p sum, prod
=>
[3, 5, 7]
[2, 6, 12]
def combine(*args)
i = 0
result = []
while args.all?{|a| a[i]}
result << yield(*(args.map{|a| a[i]}))
i+=1
end
result
end
def combine(*args)
args.first.zip(*args[1..-1]).map {|a| yield a}
end
sum = combine([1,2,3], [2,3,4], [3,4,5]) {|ary| ary.inject{|t,v| t+=v}}
prod = combine([1,2,3], [2,3,4], [3,4,5]) {|ary| ary.inject(1){|t,v| t*=v}}
p sum, prod
class Symbol
# Turns the symbol into a simple proc, which is especially useful for enumerations.
def to_proc
Proc.new { |*args| args.shift.__send__(self, *args) }
end
end
(1..100).inject(&:+)