Scala Functional programming

Learned some of Scala's basic grammar http://twitter.github.io/scala_school/zh_cn/index.html,

Try Scala's functional programming.

How to implement with functional programming: SUM (f, a, b) =

s = 0

For i in [A, b]

S+=f (i)

return s

This is the pseudo-code for imperative programming, C/s + +.

1. Implementation 1.

1 def sum (f:int=>int, A:int, b:int): Int = {2     if(a > B) 0 else F (a) + SUM (a+1 , B) 3 }

SUM (x=>x, 1, 5)

SUM (x=>x*x*x, 1, 5)

2. Implementation 2

Here are three parameters, F, a, B. Is it possible to abstract sum into an input of f, and the output is a function of G: (int, int) =>int? And then use the generated G effect to a, B?

1 def sum (f:int=>int):(int, int) =>int = {2   def func (A:int, b:int): int = { 3       if (A > B) 0 else F (a) +func (a+1, b)          4  }    5 }

SUM (x=>x) (1,5)

SUM (x=>x*x*x) (1,5)

The f is abstracted out.

Scala Functional programming