Support to rewrite vector in component-wise for statement

[ghost]

#I'm sorry for my bad English.

I want to rewrite vector or matrix in component-wise for statement, but now neo doesn't support that.

When we rewrite some component of a vector, now we can do that with the following code .

import neo
var
    vec = vector([1, 2, 3])


for i in 0..<vec.len:
    vec[i] = 0

echo vec #result in [0, 0, 0]

Of corse, this code is enough work.

However, the following code is more useful for our neo life.

import neo

iterator mitems[T](a: var Vector[T]): var T = 
    var 
        cnt = 0

    while cnt < a.len:
        yield a[cnt]
        cnt.inc

var
    vec = vector([1, 2, 3])


for elem in vec.mitems:
    elem = 0

echo vec #result in [0, 0, 0]

'mitems' is an iterator which is implemented for seq, array and etc..., but now it is not implemented for either vector or matrix.

I wish 'mitems' is implemented for vector and matrix.