library vectors
    
    struct vector
        real x
        real y
        real z
        static method create takes real x, real y, real z returns vector
            local vector v = vector.allocate()
            set v.x=x
            set v.y=y
            set v.z=z
            return v
        endmethod

        method realmul takes real r returns nothing
            set .x=.x*r
            set .y=.y*r
            set .z=.z*r
        endmethod
        
        method getlength takes nothing returns real
            return SquareRoot(.x*.x+.y*.y+.z*.z)
        endmethod
        
        method normalize takes nothing returns nothing
            local real l = .getlength()
            if l>0 then
                call .realmul(1/l)
            endif
        endmethod   
        
        method setlength takes real r returns nothing
            local real l = .getlength()
            if l>0 then
                call .realmul(r/l)
            endif
        endmethod
        
        method scalarmul takes vector v returns real
            return .x*v.x+.y*v.y+.z*v.z
        endmethod
        
        method vectorsum takes vector v returns nothing
            set .x=.x+v.x
            set .y=.y+v.y
            set .z=.z+v.z
        endmethod    
        
        method vectormul takes vector v returns nothing
            local real x = .y*v.z-v.y*.z
            local real y = .z*v.x-v.z*.x
            local real z = .x*v.y-v.x*.y
            set .x = x
            set .y = y
            set .z = z
        endmethod
        
        method clone takes nothing returns vector
            local vector v=vector.allocate()
            set v.x=.x
            set v.y=.y
            set v.z=.z
            return v
        endmethod      
        
        method copy takes vector p returns nothing
            set .x=p.x
            set .y=p.y
            set .z=p.z            
        endmethod
        
        method change takes real x, real y, real z returns nothing
            set .x=x
            set .y=y
            set .z=z
        endmethod
    endstruct    
    
endlibrary

local vector v = vector.create(0,0,0)

local vector v = vector.create(1,1,1)
call v.realmul(2)
//результат вектор с координатами 2 2 2

local vector v = vector.create(0,0,1)
local real r = v.getlength()
//результат равен 1

local vector v = vector.create(54,0,0)
call v.normalize()
//результат: вектор а равен 1 0 0

local vector v = vector.create(54,0,0)
call v.setlength(30)
//результат: вектор а равен 30 0 0

local vector v = vector.create(1,2,3)
local vector w = vector.create(1,0,3)
local real r = v.scalarmul(w)
//результат равен 10

local vector v = vector.create(1,2,3)
local vector w = vector.create(1,0,3)
local real r = v.vectorsum(w)
//результат: вектор v равен 2 2 6, вектор w не изменился

local vector v = vector.create(1,0,0)
local vector w = vector.create(0,1,0)
local real r = v.vectormul(w)
//результат: вектор v равен 0 0 1, вектор w не изменился

local vector v = vector.create(1,0,0)
local vector w = vector.clone()
//результат: вектор v равен 1 0 0, вектор w равен 1 0 0

local vector v = vector.create(1,0,0)
local vector w = vector.create(0,1,0)
call v.copy(w)
//результат: вектор v равен 0 1 0, вектор w равен 0 1 0

local vector v = vector.create(1,0,0)
call v.change(1,1,1)
//результат: вектор v равен 1 1 1