object.constraints.each do |c|
  p = object.particles[c.index]
  p.component_set(c.component,c.value) if p.component_value(c.component).send(c.dir, c.value)
...

class SomeObject
  def component_set(component,value)
    send("#{component}=", value)
...

object.constraints.each do |c|
  p = object.particles[c.index]
  if c.component == :x
...