Pushing objects around in a dozen lines of code

I've been playing around with detecting and responding to collisions, just with simple rectangles. Here's today's example, with lots of help from the LÖVE Discord that pointed me to the batteries library in particular:

block1 = {pos={x=50,y=50}, hs={x=25,y=50}}
block2 = {pos={x=200,y=200}, hs={x=50,y=25}}
Move = nil
function car.draw()
  color(0.7, 0.5, 0.5)
  local r = block1
  rect('fill', r.pos.x-r.hs.x,r.pos.y-r.hs.y, r.hs.x*2,r.hs.y*2)
  color(0.5, 0.5, 0.5)
  r = block2
  rect('fill', r.pos.x-r.hs.x,r.pos.y-r.hs.y, r.hs.x*2,r.hs.y*2)
end
function car.mousepressed(x,y, button)
  if x < block1.pos.x - block1.hs.x then return end
  if x > block1.pos.x + block1.hs.x then return end
  if y < block1.pos.y - block1.hs.y then return end
  if y > block1.pos.y + block1.hs.y then return end
  Move = {target=block1, dx=x-block1.pos.x, dy=y-block1.pos.y}
end
function car.mousereleased(x,y, done)
  Move = nil
end
function car.update(dt)
  if Move == nil or Move.target ~= block1 then return end
  local x,y = love.mouse.getPosition()
  block1.pos.x = x-Move.dx
  block1.pos.y = y-Move.dy
  local msv = collide(block1.pos, block1.hs, block2.pos, block2.hs)
  if msv then
    block2.pos.x = block2.pos.x - msv.x
    block2.pos.y = block2.pos.y - msv.y
  end
end
-- returns the _minimum separation vector_ if there's a collision
function collide(apos, ahs, bpos, bhs)
  local delta = {x=apos.x-bpos.x, y=apos.y-bpos.y}
  local abs_delta = {x=abs(apos.x-bpos.x), y=abs(apos.y-bpos.y)}
  local size = {x=ahs.x+bhs.x, y=ahs.y+bhs.y}
  local abs_amount = {x=size.x-abs_delta.x, y=size.y-abs_delta.y}
  if abs_amount.x > 0 and abs_amount.y > 0 then
    if abs_amount.x <= abs_amount.y then
      return {x=abs_amount.x*sign(delta.x), y=0}
    else
      return {x=0, y=abs_amount.y*sign(delta.y)}
    end
  end
end
function sign(v)
  if v < 0 then return -1 end
  if v > 0 then return 1 end
  return 0
end

If you try pasting this program into Lua Carousel, remember to first run the abbreviations on one of the example screens. Or if you've deleted that screen, here are the abbreviations this program uses:

g = love.graphics
rect = g.rectangle
color = g.setColor
abs = math.abs