github.com/hirochachacha/plua@v0.0.0-20170217012138-c82f520cc725/stdlib/debug/testdata/getupvalue.lua (about)

     1  local a,b,c = 1,2,3
     2  local function foo(a) b = a; return c end
     3  assert(debug.getupvalue(foo, 0) == nil)
     4  k, v = debug.getupvalue(foo, 1)
     5  assert(k == "b" and v == 2)
     6  k, v = debug.getupvalue(foo, 2)
     7  assert(k == "c" and v == 3)
     8  assert(debug.getupvalue(foo, 3) == nil)