// Test demonstrating the difference between add (local scope) and add_global/set_global (global scope)
// See issue #554

// --- Local variables (var / add) are scoped ---
// A local variable defined in a block is not visible outside that block
var local_val = 10
assert_equal(local_val, 10)

// Local variables can be reassigned in scope
local_val = 20
assert_equal(local_val, 20)

// Local variables inside a function are not visible outside
def set_local() {
  var func_local = 99
  assert_equal(func_local, 99)
}
set_local()

// --- Globals (add_global) are visible everywhere, including inside functions ---
var g_val = 42
add_global(g_val, "my_global")

def check_global() {
  assert_equal(my_global, 42)
}
check_global()

// add_global throws if the global already exists
assert_throws("Name already exists in current context my_global", fun() { add_global(1, "my_global") })

// --- set_global overwrites an existing global ---
set_global(100, "my_global")
assert_equal(my_global, 100)

def check_global_updated() {
  assert_equal(my_global, 100)
}
check_global_updated()

// set_global can also create a new global if it doesn't exist
set_global(77, "new_global")
assert_equal(new_global, 77)