foo.x.y.z = 20
^
|
field_of 'z' (field_of 'y' (field_of 'x' (func_param "foo")))
does
	1 <- gep foo, (offset of 'x')
	2 <- gep 2, (offset of 'y')
	3 <- gep 3, (offset of 'z')
	store 3, "20"

foo().x = 20
^
|
field_of 'x' (temporary @1)"
does
	1 <- gep @1, (offset of 'x')
	store 1, "20"

my_dict["x"] = 20
^
|
subscript_operator (func_param "my_dict") (literal @2)
does
	call "Dictionary::operator[]=" (my_dict, @2)