Lua 5.2+ uses loadfile(filename, mode, env), not loadfile(filename,
env). While this is a minor incompatibility, it'd be nice to be
consistent as much as possible.
We try to handle the incorrect case too, as obviously we don't want to
break existing programs.
This moves expect from the bios into a new craftos.expect module,
removing the internal _G["~expect"] definition. Apparently people were
using this irrespective of the "don't use this" comment, so we need to
find another solution.
While this does introduce some ugliness (having to load the module in
weird ways for programs, duplicating the expect function in memory), it
does allow people to use the function in a supported way, and removes
the global ugliness.
- Define an expect(index, actual_value, types...) helper function which
takes an argument index, value and list of permissable types and
ensures the value is of one of those types.
If not, it will produce an error message with the expected and actual
type, as well as the argument number and (if available) the function
name.
- Expose expect in the global scope as _G["~expect"], hopefully making
it clear it is internal.
- Replace most manual type checks with this helper method.
- Write tests to ensure this argument validation works as expected
Also fix a couple of bugs exposed by this refactor and the subsequent
tests:
- Make rednet checks a little more strict - rednet.close(false) is no
longer valid.
- Error when attempting to redirect the terminal to itself
(term.redirect(term)).
- Share the ILuaContext across all method calls, as well as shifting it
into an anonymous class.
- Move the load/loadstring prefixing into bios.lua
- Be less militant in prefixing chunk names:
- load will no longer do any auto-prefixing.
- loadstring will not prefix when there no chunk name is supplied.
Before we would do `"=" .. supplied_program`, which made no sense.
