argcheck (moonscript)

argcheck.moon

do
  checktypelist = (t,a1,...) ->
    t == a1 or checktypelist t,... if a1 ~= nil
  
  export argcheck = (val,argn,...) ->
    return if checktypelist type(val),...
    types = '/'\join tostringall ...
    fname = debug.getinfo(2,'n').name or 'unknown'
    error "bad argument ##{tonumber(argn) or '?'} to '#{fname}' (#{types} expected, got #{type val})",3