1.1 --- a/docs/syspython.txt Fri Jul 05 23:13:22 2013 +0200
1.2 +++ b/docs/syspython.txt Sun Jul 07 21:06:01 2013 +0200
1.3 @@ -23,6 +23,27 @@
1.4 or method. Note that the apply function resembles the Python function of the
1.5 same name but is not actually that particular function.
1.6
1.7 +Low-Level Code
1.8 +--------------
1.9 +
1.10 +Most Python-level program code should be wrapped in special function
1.11 +invocations, and as a result other syntax features might be used to express
1.12 +low-level concepts. Low-level operations may also be expressed using other
1.13 +special functions. For example:
1.14 +
1.15 + storelocal(element, loadobjtable(loadattr(obj, classcode), attrcode))
1.16 +
1.17 +Here, element holds the raw data provided by the table access involving a base
1.18 +defined by the classcode of an object and an offset defined by the supplied
1.19 +attrcode.
1.20 +
1.21 +Note that all low-level functions deal only with addresses and offsets, not
1.22 +symbols. In the above example, loadattr combines the address of obj with the
1.23 +symbol classcode whose actual value must be substituted by the compiler.
1.24 +However, the loadobjtable function requires a genuine offset value for the
1.25 +classcode (which is why loadattr is being used to obtain it), and a genuine
1.26 +offset for the attrcode (which is provided directly).
1.27 +
1.28 Program Data and Data Structure Definition
1.29 ------------------------------------------
1.30