Righto, this is going to be hideous (Please bear in mind i am writing
this from experience of mappings, not from knowledge of how they *work*
-- bil).
Mappings are a wonder new data structure, which i think it a friendly
version of alists in the basic 3.0 code (you don't need to know this).
They are wonderful because they allow you to index values from
anything, not just an integer (as in a normal array/list).
They can be created like this:-
mapping fish;
fish = ([
"womble": 12,
"bing" : 6,
"spam" : 42
]);
What you have done there is set the index "womble" to the value 12,
"bing" to 6 and "spam" to 42. To retrieve values you index in the same
way as with arrays ie mapping[index]. In this example
fish["womble"] == 12 and fish["bing"] == 6. If an index does not exist,
then a 0 is returned. eg fish["spoon"] == 0.
If you wish to set a value later, you can use mapping[index] = value
and it will be set, whether index existed before or not (but mapping
must already have been initialised - as above, with fish = ([ ]); or
by using mkmapping (see mkmapping help) eg.
fish["boom"] = 666;
fish["bing"] = 2;
Note that the type of both the indexes and values have type mixed
so can be of any sort. And can be freely mixed within a single mapping eg.
fish["example mixed array"] = ({ "what fun!", ({ 1, 1, 4 }) });
See also:
mappingp, mkmapping, m_sizeof, m_indices, m_values, m_delete
