In many programs,
especially those involving widgets, large structures (e.g. the
‘state’
structure) are used to communicate among routines. It is very
convenient to be able to complete structure tags, in the same way
as for instance variables (tags) of the ‘self’ object (see
Object Method Completion and Class Ambiguity). Add-in code
for structure tag completion is available in the form of a
loadable completion module: idlw-complete-structtag.el. Tag completion
in structures is highly ambiguous (much more so than
‘self’
completion), so idlw-complete-structtag makes an
unusual and very specific assumption: the exact same variable
name is used to refer to the structure in all parts of the
program. This is entirely unenforced by the IDL language, but is
a typical convention. If you consistently refer to the same
structure with the same variable name (e.g.
‘state’),
structure tags which are read from its definition in the same
file can be used for completion.
Structure tag completion is not enabled by default. To enable it, simply add the following to your .emacs:
(add-hook 'idlwave-load-hook
(lambda () (require 'idlw-complete-structtag)))
Once enabled, you'll also be able to access online help on the structure tags, using the usual methods (see Online Help). In addition, structure variables in the shell will be queried for tag names, similar to the way object variables in the shell are queried for method names. So, e.g.:
IDL> st.[Tab]
will complete with all structure fields of
the structure st.