Re: try... query

Am 06.12.24 um 14:11 schrieb Alan Grunwald:

I'm attempting to get my head around preventing resource leaks, using try and return.

I haven't worked through your code, but in C++, there is a great idiom called RAII - things get destroyed when the variable goes out of scope. This can be simulated for Tcl using a delete trace on the variable.
Using the little utils package from here: https://github.com/BessyHDFViewer/BessyHDFViewer/tree/main/bessyhdfviewer.vfs/lib/SmallUtils
You can do this for files:
proc something {} {
SmallUtils::autofd fd somewfile w
puts $fd "Text comes here"
}
# fd goes out of scope, file is closed
and for any objects that work Tk-like, giving a command back:
SmallUtils::autovar btn button .b -text "Hi"
# will destroy if btn goes out of scope
# by "rename .b {}"
Of course, this is not perfect, it will fail if you copy the variable somewhere else, but often times it is good enough.
                Christian