[Ifeffit] formula checking
newville at cars.uchicago.edu
Mon Nov 22 12:31:10 CST 2004
Here's a proposed change for checking for syntax and other errors. (This
would make v. 1.2.7. I might be willing to toss in a few more things too).
First, and mostly, add '&status' variable to hold status flags from
commands. The values of &status could be (open for suggestion):
0.0 no error (see below)
1.0 benign warnings (eg, 'unknown keyword' for commands)
2.0 more serious warnings: syntax errors, evaluation errors
(divide-by-zero), or a command stopped prematurely for
some other reason (eg, "can't find an array for energy").
3.0 severe warnings: hitting an internal program limit,
'file not found', and so on.
Those could be changed or expanded, to say, be along the lines of:
1.1 'unknown keyword'
1.2 'data out of order for spline/pre_edge....'
1.3 fit couldn't determine error bars....
2.0 syntax error during parsing
2.1 evaluation error (eg, divide-by-zero)
2.2 can't find enough arrays to process command
and so on. That's mostly a matter of how detailed of the value
should be as opposed to parsing the strings that would be in the
echo buffer. I'd imagine that more &status values would be better
than parsing the messages.
I would also propose that &status is _not_ automatically set to 0
prior to each command. This would mean that the user / script
writer would have to explicilty set &status = 0 as a way to 'clear
warning messages'. That would lead to a wrapper around ifeffit
that does this (ignoring the saving,logging of the command):
set &status to 0
react to &status (maybe look at echo buffer at this point)
on the whole, that first 'set &status to 0' doesn't seem so bad. The
important reason to _not_ automatically reset &status is so that
warnings stick even when multiple commands and macros are run.
So, the main questions to you, Sam, and anyone else who's
interested in writing extended scripts / programs are:
Is this an OK approah?
How fine-grained should the values of &status be?
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