[Tutor] using exceptions to implement case/switch?

[Bill Campbell]

I'm looking for feedback on the pros and cons of using exceptions to
implement constructions similar to the C switch or other language's case
statements.

I'm in the process of converting bunch of C code that makes extensive use
of switch() statements.  In particular I'm doing a python curses
implementation where it's parsing keys as they are pressed with different
case parts when special keys are hit.  Rather than doing this with a set of
``if'' statements, this could be done using exceptions, perhaps as in the
code below.

# start
import curses
import curses.ascii as ascii

keyf1 = 'key F1 pressed'
keyf2 = 'key F2 pressed'
keyf3 = 'key F3 pressed'
keyf4 = 'key F4 pressed'
# ...

def getchar(win):
	'''Get printable character from curses window'''
	while True:
		c = win.getch()
		if ascii.isprint(c) : return c
		if c == curses.KEY_F1 : raise keyf1
		if c == curses.KEY_F2 : raise keyf2
		if c == curses.KEY_F3 : raise keyf3
		if c == curses.KEY_F4 : raise keyf4
		curses.beep()

win = something_to_initialize_curses_window()

while True:
	try:
		c = getchar(win)
	except keyf1:
		process_keyF1()
	except (keyf2, keyf3):
		process_keyf2andf3()
	except keyf4:
		process keyf4()
	# ...
#end...

Bill
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