Re: Lightweight Lua Enumerations
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- Subject: Re: Lightweight Lua Enumerations
- From: Roberto Waltman <rwaltman@...>
- Date: 2007年6月28日 11:14:15 -0400
Gavin Kistner wrote:
What do _you_ do when you need a simple, lightweight way to create some
unique values? Do you worry about cross-enumeration comparisons? Do you
use strings?
I begun using strings, then switched to tables to save typing the
quotes. The following example is not really for enumerations, but the
same idea applies. I have many similar functions. The
victims^H^H^H^H^H^H^H users of my code can then type bias(reset),
bias(max), bias(10), etc.
In the future I may use the same but capitalize the table names, to
avoid conflicts with Lua keywords.
-- ---------------------------------------------------------------------
-- Objects to be used as dummy function parameters
-- ---------------------------------------------------------------------
again = {}
all = {}
back = {}
clear = {}
continue = {}
default = {}
first = {}
get = {}
last = {}
max = {}
min = {}
new = {}
next = {}
none = {}
off = {}
offset = {}
old = {}
on = {}
only = {}
pause = {}
prev = {}
reset = {}
resume = {}
set = {}
start = {}
stop = {}
write = {}
zero = {}
.........
.........
-- ---------------------------------------------------------------------
-- set/show sensor bias current
-- ---------------------------------------------------------------------
def_vals ["bias"] = BIAS_CURR_DEFAULT
curr_vals["bias"] = def_vals["bias"]
prev_vals["bias"] = def_vals["bias"]
min_vals ["bias"] = 0
max_vals ["bias"] = 31
function bias(new_bias)
if (not new_bias) then
-- do nothing
-- show default value
elseif (new_bias == default) then
print("Default=", def_vals["bias"])
-- reset to default value
elseif (new_bias == reset) then
prev_vals["bias"], curr_vals["bias"] =
curr_vals["bias"], def_vals["bias"]
-- restore previous value
elseif (new_bias == back) then
prev_vals["bias"], curr_vals["bias"] =
curr_vals["bias"], prev_vals["bias"]
-- set minimum value
elseif (new_bias == min) then
prev_vals["bias"], curr_vals["bias"] =
curr_vals["bias"], min_vals["bias"]
-- set maximum value
elseif (new_bias == max) then
prev_vals["bias"], curr_vals["bias"] =
curr_vals["bias"], max_vals["bias"]
-- set given value
else
prev_vals["bias"], curr_vals["bias"] =
curr_vals["bias"], new_bias
end
-- set current level even when not changed.
set_bias_current(curr_vals["bias"])
print("Bias current set to: ", curr_vals["bias"])
end