Forum Discussion
Rory_Hewitt_139
Nimbostratus
NimbostratusDetermining processing based on flags in a URL
I have a URL which will come in as
/features?features=10010001
where each '1' or '0' is a 'flag'. I need to check each flag in turn and depending on its value, XOR it with a matching flag s...
that kinda works, except that the characters could potentially be 0, 1 or -
may we remove - before scanning?
% scan [string map {"-" ""} 10--01-00---01] %2d%2d%2d%2d a b c d 4 % put "$a $b $c $d" 10 1 0 1by the way, if flag is only one digit each, can we use split?
% split [string map {"-" ""} 10--01-00---01] {} 1 0 0 1 0 0 0 1
nitass_89166
Noctilucent
Noctilucentwhat about scan or regexp?
scan
% scan 10010001 %2d%2d%2d%2d a b c d
4
% put "$a $b $c $d"
10 1 0 1
% time "scan 10010001 %2d%2d%2d%2d a b c d" 1000
5.319 microseconds per iteration
regexp
% regexp {(\d\d)(\d\d)(\d\d)(\d\d)} 10010001 m a b c d
1
% put "$a $b $c $d"
10 01 00 01
% time "regexp {(\d\d)(\d\d)(\d\d)(\d\d)} 10010001 m a b c d" 1000
3.077 microseconds per iteration
Rory_Hewitt_139Hey @nitass, that kinda works, except that the characters could potentially be 0, 1 or -, so I can't use %d in scan or \d in regex. I can use %c in scan, but it converts them to a Unicode integer. So for instance, scan $flags %c%c%c%c%c%c%c%c flag1 flag2 flag3 flag4 flag5 flag6 flag7 flag8 gives me "49 45 48 45 45 45 45 49". Any way to simply chop them out as single characters?
JGCumulonimbus
The test results here seem to go contrary to the prevalent view that prefers "scan" to "regexp" for performance.