[outdated] strcmp, or a proper operator < on strings

[merlight]

Operator < on strings in ESO-Lua ignores everything except letters and digits. It's useless for sorting strings containing spaces and/or punctuation, as it doesn't define a total order.

Examples:

"a" < "A" == true
"b" < "A" == false
"A" < "a" == false
"B" < "c" == true
-- interesting, the order is: "a", "A", "b", "B", "c", ...
-- that's nice, actually
 
"aa" < "A" == false
"aa" < "Aa" == true
-- more surprises, the order is: "a", "aa", "aA", "Aa", "AA", ...
-- but still fine
 
"a head" < "ahead" == false
"ahead" < "a head" == false
-- they're not equal, yet neither is less than the other
-- this is bad, table.sort will not give consistent order
 
"#" < "~" == false
"~" < "#" == false
-- it doesn't compare the characters at all

[CrazyDutchGuy]

I assume the sorting is based on type, then the order with base 36 as next
0123456789abcdefghijklmnopqrstuvwxyz, if they are equal then sorting is based on case ?

comparing other values would likely produce a nil value as it can't convert it to a number for comaprison, which leads to a nil, which leads to type inequality, which leads to false, if it all makes sense somehow
"a head" < "ahead" == false --> nil < 17607829
"ahead" < "a head" == false --> 17607829 < nil

Anyways, it looks weird :P
aa == 370 -> (36^1)*10 + (36^0)*10
aaa == 13330 -> (36^2)*10 + aa
and so on ...

[merlight]

Originally Posted by CrazyDutchGuy I assume the sorting is based on type, then the order with base 36 as next 0123456789abcdefghijklmnopqrstuvwxyz, if they are equal then sorting is based on case ? comparing other values would likely produce a nil value as it can't convert it to a number for comaprison, which leads to a nil, which leads to type inequality, which leads to false, if it all makes sense somehow

The default operator < in Lua requires that both operands are of the same type:
http://www.lua.org/source/5.1/lvm.c.html#luaV_lessthan

Strings are compared using strcoll:
http://www.lua.org/source/5.1/lvm.c.html#l_strcmp

What we have in ESO is some custom-made string comparison. Perhaps it supports multi-byte UTF-8 characters, I haven't checked that. It doesn't support ASCII punctuation, that's broken enough in my eyes