the existing # operator about lua-resty-redis

[agentzh]

@aCayF Or just use the "n" variable name. Patches welcome!

[agentzh]

@aCayF Okay, it seems that the "limit" condition in the loop for i = 1, limit is only evaluated once, according to the official Lua language manual:

http://www.lua.org/manual/5.1/manual.html#2.4.5

So the # operator will not be re-evaluated upon every loop iteration. So we're fine here. No patch is needed.

[aCayF]

if i didn't misunderstand anything, i think the overhead eliminated by the #22 is re-hashing table when using table.insert and evaluating # operator appeared in the loop block every loop iteration

[agentzh]

@aCayF Nah, table.insert does not always rehash the table. Its behavior is similar to tb[i] = v but it always invokes lj_tab_len on the table, which is called by the # operator too. So essentially we are saving the overhead in lj_tab_len upon every table insertion here.

In #22, the # operator is called by every loop iteration but in the limit part of the loop for i = 1, limit, it is called only once upon the loop entry.

[aCayF]

Thank you for the information :)