Re: share a stupid typo bug of me :(

[Egor Skriptunoff <egor.skriptunoff@...>]

Similar names "gsub" and "sub" leads to mistakes for almost every Lua coder.
I'd prefer them to be renamed to more univocal "grepl" and "part".
And leave "sub" for "subtraction" :-)

On 11/3/12, Xavier Wang <weasley.wx@gmail.com> wrote:
> Hi list,
>
> this morning I'm writing a Lua script converting UnicodeData.txt from
> unicode.org to a C file, just like the one slnunicode used. I just
> want to refactor slnunicode, make it simpler, smaller and fit Lua 5.2.
>
> After dig enough information from text database,  I use a variable
> "line" to contain a line ready to write to C file, just like this:
>
> ----------------
> local line = "    "
> local lastv
> for i, v in ipairs(pages) do
>     --io.write("page["..i.."] = {"..table.concat(v, ", ").."}\n")
>     if i == lastpage+1 then
>         io.write(line:gsub(1, -3), "\n")
>         line = "    ,"
>         io.write "#if UTF_MAX > 3\n"
>     end
>     for _, v in ipairs(v) do
>         line = line .. (v-1) .. ", "
>         if #line > 70 then
>             io.write(line:sub(1, -2), "\n")
>             line = "    "
>         end
>     end
>     lastv = v
> end
> io.write(line:sub(1, -3), "\n")
> io.write [[
> #endif /* UTF_MAX > 3 */
> };
> ]]
>
> -------------------
>
> just a part of script, did you see the issue in it? I don't. I just
> find, all output data are correct, except the one above "#if UTF_MAX
>>3" line -- some group index turned to negative number!!
>
> So I find in the algorithm to detect whether something I made it
> wrong, but no luck, I tried every thing I have thought, but no lucky.
> just the moment my computer get sucks, it run out all memory (4G) but
> taskmgr.exe tell me no program use many memory.... sigh, so I guess
> it's something wrong in Emergency garbage collector, so I close my
> computer and going to sleep.
>
> After a enough sleep (waked up my be girlfriend's call), I'm trying
> again to find out the issue. I boot my computer and everything the
> same, so it can't the issue of garbage collector, so I copy code to a
> fresh Lua script, and try to analyze it. it just output negative
> number as the same. at last I try to write a small script only output
> one line: it works! so it's the time to compare the two version of
> snippet...
>
> OH MY GOD!!!!
>
> Yes, maybe you have found out the answer. there is nothing wrong with
> my algorithm, nothing wrong with pretty print loop, the issue is just,
> I need use "sub" on line, but not "*g*sub"!!
>
> God bless coders stay up all night T-T
>
> the lesson I have learned:
> - Don't make simple thing complicate.
> - go to bed and have a *good* sleep before you work.
> - hi Roberto, when can we disable Auto Coercion? (Yes I know it's all
> my bad, but make a Lua don't have auto coercion will make life easy)
>
> Thanks for everybody interesting my unfortunate accident :-) God bless you!
>
> --
> regards,
> Xavier Wang.
>
>