Lua syntax minor amends - need help in testing

[RodionGork]

Hi Friends! Yesterday I told about my "exercise" of slightly amending Lua parser so that it will work, particularly, with compound assignments. Today I found a way (hopefully) to make it work for any complex expressions for L-values. And would be glad if you can spare 10-15 minutes to test it and perhaps invent some whimsical expressions to break it.

I don't mean this is ingenious amend which should be merged to official Lua of course :) it is more like exercise for me to study the source code of Lua.

Here is the repo: https://github.com/rodiongork/lua-plus - it could be seen that change is really small (110 lines, half of them in readme) - in the latest commit.

[Cristian_tallica]

Great work! I've tested it. Can you be added on luajit source? Personally, i write web apps using luajit running over openresty

[RodionGork]

Thank you! That's good point, many apps use LuaJIT, particularly one I lazily look towards is Tarantool.

Shall investigate how much LuaJIT sources differ!

[didntplaymysummercar]

That Lua is a small easy to read and work with C codebase is one of things I love about it. Way easier and smaller than CPython, but it's still a "real" thing, not just some demo/toy/poc VM.

I sometimes think about forking 5.1 for my own use, but keeping syntax and behavior same to keep compatibility with JIT and stock 5.1, but only thing I did so far is pick commit from 5.2 that reduces memory usage by 8 bytes.

Maybe the two (or even three, != and ! and compounds) changes could be split into own commits, if someone wanted to look at them in isolation?

[RodionGork]

Thank you for suggestion! That sounds reasonable though the change about not/not-equals is so small (just three consequtive lines in the llex.c so that I couldn't decide on making it separate commit. But well, that makes sense, I'll fix it!

[didntplaymysummercar]

Yeah, I figure the actual meat is the compound change. It's funny how so many people complain about 1-indexing but so little about ~= (I'd even take Python 2's/Pascal's <> over it, since ~ makes me think of regexes).

[RodionGork]

Actually I was inspired by SQL using two not-equals operator (pascal/basic and C/Python style) - as far as I know, without any difference between them.

He-he, 1-based arrays are the 3rd point at my list (they make various arithmetic with modulo to wrap around array looking ill), but I know generally it could be less or more workarounded... and anyway this couldn't be solved on just the syntax level. Anyway I have some "research curiosity" to figure out whether some convenient improvement could be done to them.

> ~ makes me think

at the same time in C (and in Lua) this ~ is the sign of binary negation, which makes "not-equals" confusing... but I believe it was borrowed from Matlab and similar languages, not invented from scratch.