LuaJIT 3.0 proposed syntax extensions(github.com) |
LuaJIT 3.0 proposed syntax extensions(github.com) |
Does that operator compile to faster assembly that if I make the same logic with verbose `if` logic? Is that a language specific outcome?
local x = condition ? value_a : value b
local x = condition and value_a or value_b> E.g. true and false or 42 returns 42, whereas true ? false : 42 returns the (expected) false.
Some of these really look like QoL improvements. I'm not convinced ternary statements are an ergonomic improvement in particular. The examples given don't make a compelling case, 'visually tidy' is not the same as readable.
There are real improvements though, such as ?. and ??= that help with default-nullable everything.
Ternary is very useful, but it I'd rather see it implemented idiomatically:
pos += (if forward then +1 else -1)
A lot of these changes make sense (although some of them are a bit too TIMTOWTDI for my taste) - but perhaps LuaJIT 3 would benefit from a change of name as well? Certainly with all these changes, it would be more like a separate language than merely a JIT-compiled version of Lua.
What on earth is this supposed to mean?
That takes me back a bit. It's a perl-ism. I used to think it was a great design feature but I've come to strongly prefer "There should be one way to do it, and it should be obvious"
https://www.lua.org/versions.html#5.3
https://www.lua.org/manual/5.3/manual.html#3.4.2
Looks like LuaJIT is catching up, but calling these "syntax extensions" is confusing. Is the intent to hold LuaJIT fixed against some earlier Lua version (I guess 5.1) and adopt newer syntax piecemeal?
I welcome the compound assignment operators. Playdate's version of Lua also has that extension.
My ultimate goal was to support LuaJIT in Rust as well but this does not make it easier.
So shouldn't it have a new name?
Personally im a fan of introducing ternaranary operator in lua. Everyone uses `x and y or z` as a ternanary which i find way more confusing than ?:
But which Lua?
Lua as implemented by LuaJIT is a fork of the language at this point. It's not fully compatible with PUC Lua (the reference implementation) and LuaJIT does not support features from the latest Lua version.
Edit: meaning he can come back anytime.
Likewise, going from `and` and `or` to `&&` and `||` would be a dispiriting regression. This is something that Zig got right.
Also, I love this kind of pragmatism:
> Exponentiation assignment a ^= b has been deliberately omitted to avoid a predictable pitfall: this is how xor assignment is written in most other computer languages. Also, a syntax for exponentiation assignment is rarely asked for.
A ‘defer’ for closing files or deleting temp files at the end of a script will make life more enjoyable.
1) Ease of learning, ideally minimal deviant behaviour (eg i consider lua tables to be a new concept in itself)
2) Reasonably fast. Not as much as lua jit but even half would be good enough
3) Mature
4) Has Rust bindings
cond1 ? res1 :
cond2 ? res2 :
cond3 ? res3 :
or_else_res
Right now, `if` in expression position is just a syntax error ("unexpected symbol")