Yeah, Lua is really nice. It’s also fast and small. In fact, “Programming in Lua” is imo one of the best programming language books available, up there with Kernighan and Richie’s “The C Programming Language.”
Yes, I was shocked at how small it is. I had no experience working with such limited resources going into this project. Our router had 32MB of storage. At one point I was looked into adding a python interpreter, and it was like 11MB. The Lua interpreter is like 250KB. Tiny!
Also, the ternary operator has the best syntax of any language I have ever used.
x = [condition] and [true value] or [false value]
No question marks or colons or anything weird. It’s a logical extension of && and || after commands in bash using keywords since it is a verbose language. I wish every language had this syntax.
For contrast, python is:
x = [true value] if [condition] else [false value]
It just seems weird to me to have the condition in the middle.
Yeah, I’ve always hated Python’s ternary, and I use it every day at work. Though you can do the same in Python if you want:
x = [condition] and [true value] or [false value]
I consider that bad style because the dedicated syntax is preferred. You can also do similar in JS:
x = [condition] && [true value] || [false value]
The caveat in both (and Lua) is that you’ll get the false value if the true value is falsey.
My favorite syntax is Rust:
x = if [condition] { [true value] } else { [false value] };
This preserves the flow you get with the ? :, allows [true value] to be falsey, and is idiomatic without having a lot of extra syntax.
My favorite thing about Lua is that tables separate numeric from string keys, so you can do this:
x = { metadata = ... }
x[1] = 3
x[2] = 4
print(#x) -- prints 2
This is really nice for representing something like an XML/HTML DOM, where numeric indices are child nodes, and string keys are attributes. Or you can store metadata about a list in the list itself (e.g. have a reference to the max value, min value, etc). It’s just really nice to work with.
Yeah, Lua is really nice. It’s also fast and small. In fact, “Programming in Lua” is imo one of the best programming language books available, up there with Kernighan and Richie’s “The C Programming Language.”
Yes, I was shocked at how small it is. I had no experience working with such limited resources going into this project. Our router had 32MB of storage. At one point I was looked into adding a python interpreter, and it was like 11MB. The Lua interpreter is like 250KB. Tiny!
Also, the ternary operator has the best syntax of any language I have ever used.
x = [condition] and [true value] or [false value]No question marks or colons or anything weird. It’s a logical extension of
&&and||after commands in bash using keywords since it is a verbose language. I wish every language had this syntax.For contrast, python is:
x = [true value] if [condition] else [false value]It just seems weird to me to have the condition in the middle.
Yeah, I’ve always hated Python’s ternary, and I use it every day at work. Though you can do the same in Python if you want:
I consider that bad style because the dedicated syntax is preferred. You can also do similar in JS:
The caveat in both (and Lua) is that you’ll get the false value if the true value is falsey.
My favorite syntax is Rust:
This preserves the flow you get with the
? :, allows [true value] to be falsey, and is idiomatic without having a lot of extra syntax.My favorite thing about Lua is that tables separate numeric from string keys, so you can do this:
This is really nice for representing something like an XML/HTML DOM, where numeric indices are child nodes, and string keys are attributes. Or you can store metadata about a list in the list itself (e.g. have a reference to the max value, min value, etc). It’s just really nice to work with.
Haskell’s
ifis pretty nice:if cond then truthy else falsy