A lifetime error while copying nano_rs.rs example code

[chiichen]

I am trying to copy the nano_rs.rs example code into my workspace using 1.0.0-alpha6. But it leads to a lifetime error

error: lifetime may not live long enough
   --> src/parser/chumsky_parser/nano_rs.rs:206:5
    |
200 |   fn expr_parser<'tokens, 'src: 'tokens>() -> impl Parser<
    |                  -------  ---- lifetime `'src` defined here
    |                  |
    |                  lifetime `'tokens` defined here
...
206 | /     recursive(|expr| {
207 | |         let inline_expr = recursive(|inline_expr| {
208 | |             let val = select! {
209 | |                 Token::Null => Expr::Value(Value::Null),
...   |
405 | |             )
406 | |     })
    | |______^ function was supposed to return data with lifetime `'src` but it is returning data with lifetime `'tokens`
    |
    = help: consider adding the following bound: `'tokens: 'src`

I am wondering if there is any other settings or features are expected to turn on in my cargo project

[zesterer]

Are you copying the example as-is? And if so, what compiler version are you using?

[chiichen]

rustup 1.26.0 (5af9b9484 2023-04-05)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.73.0-nightly (32303b219 2023-07-29)`

Yes, I just simply copy it as-is. And it seems to be okay when I create a brand new cargo project to run the code. So I think it's a kind of compiler error.I am going to test it. Thanks for your immediate answer anyway

[zesterer]

Is this still an issue for you?

[chiichen]

I've already figured out that this lifetime error is caused by a wrong cargo.toml file without specifying the edition like this.

[package]
name = "nano_rs"
version = "0.1.0"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
chumsky = { version = "1.0.0-alpha.6", features = ["label"] }
ariadne = "0.3.0"

But once specified edition = “2021”:

[package]
name = "nano_rs"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
chumsky = { version = "1.0.0-alpha.6", features = ["label"] }
ariadne = "0.3.0"

this error no longer occured. I'm not sure about the principle of the edition flag while compiling.But it works anyway.

Thanks for your answer

[zesterer]

Ah, good to know!