Hand written recursive descent and non-backtracking parsing "combinator" library designed with nice error in mind and lossless data.
Use cargo-edit:
sh
cargo add alder
Or add it manually:
toml
alder = "0.2.0"
You may want to enable a derive feature as well:
toml
alder = { version = "0.2.0" , features = ["derive"] }
``rust
// Doc tests are treated as a test cases for snapshots.
// To enable them usederivefeature and add#[alder_test]` macro.
// It also supports /* multiline comments */
/// []
/// [true]
/// [true,false]
/// [ ]
/// [ true ]
/// [ true, false ]
/// [ true, false, ]
/// [trua, falsa]
/// [truadsadsa, falsa]
/// [true, false
/// [truad sadsa, falsa]
/*
[
true,
false,
"foo"
]
*/
fn array() -> impl Parser {
// withextra injects whitespace parser before and after every token.
// Unless you explicitly told parser not to do it (for example in strings).
withextra(ws(), node(Json::Array, |state| {
state.add(token('['));
match state.input.peek() {
Some(']') => (),
_ => 'outer: loop {
state.add(value());
'inner: loop { // Until we find either ']' or ','
match state.input.peek() {
Some(']') => {
break 'outer;
}
Some(',') => {
// If there was a problem and we find , we try to process rest of the array normally.
state.add(recover(token(',')));
// Trailing comma
if let Some(']') = state.input.peek() {
break 'outer;
}
break 'inner;
},
// EOF
None => {
state.add(raise(Problem::InvalidTokenArray, 1));
break 'outer;
},
_ => state.add(raise(Problem::InvalidTokenArray, 1)),
};
}
},
}
state.add(recover(token(']')));
}))
} ```
Parsers should return information about what happened and where it happened:
``
--------------------------------- SYNTAX ERROR ---------------------------------
I was parsing Boolean when found issue:
0 |[truadsadsa, falsa]\EOF
~ | ^^^^^^^^^^ I expectedtrue`
--------------------------------- SYNTAX ERROR ---------------------------------
I was parsing Boolean when found issue:
0 |[truadsadsa, falsa]\EOF
~ | ^^^^^ I expected false
```