A simple framework to build compilers and interpreters
This crate requires a nightly compiler because of the try_trait_v2 feature.
As of version 0.6 requires Rust version 1.79.
use langbox::*;
enum JsonTokenKind {
// ...
}
// Make the reader an uninhabited type because we don't construct any objects of it
enum JsonTokenReader {}
impl TokenReader for JsonTokenReader {
type Token = JsonTokenKind;
fn read_token(text: &str) -> ReadTokenResult<Self::Token> {
// ...
}
}
struct JsonValue {
// ...
}
fn jvalue() -> impl Parser<JsonTokenKind, JsonValue, String> {
// ...
}
fn main() {
// FileServer manages loading files for us.
// It ensures the same physical file is never loaded twice.
let mut file_server = FileServer::new();
let file_id = file_server.register_file( /* ... */ );
// After we have loaded a file we can tokenize it using a Lexer.
type JLexer<'a> = Lexer<'a, JsonTokenReader, whitespace_mode::Remove>;
let lexer = JLexer::new(file_id, &file_server);
let tokens = lexer.collect::<Vec<_>>();
let stream = TokenStream::new(&tokens);
// Finally after all files have been tokenized we can parse the token stream.
match jvalue().run(stream).expect("malformed JSON input") {
InfallibleParseResult::Match { value, .. } => {
// `value` contains the parsed JSON value
}
InfallibleParseResult::NoMatch => { /* empty input */ }
}
}