iowo/crates/json-pawarser/src/grammar.rs

use enumset::{enum_set, EnumSet};

use crate::{syntax_error::SyntaxError, syntax_kind::SyntaxKind};

use self::object::object;

pub(crate) type Parser<'src> = pawarser::Parser<'src, SyntaxKind, SyntaxError>;
pub(crate) type CompletedMarker = pawarser::CompletedMarker<SyntaxKind, SyntaxError>;

const BASIC_VALUE_TOKENS: EnumSet<SyntaxKind> =
    enum_set!(SyntaxKind::BOOL | SyntaxKind::NULL | SyntaxKind::NUMBER | SyntaxKind::STRING);

pub fn value(p: &mut Parser) -> bool {
    if BASIC_VALUE_TOKENS.contains(p.current()) {
        p.do_bump();
        return true;
    } else {
        object(p).is_some()
    }
}

mod object {
    use crate::{grammar::value, syntax_error::SyntaxError, syntax_kind::SyntaxKind};

    use super::{CompletedMarker, Parser, BASIC_VALUE_TOKENS};

    pub(super) fn object(p: &mut Parser) -> Option<CompletedMarker> {
        let obj_start = p.start("object");

        if !p.eat(SyntaxKind::BRACE_OPEN) {
            obj_start.abandon(p);
            return None;
        }

        member(p);

        p.eat(SyntaxKind::BRACE_CLOSE);
        Some(obj_start.complete(p, SyntaxKind::OBJECT))
    }

    fn member(p: &mut Parser) -> Option<CompletedMarker> {
        let member_start = p.start("member");

        if p.at(SyntaxKind::BRACE_CLOSE) {
            member_start.abandon(p);
            return None;
        } else if p.at(SyntaxKind::STRING) {
            let member_name_start = p.start("member_name");
            p.eat(SyntaxKind::STRING);
            member_name_start.complete(p, SyntaxKind::MEMBER_NAME);
        } else {
            return todo!("handle other tokens: {:?}", p.current());
        }

        if !p.eat(SyntaxKind::COLON) {
            todo!("handle wrong tokens")
        }

        if value(p) {
            Some(member_start.complete(p, SyntaxKind::MEMBER))
        } else {
            let e = member_start.error(p, SyntaxError::MemberMissingValue);
            Some(
                e.precede(p, "member but failed already")
                    .complete(p, SyntaxKind::MEMBER),
            )
        }
    }
}
mod array {}