use enumset::{EnumSet, EnumSetType};

pub struct Input<'src, 'toks, SyntaxKind: EnumSetType + Into<rowan::SyntaxKind>> {
    raw: &'toks Vec<(SyntaxKind, &'src str)>,
    // enumset of meaningless tokens
    semantically_meaningless: EnumSet<SyntaxKind>,
    // indices of non-meaningless tokens
    meaningful_toks: Vec<usize>,
}

impl<'src, 'toks, SyntaxKind: EnumSetType + Into<rowan::SyntaxKind>>
    Input<'src, 'toks, SyntaxKind>
{
    pub fn new(
        raw_toks: &'toks Vec<(SyntaxKind, &'src str)>,
        meaningless: Option<EnumSet<SyntaxKind>>,
    ) -> Self {
        let mut meaningful_toks = Vec::new();

        if let Some(meaningless) = meaningless {
            let meaningful_toks = raw_toks
                .iter()
                .enumerate()
                .filter_map(|(i, tok)| (!meaningless.contains(tok.0)).then_some(i))
                .collect_into(&mut meaningful_toks);
        }

        Self {
            raw: raw_toks,
            semantically_meaningless: meaningless.unwrap_or_default(),
            meaningful_toks,
        }
    }
}