mist-parser 0.1.1

use crate::{
    Rule,
    ast::*,
    ast_expr,
    error::{AstError, AstResult, IntoErr, collect_recovered},
    parser::{consume_rule, listen_rule},
};

impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for FunctionDecl {
    type Error = AstError<'a, Self>;

    fn try_from(pair: pest::iterators::Pair<'a, Rule>) -> Result<Self, Self::Error> {
        let mut inner = pair.into_inner();
        let visibility = Visibility::try_from(&mut inner);
        let return_type = TypeExpr::try_from(inner.next().unwrap());
        let name = Identifier::try_from(inner.next().unwrap());

        let generics = consume_rule(&mut inner, Rule::generics)
            .map(Generics::try_from)
            .transpose()
            .map(|v| v.unwrap_or_default());

        let self_param = consume_rule(&mut inner, Rule::self_param).map(|param| {
            let mut param_inner = param.into_inner();
            let name = Pattern::Id(Identifier(String::from("self")));

            let mutable = listen_rule(&mut param_inner, Rule::mutable);

            let is_ref = listen_rule(&mut param_inner, Rule::deref_px);

            VarDecl {
                mutable: mutable && !is_ref,
                name: name.clone(),
                type_: Some(TypeExpr(
                    TypeExprKind::Path(Path(vec![Identifier("Self".to_string())])),
                    if is_ref {
                        vec![if mutable {
                            TypePostfix::RefMut
                        } else {
                            TypePostfix::Ref
                        }]
                    } else {
                        Vec::new()
                    },
                )),
            }
        });

        let params = consume_rule(&mut inner, Rule::param_list)
            .map({
                let self_param = self_param.clone();
                |params_pair| -> AstResult<'a, ParamList> {
                    let mut params = ParamList::try_from(params_pair)?;
                    if let Some(x) = self_param {
                        params.0.insert(0, x);
                    }
                    Ok(params)
                }
            })
            .unwrap_or_else(|| Ok(ParamList(self_param.into_iter().collect())));

        let body = inner.next().map(Block::try_from).transpose();

        ast_expr!(Self {
            visibility: visibility,
            return_type: return_type,
            name: name,
            generics: generics,
            params: params,
            body: body,
        })
    }
}

impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for ParamList {
    type Error = AstError<'a, Self>;

    fn try_from(pair: pest::iterators::Pair<'a, Rule>) -> Result<Self, Self::Error> {
        Ok(ParamList(collect_recovered(pair.into_inner()).get()?))
    }
}