mist_parser/parser/items/
function.rs

1use crate::{
2    Rule,
3    ast::*,
4    ast_ensure, ast_expr,
5    error::{AstError, AstResult, IntoErr, collect_recovered},
6    parser::{consume_rule, listen_rule},
7};
8
9impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for FunctionDecl {
10    type Error = AstError<'a, Self>;
11
12    fn try_from(pair: pest::iterators::Pair<'a, Rule>) -> Result<Self, Self::Error> {
13        ast_ensure!(pair, Rule::function_decl => {
14        let mut inner = pair.into_inner();
15            let visibility = Visibility::try_from(&mut inner);
16            let return_type = TypeExpr::try_from(inner.next().unwrap());
17            let name = Identifier::try_from(inner.next().unwrap());
18
19            let generics = consume_rule(&mut inner, Rule::generics_decl)
20                .map(GenericsDecl::try_from)
21                .transpose()
22                .map(|v| v.unwrap_or_default());
23
24            let self_param = consume_rule(&mut inner, Rule::self_param).map(|param| {
25                let mut param_inner = param.into_inner();
26                let mutable = listen_rule(&mut param_inner, Rule::mutable);
27                let is_ref = listen_rule(&mut param_inner, Rule::deref_px);
28                let name = Pattern::Path(mutable && !is_ref, Path(vec![Identifier(String::from("self"))]));
29
30                VarDecl {
31                    name: name.clone(),
32                    type_: Some(TypeExpr(
33                        TypeExprKind::Path(Path(vec![Identifier("Self".to_string())]), None),
34                        if is_ref {
35                            vec![if mutable {
36                                TypePostfix::RefMut
37                            } else {
38                                TypePostfix::Ref
39                            }]
40                        } else {
41                            Vec::new()
42                        },
43                    )),
44                }
45            });
46
47            let params = consume_rule(&mut inner, Rule::param_list)
48                .map({
49                    let self_param = self_param.clone();
50                    |params_pair| -> AstResult<'a, ParamList> {
51                        let mut params = ParamList::try_from(params_pair)?;
52                        if let Some(x) = self_param {
53                            params.0.insert(0, x);
54                        }
55                        Ok(params)
56                    }
57                })
58                .unwrap_or_else(|| Ok(ParamList(self_param.into_iter().collect())));
59
60            let body = inner.next().map(Block::try_from).transpose();
61
62            ast_expr!(Self {
63                visibility: visibility,
64                return_type: return_type,
65                name: name,
66                generics: generics,
67                params: params,
68                body: body,
69            })
70        })
71    }
72}
73
74impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for ParamList {
75    type Error = AstError<'a, Self>;
76
77    fn try_from(pair: pest::iterators::Pair<'a, Rule>) -> Result<Self, Self::Error> {
78        Ok(ParamList(collect_recovered(pair.into_inner()).get()?))
79    }
80}
mist_parser/parser/items/function.rs

mist_parser/parser/items/
function.rs
