yog_script_analyze/ast/
pattern.rs

1//! Patterns (`ys-grammar.md` §3.3) and types (§4).
2
3use super::{BinOp, Expr, Name};
4use crate::source::token::Span;
5
6#[derive(Debug, Clone, PartialEq)]
7pub enum Pattern {
8    Wild(Span),
9    /// A literal or a path to a value or a case (`0`, `Mode.Idle`); a
10    /// lone path may be a type too: the resolver and the checker tell.
11    Value(Expr),
12    /// `let e`.
13    Let(Name),
14    /// `Monster m`, `Monster`.
15    Type {
16        ty: Type,
17        bind: Option<Name>,
18    },
19    /// `Mode.Charging(let rate)`.
20    Variant {
21        path: Vec<Name>,
22        args: Vec<Pattern>,
23    },
24    /// `< 5`.
25    Relational {
26        op: BinOp,
27        value: Expr,
28    },
29    Range {
30        from: Expr,
31        to: Expr,
32    },
33    Tuple(Vec<Pattern>),
34    /// `[1, let second, .., let last]` (C#'s list pattern): an array's, a
35    /// string's or a list's items, a `..` among them at most once.
36    List(Vec<Pattern>, Span),
37    /// `..` in a list pattern: the items it doesn't name, `.. let rest`
38    /// matching them as a slice.
39    Slice(Option<Box<Pattern>>),
40    /// `{ Health: < 5 }`, `Monster { Health: < 5 }`.
41    Property {
42        ty: Option<Type>,
43        fields: Vec<(Name, Pattern)>,
44    },
45    Or(Box<Pattern>, Box<Pattern>),
46    And(Box<Pattern>, Box<Pattern>),
47    Not(Box<Pattern>),
48}
49
50#[derive(Debug, Clone, PartialEq)]
51pub struct Type {
52    pub kind: TypeKind,
53    pub span: Span,
54}
55
56#[derive(Debug, Clone, PartialEq)]
57pub enum TypeKind {
58    /// `i32`, `List<T>`, `Mode.Charging`.
59    Path {
60        path: Vec<Name>,
61        args: Vec<Type>,
62    },
63    /// `(i32 X, i32 Y)`.
64    Tuple(Vec<(Type, Option<Name>)>),
65    Nullable(Box<Type>),
66    /// `T[]`, `T[,]` (`rank` 2), `T[][]` (an array of `T[]`).
67    Array {
68        item: Box<Type>,
69        rank: usize,
70    },
71    /// `Charge & Owned`.
72    Both(Vec<Type>),
73    /// `in 'a T`, `ref 'a T`: a borrow (Rust's `&'a T`, `&'a mut T`).
74    Borrow {
75        mutable: bool,
76        lifetime: Option<Name>,
77        ty: Box<Type>,
78    },
79    /// `'a` among a type's arguments (`Cursor<'a>`).
80    Lifetime(Name),
81}
yog_script_analyze/ast/pattern.rs

yog_script_analyze/ast/
pattern.rs
