rill_lang/
ast.rs

1//! Abstract syntax tree produced by the parser.
2
3use crate::error::Span;
4
5/// Binary block-diagram combinators and arithmetic operators.
6#[derive(Debug, Clone, Copy, PartialEq, Eq)]
7pub enum BinOp {
8    /// `:` sequential composition.
9    Seq,
10    /// `,` parallel composition.
11    Par,
12    /// `<:` split / fan-out.
13    Split,
14    /// `:>` merge / fan-in.
15    Merge,
16    /// `~` feedback (implicit 1-sample delay).
17    Feedback,
18    /// `@` integer delay.
19    Delay,
20    /// `+`
21    Add,
22    /// `-`
23    Sub,
24    /// `*`
25    Mul,
26    /// `/`
27    Div,
28    /// `%`
29    Rem,
30}
31
32/// A rill-lang expression node.
33#[derive(Debug, Clone, PartialEq)]
34pub enum Expr {
35    /// Integer literal.
36    Int(i64, Span),
37    /// Float literal.
38    Float(f64, Span),
39    /// Identity wire `_` (arity 1→1).
40    Wire(Span),
41    /// Cut `!` (arity 1→0).
42    Cut(Span),
43    /// String literal, e.g. `"cutoff"`.
44    Str(String, Span),
45    /// A reference to a definition or a bound parameter.
46    Ref(String, Span),
47    /// Application `name(arg, ...)`.
48    Apply {
49        /// Function name.
50        name: String,
51        /// Argument expressions.
52        args: Vec<Expr>,
53        /// Full span of the application.
54        span: Span,
55    },
56    /// Unary negation `-expr`.
57    Neg(Box<Expr>, Span),
58    /// A binary combinator/operator.
59    Bin {
60        /// The operator.
61        op: BinOp,
62        /// Left operand.
63        lhs: Box<Expr>,
64        /// Right operand.
65        rhs: Box<Expr>,
66        /// Full span.
67        span: Span,
68    },
69}
70
71impl Expr {
72    /// The source span of this node.
73    pub fn span(&self) -> Span {
74        match self {
75            Expr::Int(_, s)
76            | Expr::Float(_, s)
77            | Expr::Wire(s)
78            | Expr::Cut(s)
79            | Expr::Str(_, s)
80            | Expr::Ref(_, s)
81            | Expr::Neg(_, s) => *s,
82            Expr::Apply { span, .. } | Expr::Bin { span, .. } => *span,
83        }
84    }
85}
86
87/// A top-level definition: `name(params) = body;` (params may be empty).
88#[derive(Debug, Clone, PartialEq)]
89pub struct Def {
90    /// Definition name.
91    pub name: String,
92    /// Formal parameter names (empty for a plain alias).
93    pub params: Vec<String>,
94    /// Right-hand side.
95    pub body: Expr,
96    /// Span of the whole definition.
97    pub span: Span,
98}
99
100/// A whole program: an ordered list of definitions. One MUST be named `process`.
101#[derive(Debug, Clone, PartialEq)]
102pub struct Program {
103    /// The definitions in source order.
104    pub defs: Vec<Def>,
105}
rill_lang/ast.rs

rill_lang/
ast.rs
