hax_rust_engine/
printer.rs

1//! Printer infrastructure: allocators, traits, and the printing pipeline.
2//!
3//! This module contains the common plumbing that backends and printers rely on
4//! to turn AST values into formatted text:
5//! - [`Allocator`]: a thin wrapper around the `pretty` crate's allocator,
6//!   parameterized by the backend, used to produce [`pretty::Doc`] nodes.
7//! - [`PrettyAst`]: the trait that printers implement to provide per-type
8//!   formatting of Hax AST nodes (re-exported from [`pretty_ast`]).
9//! - The resugaring pipeline: a sequence of local AST rewrites that make
10//!   emitted code idiomatic for the target language before pretty-printing.
11
12use std::ops::Deref;
13
14use crate::{
15    ast::{self, span::Span},
16    attributes::LinkedItemGraph,
17    printer::pretty_ast::ToDocument,
18};
19use ast::visitors::dyn_compatible;
20
21pub mod pretty_ast;
22pub use pretty_ast::PrettyAst;
23
24pub mod render_view;
25
26/// A resugaring is an erased mapper visitor with a name.
27/// A resugaring is a *local* transformation on the AST that produces exclusively `ast::resugared` nodes.
28/// Any involved or non-local transformation should be a phase, not a resugaring.
29///
30/// Backends may provide **multiple resugaring phases** to incrementally refine
31/// the tree into something idiomatic for the target language (e.g., desugaring
32/// pattern sugar into a more uniform core, then resugaring back into target
33/// idioms). Each phase mutates the AST in place and should be small, focused,
34/// and easy to test.
35///
36/// If you add a new phase, make sure it appears in the backend’s
37/// `resugaring_phases()` list in the correct order.
38pub trait Resugaring: for<'a> dyn_compatible::AstVisitorMut<'a> {
39    /// Get the name of the resugar.
40    fn name(&self) -> String;
41}
42
43/// A printer defines a list of resugaring phases.
44pub trait Printer: Sized + PrettyAst<Span> + Default + HasLinkedItemGraph {
45    /// A list of resugaring phases.
46    fn resugaring_phases() -> Vec<Box<dyn Resugaring>>;
47    /// The name of the printer
48    const NAME: &'static str = <Self as PrettyAst<Span>>::NAME;
49}
50
51/// Getter and setter for `LinkedItemGraph`, useful for printers.
52pub trait HasLinkedItemGraph {
53    /// Get a reference of the `LinkedItemGraph`.
54    fn linked_item_graph(&self) -> &LinkedItemGraph;
55    /// Set a `LinkedItemGraph`.
56    fn with_linked_item_graph(self, graph: std::rc::Rc<LinkedItemGraph>) -> Self;
57}
58
59/// Placeholder type for sourcemaps.
60pub struct SourceMap;
61
62/// Helper trait to print AST fragments.
63pub trait Print<T>: Printer {
64    /// Print a single AST fragment using this backend.
65    fn print(&mut self, mut fragment: T) -> (String, SourceMap)
66    where
67        T: ToDocument<Self, Span>,
68        // The following node is equivalent to "T is an AST node"
69        for<'a> dyn Resugaring: dyn_compatible::AstVisitableMut<'a, T>,
70    {
71        for mut reguaring_phase in Self::resugaring_phases() {
72            reguaring_phase.visit(&mut fragment)
73        }
74        let doc_builder = fragment.to_document(self).into_doc();
75        (doc_builder.deref().pretty(80).to_string(), SourceMap)
76    }
77}
78impl<P: Printer, T> Print<T> for P {}
hax_rust_engine/printer.rs

hax_rust_engine/
printer.rs
