rl_lang/checker/
structs.rs

1//! Core data structures for the type checker.
2//!
3use std::{
4    collections::{HashMap, HashSet},
5    path::PathBuf,
6};
7
8use crate::{
9    ast::{Ast, statements::TypeAnnotation},
10    interpreter::native::Module,
11    utils::{errors::Error, source::SourceFile, span::Span},
12};
13
14/// The stateful type checker, threaded through the entire AST walk.
15pub struct TypeChecker {
16    /// Stack of scopes, each mapping variable/function names to their [`ScopeItem`].
17    pub scopes: Vec<HashMap<String, ScopeItem>>,
18    /// Source file attached for Ariadne error rendering; `None` in LSP-less contexts.
19    pub source_file: Option<SourceFile>,
20    /// The stdlib module tree, used to resolve stdlib call paths.
21    pub root_module: Module,
22    /// All type errors accumulated during the check pass.
23    pub errors: Vec<Error>,
24    /// Stack of expected return types, pushed/popped on function and lambda entry/exit.
25    pub return_type_stack: Vec<TypeAnnotation>,
26    /// Nesting depth of loops - used to validate `break` and `continue`.
27    pub loop_depth: u32,
28    /// Flat set of all stdlib function names for fast single-name lookup.
29    pub stdlib_fn_names: std::collections::HashSet<String>,
30    /// `(span, markdown)` pairs collected at every declaration and usage site,
31    /// consumed by the LSP hover provider.
32    pub hovers: Vec<(Span, String)>,
33    pub base_dir: Option<PathBuf>,
34    pub importing: Vec<PathBuf>,
35    pub imported: HashSet<PathBuf>,
36    pub ast_arena: Ast,
37    /// Maps `record` type names to their declared `(field name, field type)` list.
38    pub records: HashMap<String, Vec<(String, TypeAnnotation)>>,
39    /// Maps `tag` (enum) type names to their declared variant name list.
40    pub tags: HashMap<String, Vec<String>>,
41}
42
43/// A single entry in a type checker scope.
44pub struct ScopeItem {
45    /// The static type of this variable or function.
46    pub type_annotation: CheckType,
47    /// Whether this binding is immutable (`CONST`).
48    pub is_const: bool,
49}
50
51/// The type of a value as seen by the static checker.
52#[derive(Debug, Clone, PartialEq)]
53pub enum CheckType {
54    /// A fully resolved type (e.g. `int`, `arr[string]`).
55    Known(TypeAnnotation),
56    /// A function type with known parameter and return types.
57    Function {
58        params: Vec<TypeAnnotation>,
59        return_type: TypeAnnotation,
60    },
61    /// Type could not be determined statically (stdlib calls, unresolved names).
62    /// Propagates silently to avoid cascading false errors.
63    Unknown,
64}
rl_lang/checker/structs.rs

rl_lang/checker/
structs.rs
