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AILang/crates/ailang-core/src/workspace.rs
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1205 lines
48 KiB
Rust

//! Workspace loader: loads an entry module and recursively follows its
//! `imports`.
//!
//! Convention: an `import { module: "foo" }` is resolved relative to
//! the entry file's directory as `<root_dir>/foo.ail.json`. Module
//! names must match the file stem (the loader rejects mismatches).
//!
//! The single entry point is [`load_workspace`]; it returns a fully
//! populated [`Workspace`] or a structured [`WorkspaceLoadError`].
//! [`module_hash`] is the module-granularity counterpart to
//! [`crate::def_hash`] and is used both internally (to detect a module
//! re-loaded from disk with different content) and by the CLI.
//!
//! This module is responsible only for **finding** and consistently
//! **loading** all reachable modules. Cross-module typechecking lives
//! in `ailang-check`; codegen in `ailang-codegen`. Neither is run from
//! here.
//!
//! # Examples
//!
//! ```ignore
//! use ailang_core::load_workspace;
//! use std::path::Path;
//!
//! let ws = load_workspace(Path::new("examples/ws_main.ail.json"))?;
//! assert_eq!(ws.entry, "ws_main");
//! // All transitively imported modules are now in `ws.modules`.
//! for (name, m) in &ws.modules {
//! println!("{name}: {} defs", m.defs.len());
//! }
//! # Ok::<(), ailang_core::workspace::WorkspaceLoadError>(())
//! ```
use crate::ast::{ClassDef, Def, InstanceDef, Module, Type};
use crate::canonical;
use crate::{load_module, Error as CoreError};
use std::collections::{BTreeMap, BTreeSet, HashSet};
use std::path::{Path, PathBuf};
/// Fully loaded workspace.
///
/// `entry` names the entry module (module name, **not** a path). All
/// transitively reachable modules are contained in `modules` and indexed
/// by `Module.name`. `root_dir` is the directory the entry file lives
/// in; all imports are resolved relative to it.
///
/// Iter 22b.1 (Decision 11): `registry` is the workspace-global
/// instance registry, built at the end of [`load_workspace`] after the
/// DFS over imports completes. It is empty for any workspace whose
/// modules contain no [`crate::ast::Def::Instance`] defs.
#[derive(Debug, Clone)]
pub struct Workspace {
/// Name of the entry module (the one passed to [`load_workspace`]).
pub entry: String,
/// Every module reachable from `entry`, indexed by module name.
/// `BTreeMap` is used so iteration order is deterministic, which
/// matters for downstream codegen and reporting.
pub modules: BTreeMap<String, Module>,
/// Directory the entry file lives in; all imports are resolved
/// relative to it.
pub root_dir: PathBuf,
/// Iter 22b.1: workspace-global typeclass instance registry.
pub registry: Registry,
}
/// Iter 22b.1: workspace-global instance registry (Decision 11).
///
/// Built at the end of [`load_workspace`] after all modules are
/// loaded. Keyed by `(class-name, canonical-type-hash)`; values are
/// the matching [`crate::ast::InstanceDef`] plus the name of the
/// module it was declared in. The hash key uses
/// [`canonical::type_hash`], so the key is stable against unrelated
/// whitespace / field-order differences in the source JSON.
///
/// 22b.1 enforces three coherence checks during build:
///
/// 1. **Coherence (orphan-freedom).** Every `instance C T` lives in
/// the module of `C` or in the module of `T` (per Decision 11
/// axis 3). Otherwise → [`WorkspaceLoadError::OrphanInstance`].
/// 2. **Uniqueness.** No two entries share a key. Otherwise →
/// [`WorkspaceLoadError::DuplicateInstance`].
/// 3. **Method completeness.** Each instance specifies a body for
/// every required (non-default) method of its class. Otherwise →
/// [`WorkspaceLoadError::MissingMethod`].
#[derive(Debug, Clone, Default)]
pub struct Registry {
/// Map from `(class-name, type-hash)` to the registry entry.
pub entries: BTreeMap<(String, String), RegistryEntry>,
}
/// One entry in the [`Registry`].
#[derive(Debug, Clone)]
pub struct RegistryEntry {
/// The instance declaration itself.
pub instance: InstanceDef,
/// Name of the module the instance was declared in.
pub defining_module: String,
}
/// Structured errors of the workspace loader.
///
/// `Cycle.path` is the chain of module names in which the cycle was
/// closed — the last element is the name already present in `visiting`.
#[derive(Debug, thiserror::Error)]
pub enum WorkspaceLoadError {
/// File I/O failed while reading a module file (typically: file
/// missing, permission denied).
#[error("io error for {path}: {source}")]
Io {
path: PathBuf,
#[source]
source: std::io::Error,
},
/// File contents failed to parse as a [`Module`] or had the wrong
/// schema tag. Wraps a [`CoreError`] (the single-module loader's
/// error type).
#[error("schema/parse error in {path}: {source}")]
Schema {
path: PathBuf,
#[source]
source: CoreError,
},
/// An `import { module: "foo" }` did not resolve to an existing
/// file at the expected path.
#[error("module `{name}` not found (expected at {expected_path})")]
ModuleNotFound { name: String, expected_path: PathBuf },
/// The `name` field in a loaded module file disagrees with the
/// file-stem-derived name the loader expected (i.e. the
/// `<name>.ail.json` convention is broken).
#[error(
"module name in file ({name_in_file:?}) does not match expected name from path ({name_from_path:?})"
)]
ModuleNameMismatch {
name_in_file: String,
name_from_path: String,
},
/// An import cycle was detected. `path` is the chain of module
/// names in which the cycle was closed — the last element is the
/// name that was already on the visit stack.
#[error("import cycle detected: {}", path.join(" -> "))]
Cycle { path: Vec<String> },
/// A module was reachable through two import paths, and its
/// on-disk content (compared via [`module_hash`]) differs between
/// the two reads. This typically means the file changed mid-load.
#[error(
"module `{name}` was loaded twice with differing content (hashes differ)"
)]
ModuleHashMismatch { name: String },
/// Iter 22b.1: an [`crate::ast::Def::Instance`] was declared in a
/// module that is neither the class's defining module nor the
/// instance type's defining module. Coherence violation per
/// Decision 11 axis 3 ("orphan-freedom"). The lookup is hard:
/// AILang does not provide a `--allow-orphans` flag.
#[error(
"orphan instance: `instance {class} {type_repr}` declared in module `{defining_module}`, \
but neither `{class}` (in `{class_module}`) nor `{type_repr}` (in `{type_module}`) lives there"
)]
OrphanInstance {
class: String,
type_repr: String,
defining_module: String,
class_module: String,
type_module: String,
},
/// Iter 22b.1: two [`crate::ast::Def::Instance`]s share the same
/// `(class, canonical-type-hash)` key. Coherence requires
/// uniqueness; the registry has no way to disambiguate at
/// resolution time. Per Decision 11 there is no
/// `AmbiguousInstance` diagnostic — coherence makes the lookup
/// unambiguous by construction, and a duplicate is a workspace
/// configuration error, not a per-call-site one.
#[error(
"duplicate instance: `instance {class} {type_repr}` declared in both `{first_module}` and `{second_module}`"
)]
DuplicateInstance {
class: String,
type_repr: String,
first_module: String,
second_module: String,
},
/// Iter 22b.1: an [`crate::ast::Def::Instance`] does not specify
/// a body for a required (non-default) method of its class.
/// Default-bearing methods may be inherited; non-default
/// (abstract-required) methods must be specified by every
/// instance. Per Decision 11 §"Defaults and superclasses".
#[error(
"instance `{class} {type_repr}` is missing a body for method `{method}` (no default)"
)]
MissingMethod {
class: String,
type_repr: String,
method: String,
},
/// Iter 22b.2: class-schema validation. The class parameter
/// appears in applied position (e.g. as the head of a
/// `Type::Con { name == param, args.len() > 0 }`) inside a method
/// signature. Decision 11 axis 5 forbids HKTs — class params are
/// kind `*` only.
#[error(
"kind mismatch in class `{class}`: parameter `{param}` is used in applied position \
inside method `{method}` (Decision 11 axis 5: class params are kind `*` only)"
)]
KindMismatch {
class: String,
param: String,
method: String,
defining_module: String,
},
/// Iter 22b.2: class-schema validation. A class's `superclass.type`
/// does not equal its own `param`. Decision 11 single-superclass
/// model requires the superclass to be applied to the same param
/// (e.g. `class Ord a extends Eq a`, not `extends Eq b`).
#[error(
"class `{class}` declares superclass `{superclass} {got_type}`, but its own parameter is `{expected_param}` \
— superclass `type` must equal class `param`"
)]
InvalidSuperclassParam {
class: String,
superclass: String,
expected_param: String,
got_type: String,
},
/// Iter 22b.2: class-schema validation. A class method's
/// signature contains a constraint referencing a type variable
/// that is neither bound by the method's `Forall.vars` nor equal
/// to the class's `param`.
#[error(
"in class `{class}` method `{method}`: constraint `{constraint_class} {var}` references unbound type variable `{var}`"
)]
UnboundConstraintTypeVar {
class: String,
method: String,
constraint_class: String,
var: String,
},
/// Iter 22b.2: an instance specifies a body for a method name
/// that the corresponding class does not declare. Symmetric to
/// `MissingMethod` but in the opposite direction.
#[error(
"instance `{class} {type_repr}` provides body for method `{method}`, but class `{class}` does not declare it"
)]
OverridingNonExistentMethod {
class: String,
type_repr: String,
method: String,
},
/// Iter 22b.2: a class-method name collides with another
/// class-method or with a top-level fn. `kind` is
/// `"class-class"` or `"class-fn"`.
#[error(
"method name `{method}` collides ({kind}): defined in `{first_origin}` and `{second_origin}`"
)]
MethodNameCollision {
method: String,
kind: &'static str,
first_origin: String,
second_origin: String,
},
/// Iter 22b.2: an instance `C T` was declared, but `C`'s
/// superclass `S` does not have an instance for the same type
/// `T`. Decision 11 single-superclass model requires `instance S
/// T` to exist whenever `instance C T` exists.
#[error(
"instance `{class} {type_repr}` requires superclass instance `{superclass} {type_repr}`, but none was found"
)]
MissingSuperclassInstance {
class: String,
superclass: String,
type_repr: String,
},
}
/// Hash over the canonical bytes of a complete module.
///
/// Parallel to `def_hash`, but at module level. The workspace loader
/// uses this to verify double-loads; the CLI uses it to emit a stable
/// per-module identifier.
pub fn module_hash(m: &Module) -> String {
let bytes = canonical::to_bytes(m);
let h = blake3::hash(&bytes);
h.to_hex().as_str()[..16].to_string()
}
/// Load entry module plus all transitively reachable modules.
///
/// Algorithm: DFS over `imports`, with two sets:
/// - `loaded` (= `modules` map): modules whose subtree is already fully
/// processed. On a re-hit only hash consistency is checked.
/// - `visiting`: stack of modules whose DFS descent is still running.
/// A hit here = cycle.
pub fn load_workspace(entry_path: &Path) -> Result<Workspace, WorkspaceLoadError> {
let entry_path = entry_path.to_path_buf();
let root_dir = entry_path
.parent()
.map(Path::to_path_buf)
.unwrap_or_else(|| PathBuf::from("."));
// Load entry module + check name<->filename convention.
let entry_module = load_one(&entry_path)?;
let expected_entry_name = module_name_from_path(&entry_path);
if entry_module.name != expected_entry_name {
return Err(WorkspaceLoadError::ModuleNameMismatch {
name_in_file: entry_module.name.clone(),
name_from_path: expected_entry_name,
});
}
let entry_name = entry_module.name.clone();
let mut modules: BTreeMap<String, Module> = BTreeMap::new();
let mut visiting: Vec<String> = Vec::new();
let mut visiting_set: HashSet<String> = HashSet::new();
visit(
entry_module,
&root_dir,
&mut modules,
&mut visiting,
&mut visiting_set,
)?;
// Iter 22b.2: class-schema validation runs before registry
// construction so that ill-kinded class definitions are rejected
// before any instance against them is registered.
validate_classdefs(&modules)?;
// Iter 22b.1: build the workspace-global instance registry. Three
// coherence checks fire here (Orphan / Duplicate / Missing-method);
// any violation is surfaced as a `WorkspaceLoadError`, not as a
// per-call-site diagnostic.
let registry = build_registry(&modules)?;
Ok(Workspace {
entry: entry_name,
modules,
root_dir,
registry,
})
}
/// Iter 22b.1: build the workspace-global typeclass instance registry.
///
/// Two passes:
///
/// 1. Scan every loaded module to build a "where is X defined" lookup
/// for class names and type names — needed for the coherence
/// (orphan) check below.
/// 2. For each [`crate::ast::Def::Instance`] in declaration order,
/// apply the three checks (coherence / uniqueness / method
/// completeness) and insert the entry on success.
///
/// Iteration is over the modules `BTreeMap` (alphabetical by name) so
/// the order in which collisions are detected is deterministic across
/// runs. Within a module, defs are scanned in source order.
fn build_registry(
modules: &BTreeMap<String, Module>,
) -> Result<Registry, WorkspaceLoadError> {
// Pass 1: collect "where is X defined" maps, plus a class lookup
// by name (needed for the method-completeness check).
let mut class_def_module: BTreeMap<String, String> = BTreeMap::new();
let mut type_def_module: BTreeMap<String, String> = BTreeMap::new();
let mut class_by_name: BTreeMap<String, &ClassDef> = BTreeMap::new();
for (mod_name, m) in modules {
for def in &m.defs {
match def {
Def::Class(c) => {
class_def_module.insert(c.name.clone(), mod_name.clone());
class_by_name.insert(c.name.clone(), c);
}
Def::Type(t) => {
type_def_module.insert(t.name.clone(), mod_name.clone());
}
_ => {}
}
}
}
// Iter 22b.2: method-name-collision pre-pass. Bare-name resolution
// (`foo x` rather than `A.foo x`) requires that a method name
// appears in at most one origin across the whole workspace. We
// walk every `Def::Class` and `Def::Fn` once, building a
// `method_origins` map; the first repeat fires the diagnostic.
// The `kind` field distinguishes class-method ↔ class-method from
// class-method ↔ top-level-fn; fn-fn collisions are a separate
// concern surfaced by `CheckError::DuplicateDef` in `ailang-check`,
// not here.
//
// Origins are kept structural (the `Origin` enum below) so the
// `kind` discriminator is a `match` on variants rather than a
// string-prefix check on a display form.
enum Origin {
Class { class_name: String, module: String },
Fn { name: String, module: String },
}
impl Origin {
fn format(&self) -> String {
match self {
Origin::Class { class_name, module } => {
format!("class {class_name} (in {module})")
}
Origin::Fn { name, module } => format!("fn {name} (in {module})"),
}
}
}
let mut method_origins: BTreeMap<String, Origin> = BTreeMap::new();
for (mod_name, m) in modules {
for def in &m.defs {
match def {
Def::Class(c) => {
for method in &c.methods {
let origin = Origin::Class {
class_name: c.name.clone(),
module: mod_name.clone(),
};
if let Some(prior) = method_origins.get(&method.name) {
let kind = match prior {
Origin::Class { .. } => "class-class",
Origin::Fn { .. } => "class-fn",
};
return Err(WorkspaceLoadError::MethodNameCollision {
method: method.name.clone(),
kind,
first_origin: prior.format(),
second_origin: origin.format(),
});
}
method_origins.insert(method.name.clone(), origin);
}
}
Def::Fn(f) => {
let origin = Origin::Fn {
name: f.name.clone(),
module: mod_name.clone(),
};
if let Some(prior) = method_origins.get(&f.name) {
// Only fire on class-fn collisions here. fn-fn
// collisions (two `Def::Fn` with the same name)
// are `CheckError::DuplicateDef`'s job in
// `ailang-check`; firing here with `kind:
// "class-fn"` would misreport.
if matches!(prior, Origin::Class { .. }) {
return Err(WorkspaceLoadError::MethodNameCollision {
method: f.name.clone(),
kind: "class-fn",
first_origin: prior.format(),
second_origin: origin.format(),
});
}
// prior is a fn: skip; do not overwrite.
} else {
method_origins.insert(f.name.clone(), origin);
}
}
_ => {}
}
}
}
// Pass 2: register each instance, with coherence / uniqueness /
// method-completeness checks.
let mut entries: BTreeMap<(String, String), RegistryEntry> = BTreeMap::new();
for (mod_name, m) in modules {
for def in &m.defs {
if let Def::Instance(inst) = def {
let type_repr = type_head_name(&inst.type_);
// Coherence (orphan-freedom): instance's module must
// equal the class's module or the type's module. A
// class declared inside the same module as the
// instance always satisfies the first leg; a
// user-defined type declared in the instance's module
// satisfies the second. Primitives have no
// user-defined module — instances on primitives
// therefore must live in the class's module.
let class_mod = class_def_module
.get(&inst.class)
.cloned()
.unwrap_or_else(|| "<unknown-class>".into());
let type_mod = type_def_module
.get(&type_repr)
.cloned()
.unwrap_or_else(|| "<primitive-or-unknown>".into());
let coherent = mod_name == &class_mod || mod_name == &type_mod;
if !coherent {
return Err(WorkspaceLoadError::OrphanInstance {
class: inst.class.clone(),
type_repr,
defining_module: mod_name.clone(),
class_module: class_mod,
type_module: type_mod,
});
}
// Uniqueness: a `(class, type-hash)` key must appear
// at most once across the whole workspace.
let type_hash = canonical::type_hash(&inst.type_);
let key = (inst.class.clone(), type_hash);
if let Some(prior) = entries.get(&key) {
return Err(WorkspaceLoadError::DuplicateInstance {
class: inst.class.clone(),
type_repr,
first_module: prior.defining_module.clone(),
second_module: mod_name.clone(),
});
}
// Method completeness: every non-default method of
// the class must have a body in this instance.
// Defaults may be inherited (no body required).
// Missing class declaration is deferred to 22b.2's
// typecheck arms — for 22b.1 we skip the
// completeness check rather than firing a separate
// diagnostic.
if let Some(class_def) = class_by_name.get(&inst.class) {
let provided: BTreeSet<&str> =
inst.methods.iter().map(|m| m.name.as_str()).collect();
for class_method in &class_def.methods {
if class_method.default.is_none()
&& !provided.contains(class_method.name.as_str())
{
return Err(WorkspaceLoadError::MissingMethod {
class: inst.class.clone(),
type_repr,
method: class_method.name.clone(),
});
}
}
// Symmetric to MissingMethod: an instance must
// not specify a body for a method name the class
// never declared. Decision 11 forbids ad-hoc
// additions to a class's method set at the
// instance site.
let declared: BTreeSet<&str> =
class_def.methods.iter().map(|m| m.name.as_str()).collect();
for inst_method in &inst.methods {
if !declared.contains(inst_method.name.as_str()) {
return Err(WorkspaceLoadError::OverridingNonExistentMethod {
class: inst.class.clone(),
type_repr: type_repr.clone(),
method: inst_method.name.clone(),
});
}
}
}
entries.insert(
key,
RegistryEntry {
instance: inst.clone(),
defining_module: mod_name.clone(),
},
);
}
}
}
// Iter 22b.2: superclass-instance completeness. For every entry,
// walk the class's superclass chain and require an entry for each
// step at the same type-hash.
for (key, entry) in entries.iter() {
let (class_name, type_hash) = key;
let type_repr = type_head_name(&entry.instance.type_);
// Iter 22b.2 leaves superclass-cycle detection to a future arm;
// here we just terminate the walk.
let mut visited: BTreeSet<&str> = BTreeSet::new();
let mut current = class_by_name.get(class_name.as_str()).copied();
while let Some(c) = current {
if !visited.insert(c.name.as_str()) {
break;
}
if let Some(sc) = &c.superclass {
let sc_key = (sc.class.clone(), type_hash.clone());
if !entries.contains_key(&sc_key) {
return Err(WorkspaceLoadError::MissingSuperclassInstance {
class: class_name.clone(),
superclass: sc.class.clone(),
type_repr: type_repr.clone(),
});
}
current = class_by_name.get(sc.class.as_str()).copied();
} else {
break;
}
}
}
Ok(Registry { entries })
}
/// Iter 22b.2: class-schema validation. Runs before `build_registry`.
/// Three diagnostics fire from here: `kind-mismatch`,
/// `invalid-superclass-param`, `constraint-references-unbound-type-var`.
fn validate_classdefs(
modules: &BTreeMap<String, Module>,
) -> Result<(), WorkspaceLoadError> {
for (mod_name, m) in modules {
for def in &m.defs {
if let Def::Class(c) = def {
for method in &c.methods {
walk_kind_mismatch(&method.ty, &c.param)
.map_err(|()| WorkspaceLoadError::KindMismatch {
class: c.name.clone(),
param: c.param.clone(),
method: method.name.clone(),
defining_module: mod_name.clone(),
})?;
}
if let Some(sc) = &c.superclass {
if sc.type_ != c.param {
return Err(WorkspaceLoadError::InvalidSuperclassParam {
class: c.name.clone(),
superclass: sc.class.clone(),
expected_param: c.param.clone(),
got_type: sc.type_.clone(),
});
}
}
for method in &c.methods {
if let Type::Forall { vars, constraints, .. } = &method.ty {
let mut bound: BTreeSet<&str> =
vars.iter().map(String::as_str).collect();
bound.insert(c.param.as_str());
for constr in constraints {
if let Type::Var { name } = &constr.type_ {
if !bound.contains(name.as_str()) {
return Err(WorkspaceLoadError::UnboundConstraintTypeVar {
class: c.name.clone(),
method: method.name.clone(),
constraint_class: constr.class.clone(),
var: name.clone(),
});
}
}
}
}
}
}
}
}
Ok(())
}
/// Walks a `Type` looking for any `Type::Con { name == param, args
/// non-empty }`. The class param is kind `*`; appearing as a
/// constructor with arguments is a kind-mismatch.
fn walk_kind_mismatch(t: &Type, param: &str) -> Result<(), ()> {
match t {
Type::Con { name, args } => {
if name == param && !args.is_empty() {
return Err(());
}
for a in args {
walk_kind_mismatch(a, param)?;
}
Ok(())
}
Type::Fn { params, ret, .. } => {
for p in params {
walk_kind_mismatch(p, param)?;
}
walk_kind_mismatch(ret, param)
}
Type::Forall { body, .. } => walk_kind_mismatch(body, param),
Type::Var { .. } => Ok(()),
}
}
/// Iter 22b.1: extract the head-constructor name of a type, for the
/// "where is this type defined" lookup and for diagnostic-message
/// rendering.
///
/// For `Type::Con { name, .. }` (the only legal head shape for a
/// non-orphan instance) returns `name`. Other variants (`Var`,
/// `Forall`, `Fn`) are not legal as instance heads — Decision 11
/// requires a concrete type expression at the instance head — so we
/// emit a stable fallback string. The fallback prevents diagnostic
/// rendering from panicking on a malformed fixture; the "real"
/// rejection of non-concrete instance heads will arrive as a
/// schema-validation diagnostic in 22b.2.
fn type_head_name(t: &Type) -> String {
match t {
Type::Con { name, .. } => name.clone(),
Type::Var { name } => format!("<var:{name}>"),
Type::Forall { .. } => "<forall>".into(),
Type::Fn { .. } => "<fn>".into(),
}
}
fn visit(
module: Module,
root_dir: &Path,
modules: &mut BTreeMap<String, Module>,
visiting: &mut Vec<String>,
visiting_set: &mut HashSet<String>,
) -> Result<(), WorkspaceLoadError> {
let name = module.name.clone();
// Already fully loaded? Then do nothing. Hash consistency is checked
// on re-encounter via imports (see below in the loop).
if modules.contains_key(&name) {
return Ok(());
}
// Cycle: same name currently on the DFS stack.
if visiting_set.contains(&name) {
let mut path = visiting.clone();
path.push(name);
return Err(WorkspaceLoadError::Cycle { path });
}
visiting.push(name.clone());
visiting_set.insert(name.clone());
// Process imports recursively.
let imports = module.imports.clone();
for imp in &imports {
let imp_path = root_dir.join(format!("{}.ail.json", imp.module));
if let Some(existing) = modules.get(&imp.module) {
// Already fully loaded — check hash consistency, in case the
// file on disk has changed.
let on_disk = match load_one(&imp_path) {
Ok(m) => m,
Err(WorkspaceLoadError::Io { .. }) => continue,
Err(e) => return Err(e),
};
if module_hash(existing) != module_hash(&on_disk) {
return Err(WorkspaceLoadError::ModuleHashMismatch {
name: imp.module.clone(),
});
}
continue;
}
if visiting_set.contains(&imp.module) {
let mut path = visiting.clone();
path.push(imp.module.clone());
return Err(WorkspaceLoadError::Cycle { path });
}
if !imp_path.exists() {
return Err(WorkspaceLoadError::ModuleNotFound {
name: imp.module.clone(),
expected_path: imp_path,
});
}
let imported = load_one(&imp_path)?;
if imported.name != imp.module {
return Err(WorkspaceLoadError::ModuleNameMismatch {
name_in_file: imported.name,
name_from_path: imp.module.clone(),
});
}
visit(imported, root_dir, modules, visiting, visiting_set)?;
}
visiting.pop();
visiting_set.remove(&name);
modules.insert(name, module);
Ok(())
}
fn load_one(path: &Path) -> Result<Module, WorkspaceLoadError> {
match load_module(path) {
Ok(m) => Ok(m),
Err(CoreError::Io(e)) => Err(WorkspaceLoadError::Io {
path: path.to_path_buf(),
source: e,
}),
Err(e) => Err(WorkspaceLoadError::Schema {
path: path.to_path_buf(),
source: e,
}),
}
}
fn module_name_from_path(p: &Path) -> String {
let file = p.file_name().and_then(|s| s.to_str()).unwrap_or("");
// Convention: `<name>.ail.json`.
if let Some(stripped) = file.strip_suffix(".ail.json") {
return stripped.to_string();
}
// Fallback: strip only the last extension.
Path::new(file)
.file_stem()
.and_then(|s| s.to_str())
.unwrap_or(file)
.to_string()
}
#[cfg(test)]
mod tests {
use super::*;
use std::fs;
fn write_module(dir: &Path, name: &str, imports: &[&str]) -> PathBuf {
let imports_json: Vec<serde_json::Value> = imports
.iter()
.map(|m| serde_json::json!({ "module": m }))
.collect();
let module = serde_json::json!({
"schema": crate::SCHEMA,
"name": name,
"imports": imports_json,
"defs": [],
});
let path = dir.join(format!("{name}.ail.json"));
fs::write(&path, serde_json::to_vec_pretty(&module).unwrap()).unwrap();
path
}
fn tmp_dir(tag: &str) -> PathBuf {
let d = std::env::temp_dir().join(format!(
"ailang_workspace_test_{tag}_{}",
std::process::id()
));
let _ = fs::remove_dir_all(&d);
fs::create_dir_all(&d).unwrap();
d
}
#[test]
fn loads_example_workspace_happy_path() {
// Uses the canonical example files under `examples/`. This
// test documents that the loader relies on the committed
// workspace example.
let manifest_dir = env!("CARGO_MANIFEST_DIR");
let workspace_root =
Path::new(manifest_dir).parent().unwrap().parent().unwrap();
let entry = workspace_root.join("examples").join("ws_main.ail.json");
let ws = load_workspace(&entry).expect("load workspace");
assert_eq!(ws.entry, "ws_main");
assert!(ws.modules.contains_key("ws_main"));
assert!(ws.modules.contains_key("ws_lib"));
assert_eq!(ws.modules.len(), 2);
}
#[test]
fn detects_import_cycle() {
let dir = tmp_dir("cycle");
write_module(&dir, "a", &["b"]);
write_module(&dir, "b", &["a"]);
let entry = dir.join("a.ail.json");
let err = load_workspace(&entry).expect_err("must error on cycle");
match err {
WorkspaceLoadError::Cycle { path } => {
assert!(path.contains(&"a".to_string()));
assert!(path.contains(&"b".to_string()));
}
other => panic!("expected Cycle, got {other:?}"),
}
}
#[test]
fn module_not_found_yields_structured_error() {
let dir = tmp_dir("notfound");
write_module(&dir, "main", &["does_not_exist"]);
let entry = dir.join("main.ail.json");
let err = load_workspace(&entry).expect_err("must error on missing module");
match err {
WorkspaceLoadError::ModuleNotFound { name, expected_path } => {
assert_eq!(name, "does_not_exist");
assert!(expected_path.ends_with("does_not_exist.ail.json"));
}
other => panic!("expected ModuleNotFound, got {other:?}"),
}
}
/// Iter 22b.1: a workspace whose modules contain no
/// `Def::Instance` defs has an empty registry. This is the
/// happy-path baseline for the registry-build pass — every
/// pre-22b workspace falls into this case.
#[test]
fn iter22b1_workspace_with_no_classes_has_empty_registry() {
let manifest_dir = env!("CARGO_MANIFEST_DIR");
let workspace_root =
Path::new(manifest_dir).parent().unwrap().parent().unwrap();
let entry = workspace_root.join("examples").join("sum.ail.json");
let ws = load_workspace(&entry).expect("sum.ail.json loads");
assert!(
ws.registry.entries.is_empty(),
"pre-22b fixture has no class/instance defs, registry must be empty"
);
}
fn examples_dir() -> PathBuf {
let manifest_dir = env!("CARGO_MANIFEST_DIR");
Path::new(manifest_dir)
.parent()
.unwrap()
.parent()
.unwrap()
.join("examples")
}
/// Iter 22b.1: a coherent instance (in the class's module)
/// loads cleanly and produces one registry entry.
#[test]
fn iter22b1_instance_in_class_module_loads_clean() {
let entry = examples_dir().join("test_22b1_orphan_class.ail.json");
let ws = load_workspace(&entry).expect("coherent instance loads");
assert_eq!(ws.registry.entries.len(), 1);
let (key, entry) = ws.registry.entries.iter().next().unwrap();
assert_eq!(&key.0, "Show");
assert_eq!(entry.defining_module, "test_22b1_orphan_class");
assert_eq!(entry.instance.class, "Show");
}
/// Iter 22b.1: an instance declared in a module that is neither
/// the class's module nor the type's module fires `OrphanInstance`.
/// The fixture imports `test_22b1_orphan_third_classmod` (which
/// owns `class Show`) and the entry module declares `instance
/// Show Int` itself — but the entry is not the class's module
/// and `Int` is primitive, so neither leg of coherence is
/// satisfied.
#[test]
fn iter22b1_orphan_instance_fires_diagnostic() {
let entry = examples_dir().join("test_22b1_orphan_third.ail.json");
let err = load_workspace(&entry).expect_err("must fire orphan");
match err {
WorkspaceLoadError::OrphanInstance {
class,
type_repr,
defining_module,
..
} => {
assert_eq!(class, "Show");
assert_eq!(type_repr, "Int");
assert_eq!(defining_module, "test_22b1_orphan_third");
}
other => panic!("expected OrphanInstance, got {other:?}"),
}
}
/// Iter 22b.1: two instances of the same `(class, type)` pair
/// declared from coherent positions (one in the class's module,
/// one in the type's module) collide on the registry's
/// uniqueness check. Setup per the JOURNAL hint:
/// - module A defines `class Show` and declares
/// `instance Show MyInt` (legal, A is class's module).
/// - module B defines `type MyInt` and declares
/// `instance Show MyInt` (legal, B is type's module).
/// - entry module imports both A and B.
/// The build_registry pass sees both instances under the same
/// `(Show, hash-of-MyInt)` key and fires `DuplicateInstance`.
#[test]
fn iter22b1_duplicate_instance_fires_diagnostic() {
let entry = examples_dir().join("test_22b1_dup_entry.ail.json");
let err = load_workspace(&entry).expect_err("must fire duplicate");
match err {
WorkspaceLoadError::DuplicateInstance {
class,
type_repr,
first_module,
second_module,
} => {
assert_eq!(class, "Show");
assert_eq!(type_repr, "MyInt");
assert_ne!(first_module, second_module);
let modules: BTreeSet<&str> =
[first_module.as_str(), second_module.as_str()].iter().copied().collect();
assert!(modules.contains("test_22b1_dup_a"));
assert!(modules.contains("test_22b1_dup_b"));
}
other => panic!("expected DuplicateInstance, got {other:?}"),
}
}
/// Iter 22b.1: an instance that omits a required (non-default)
/// method of its class fires `MissingMethod`. The fixture's
/// `class Eq` declares `eq` and `ne` as both non-default; the
/// instance only specifies `ne`, leaving `eq` missing.
#[test]
fn iter22b1_missing_method_fires_diagnostic() {
let entry = examples_dir().join("test_22b1_missing_method.ail.json");
let err = load_workspace(&entry).expect_err("must fire missing-method");
match err {
WorkspaceLoadError::MissingMethod {
class,
type_repr,
method,
} => {
assert_eq!(class, "Eq");
assert_eq!(type_repr, "Int");
assert_eq!(method, "eq");
}
other => panic!("expected MissingMethod, got {other:?}"),
}
}
/// Iter 22b.2: a class whose parameter `f` appears in applied
/// position (`Type::Con { name == "f", args.len() > 0 }`) inside
/// a method signature must fire `KindMismatch`. Decision 11 axis
/// 5 forbids HKTs — class params are kind `*` only, never
/// constructors.
#[test]
fn class_param_in_applied_position_fires_kind_mismatch() {
let entry = std::path::PathBuf::from(
"../../examples/test_22b2_kind_mismatch.ail.json",
);
let err = load_workspace(&entry)
.expect_err("must fire kind-mismatch");
match err {
WorkspaceLoadError::KindMismatch { class, param, method, .. } => {
assert_eq!(class, "Functor");
assert_eq!(param, "f");
assert_eq!(method, "fmap");
}
other => panic!("expected KindMismatch, got {other:?}"),
}
}
/// Iter 22b.2: a class whose `superclass.type` differs from its
/// own `param` (e.g. `class Ord a extends Eq b`) must fire
/// `InvalidSuperclassParam`. Decision 11 axis 1 ("single
/// superclass, applied to the same param") makes the only legal
/// shape `extends Eq a` when the parent class has `param: "a"`.
#[test]
fn superclass_with_wrong_param_fires_invalid_superclass_param() {
let entry = std::path::PathBuf::from(
"../../examples/test_22b2_invalid_superclass_param.ail.json",
);
let err = load_workspace(&entry)
.expect_err("must fire invalid-superclass-param");
match err {
WorkspaceLoadError::InvalidSuperclassParam {
class, superclass, expected_param, got_type,
} => {
assert_eq!(class, "Ord");
assert_eq!(superclass, "Eq");
assert_eq!(expected_param, "a");
assert_eq!(got_type, "b");
}
other => panic!("expected InvalidSuperclassParam, got {other:?}"),
}
}
/// Iter 22b.2: an instance that specifies a body for a method
/// name the class never declared must fire
/// `OverridingNonExistentMethod`. Symmetric counterpart to
/// `MissingMethod`: the latter fires when the class declares a
/// non-default method that the instance omits; this one fires
/// when the instance provides a body the class did not ask for.
/// Decision 11 forbids ad-hoc additions to a class's method set
/// at the instance site.
#[test]
fn instance_overriding_nonexistent_method_fires() {
let entry = std::path::PathBuf::from(
"../../examples/test_22b2_overriding_nonexistent.ail.json",
);
let err = load_workspace(&entry)
.expect_err("must fire overriding-non-existent-method");
match err {
WorkspaceLoadError::OverridingNonExistentMethod {
class, type_repr, method,
} => {
assert_eq!(class, "Eq");
assert_eq!(type_repr, "Int");
assert_eq!(method, "ne");
}
other => panic!("expected OverridingNonExistentMethod, got {other:?}"),
}
}
/// Iter 22b.2: a class method's `Type::Forall` whose `constraints`
/// reference a type variable that is neither bound by `Forall.vars`
/// nor equal to the class's `param` must fire
/// `UnboundConstraintTypeVar`. The fixture's `class Foo a` declares
/// method `foo` with `forall a. (Bar z) => a -> Unit`; `z` is
/// bound nowhere, so the constraint is unsatisfiable by
/// construction.
#[test]
fn constraint_with_unbound_var_fires_unbound_constraint_type_var() {
let entry = std::path::PathBuf::from(
"../../examples/test_22b2_unbound_constraint_var.ail.json",
);
let err = load_workspace(&entry)
.expect_err("must fire constraint-references-unbound-type-var");
match err {
WorkspaceLoadError::UnboundConstraintTypeVar {
class, method, var, ..
} => {
assert_eq!(class, "Foo");
assert_eq!(method, "foo");
assert_eq!(var, "z");
}
other => panic!("expected UnboundConstraintTypeVar, got {other:?}"),
}
}
/// Iter 22b.2: two classes that declare a method with the same
/// name must fire `MethodNameCollision` with `kind == "class-class"`.
/// Decision 11 keeps method names workspace-unique so that bare
/// method-name resolution (`foo x` rather than `A.foo x`) is
/// unambiguous; if two classes both export `foo`, the registry has
/// no way to choose between them at a use site.
#[test]
fn class_class_method_name_collision_fires() {
let entry = examples_dir()
.join("test_22b2_method_name_collision_class_class.ail.json");
let err = load_workspace(&entry)
.expect_err("must fire method-name-collision");
match err {
WorkspaceLoadError::MethodNameCollision {
method,
kind,
first_origin,
second_origin,
} => {
assert_eq!(method, "foo");
assert_eq!(kind, "class-class");
assert!(
first_origin.starts_with("class A"),
"first_origin = {first_origin:?}",
);
assert!(
second_origin.starts_with("class B"),
"second_origin = {second_origin:?}",
);
}
other => panic!("expected MethodNameCollision, got {other:?}"),
}
}
/// Iter 22b.2: a class-method name that collides with a top-level
/// `fn` of the same name must fire `MethodNameCollision` with
/// `kind == "class-fn"`. Same rationale as the class-class case:
/// bare-name resolution must be unambiguous, and a class method
/// shadowing (or being shadowed by) a free function silently is
/// the worst possible failure mode.
#[test]
fn class_fn_method_name_collision_fires() {
let entry = examples_dir()
.join("test_22b2_method_name_collision_class_fn.ail.json");
let err = load_workspace(&entry)
.expect_err("must fire method-name-collision");
match err {
WorkspaceLoadError::MethodNameCollision {
method,
kind,
first_origin,
second_origin,
} => {
assert_eq!(method, "greet");
assert_eq!(kind, "class-fn");
assert!(
first_origin.starts_with("class Greet"),
"first_origin = {first_origin:?}",
);
assert!(
second_origin.starts_with("fn greet"),
"second_origin = {second_origin:?}",
);
}
other => panic!("expected MethodNameCollision, got {other:?}"),
}
}
/// Iter 22b.2: an instance `C T` whose class `C` declares a
/// superclass `S` requires that `instance S T` also exist in the
/// workspace. The fixture declares `class Eq a`, `class Ord a
/// extends Eq a`, and `instance Ord Int` — but no `instance Eq
/// Int` — so registry build must fire
/// `MissingSuperclassInstance`. Decision 11 single-superclass
/// model requires `instance S T` whenever `instance C T` exists.
#[test]
fn instance_without_superclass_instance_fires() {
let entry = examples_dir().join("test_22b2_missing_superclass_instance.ail.json");
let err = load_workspace(&entry)
.expect_err("must fire missing-superclass-instance");
match err {
WorkspaceLoadError::MissingSuperclassInstance {
class, superclass, type_repr,
} => {
assert_eq!(class, "Ord");
assert_eq!(superclass, "Eq");
assert_eq!(type_repr, "Int");
}
other => panic!("expected MissingSuperclassInstance, got {other:?}"),
}
}
}