use super::Expander;
use super::context::DefinitionContext;
use super::rest_of_body::RestOfBody;
use crate::core::{
Binder, BindingId, BindingKind, BodyItem, Declaration, Expr, ExprKind, Leaf, ModuleId,
Namespace,
};
use crate::diagnostic::Diagnostic;
use crate::reader::{Form, Symbol};
use crate::scope::{Phase, Scope, ScopeKind};
pub(super) struct DeclaredName {
name: Form,
declaration: Declaration,
introduction: Scope,
}
impl DeclaredName {
pub(super) fn new(name: Form, declaration: Declaration, introduction: Scope) -> Self {
Self {
name,
declaration,
introduction,
}
}
fn binder(&self) -> Form {
let mut binder = self.name.clone();
binder.flip_scope(self.introduction);
binder
}
}
impl Expander<'_> {
pub(super) fn apply_definer(
&mut self,
definer: BindingId,
call: Form,
context: &mut DefinitionContext,
) -> Result<Form, Diagnostic> {
self.declared_definitions.clear();
let expansion = self.apply_macro(definer, call, Some(context));
if expansion.is_err() {
self.bind_failed_names(context);
}
expansion
}
pub(super) fn failed_macro_use(&self, form: &Form) -> Option<Expr> {
if !self.tables.globals.has_failed_definitions() {
return None;
}
let head = form.as_list()?.first()?.as_symbol()?;
let binding = self.try_resolve(head, Namespace::Value)?;
self.tables
.globals
.is_failed_macro_definition(binding)
.then(|| Expr::new(ExprKind::Leaf(Leaf::Var(binding)), form.span()))
}
pub(super) fn bind_failed_call_names(&mut self, call: &Form, context: &DefinitionContext) {
let module = self
.current_module
.expect("a top-level call expands inside a module");
let arguments = call.as_list().into_iter().flatten().skip(1);
for argument in arguments {
if self.is_unbound_name(argument) {
self.bind_failed_name(argument, Declaration::Value, module, context);
}
}
}
fn is_unbound_name(&self, form: &Form) -> bool {
form.as_symbol()
.is_some_and(|symbol| self.try_resolve(symbol, Namespace::Value).is_none())
}
pub(super) fn bind_over_failed(
&mut self,
symbol: &Symbol,
namespace: Namespace,
binding: BindingId,
phase: Phase,
) -> Result<(), BindingId> {
match self.tables.table.bind(symbol, namespace, binding, phase) {
Err(existing) if self.tables.globals.is_failed_definition(existing) => {
self.forget_failed(symbol, namespace, existing);
self.tables.table.bind(symbol, namespace, binding, phase)
}
bound => bound,
}
}
fn forget_failed(&mut self, symbol: &Symbol, namespace: Namespace, failed: BindingId) {
self.tables.table.unbind(symbol, namespace, failed);
self.tables.globals.forget_failed_definition(failed);
}
pub(super) fn bind_failed_body_names(
&mut self,
failure: &Expr,
rest_of_body: &mut RestOfBody,
context: &DefinitionContext,
) -> Vec<BodyItem> {
let names = self.declared_value_names();
if names.is_empty() {
return vec![BodyItem::Expr(failure.clone())];
}
let scope = self.tables.scopes.fresh(ScopeKind::Local);
rest_of_body.add_scope(scope);
names
.into_iter()
.filter_map(|(name, declaration)| {
self.bind_failed_body_name(&Self::scoped(&name, scope), declaration, context)
})
.map(|binder| BodyItem::Let(binder, failure.clone()))
.collect()
}
fn bind_failed_body_name(
&mut self,
name: &Form,
declaration: Declaration,
context: &DefinitionContext,
) -> Option<Binder> {
let binder = self.lower_binder(name, Some(context)).ok()?;
self.tables
.globals
.record_failed_definition(binder.binding, declaration);
self.failed_body_definitions.push(binder.binding);
Some(binder)
}
pub(super) fn forget_failed_body_definitions(&mut self, from: usize) {
for binding in self.failed_body_definitions.split_off(from) {
self.tables.globals.forget_failed_definition(binding);
}
}
fn declared_value_names(&self) -> Vec<(Form, Declaration)> {
self.declared_definitions
.iter()
.filter(|declared| declared.declaration.namespace() == Namespace::Value)
.map(|declared| (declared.binder(), declared.declaration))
.collect()
}
fn bind_failed_names(&mut self, context: &DefinitionContext) {
let module = self
.current_module
.expect("a top-level call expands inside a module");
let declared = std::mem::take(&mut self.declared_definitions);
for name in &declared {
self.bind_failed_name(&name.binder(), name.declaration, module, context);
}
self.declared_definitions = declared;
}
fn bind_failed_name(
&mut self,
name: &Form,
declaration: Declaration,
module: ModuleId,
context: &DefinitionContext,
) {
let namespace = declaration.namespace();
let kind = Self::failed_kind(namespace, module);
if let Ok(binding) = self.define_unrecorded_global(name, namespace, kind, context) {
self.tables
.globals
.record_failed_definition(binding, declaration);
}
}
fn failed_kind(namespace: Namespace, module: ModuleId) -> BindingKind {
match namespace {
Namespace::Value => BindingKind::Global(module),
Namespace::Type => BindingKind::Struct(module),
}
}
}
#[cfg(test)]
mod tests {
use std::path::PathBuf;
use super::*;
use crate::core::ModulePath;
use crate::modules::ModuleSources;
use crate::source::SourceMap;
struct ModulesFixture {
sources: SourceMap,
}
impl ModulesFixture {
fn new() -> Self {
Self {
sources: SourceMap::default(),
}
}
fn expand(&mut self, modules: &[(&str, &str)]) -> FailureRecord {
let ids: Vec<_> = modules
.iter()
.map(|(path, text)| (*path, self.sources.add(*path, *text)))
.collect();
let mut expander = Expander::new(
&mut self.sources,
ModuleSources::new(PathBuf::new(), PathBuf::new()),
);
for (path, id) in ids {
expander.load_source_module(ModulePath::new(path), &[id]);
}
FailureRecord {
declared: expander
.declared_definitions
.iter()
.map(|declared| declared.name.to_string())
.collect(),
has_failed_definitions: expander.tables.globals.has_failed_definitions(),
}
}
}
struct FailureRecord {
declared: Vec<String>,
has_failed_definitions: bool,
}
#[test]
fn a_failing_top_level_call_holds_only_its_own_declarations() {
let record = ModulesFixture::new().expand(&[
("body", "(defn outer () 1 (defrule inner ((x) x)))"),
("top", "(defn area \"doc\" (w) w)"),
]);
assert_eq!(record.declared, ["area"]);
}
#[test]
fn a_failed_body_level_definer_is_forgotten_when_its_body_ends() {
let record = ModulesFixture::new()
.expand(&[("body", "(defn outer () (defmacro dsl \"doc\" (x) x) 1)")]);
assert!(!record.has_failed_definitions);
}
}