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authorNadrieril2020-11-01 14:53:38 +0000
committerNadrieril2020-11-01 14:53:38 +0000
commit8a2de7537986b1d60b9e8ce3bc4c08e9ec6c489a (patch)
tree2f5c672f9ff03c5449247068fde9d9152138c5c4 /dhall/src/semantics
parent48037367933085ca9c1c67c8c59f311e2b21be6d (diff)
Untangle ImportEnv::handle_import
Diffstat (limited to 'dhall/src/semantics')
-rw-r--r--dhall/src/semantics/resolve/env.rs43
-rw-r--r--dhall/src/semantics/resolve/resolve.rs23
2 files changed, 37 insertions, 29 deletions
diff --git a/dhall/src/semantics/resolve/env.rs b/dhall/src/semantics/resolve/env.rs
index 6346a6d..25d2277 100644
--- a/dhall/src/semantics/resolve/env.rs
+++ b/dhall/src/semantics/resolve/env.rs
@@ -69,9 +69,20 @@ impl ImportEnv {
ImportEnv::default()
}
- pub fn handle_import(
+ pub fn get_from_cache<'a>(
+ &'a self,
+ location: &ImportLocation,
+ ) -> Option<&'a TypedHir> {
+ self.cache.get(location)
+ }
+
+ pub fn set_cache(&mut self, location: ImportLocation, expr: TypedHir) {
+ self.cache.insert(location, expr);
+ }
+
+ pub fn with_cycle_detection(
&mut self,
- mut location: ImportLocation,
+ location: ImportLocation,
do_resolve: impl FnOnce(&mut Self) -> Result<TypedHir, Error>,
) -> Result<TypedHir, Error> {
if self.stack.contains(&location) {
@@ -79,25 +90,13 @@ impl ImportEnv {
ImportError::ImportCycle(self.stack.clone(), location).into()
);
}
- Ok(match self.cache.get(&location) {
- Some(expr) => expr.clone(),
- None => {
- let expr = {
- // Push the current location on the stack
- self.stack.push(location);
- // Resolve the import recursively
- // WARNING: do not propagate errors here or the stack will get messed up.
- let result = do_resolve(self);
- // Remove location from the stack.
- location = self.stack.pop().unwrap();
- result
- }?;
-
- // Add the resolved import to the cache
- self.cache.insert(location, expr.clone());
-
- expr
- }
- })
+ // Push the current location on the stack
+ self.stack.push(location);
+ // Resolve the import recursively
+ // WARNING: do not propagate errors here or the stack will get messed up.
+ let result = do_resolve(self);
+ // Remove location from the stack.
+ self.stack.pop().unwrap();
+ result
}
}
diff --git a/dhall/src/semantics/resolve/resolve.rs b/dhall/src/semantics/resolve/resolve.rs
index 2b401dc..f6d664e 100644
--- a/dhall/src/semantics/resolve/resolve.rs
+++ b/dhall/src/semantics/resolve/resolve.rs
@@ -224,12 +224,10 @@ fn resolve_one_import(
env: &mut ImportEnv,
cache: &Cache,
import: &Import,
- location: &ImportLocation,
+ location: ImportLocation,
span: Span,
) -> Result<TypedHir, Error> {
- let do_sanity_check = import.mode != ImportMode::Location;
- let location = location.chain(&import.location, do_sanity_check)?;
- env.handle_import(location.clone(), |env| match import.mode {
+ match import.mode {
ImportMode::Code => {
let (hir, ty) = cache.caching_import(
import,
@@ -278,7 +276,7 @@ fn resolve_one_import(
let ty = hir.typecheck_noenv()?.ty().clone();
Ok((hir, ty))
}
- })
+ }
}
/// Desugar a `with` expression.
@@ -396,12 +394,23 @@ fn resolve_with_env(
cache: &Cache,
parsed: Parsed,
) -> Result<Resolved, Error> {
- let Parsed(expr, location) = parsed;
+ let Parsed(expr, base_location) = parsed;
let resolved = traverse_resolve_expr(
&mut NameEnv::new(),
&expr,
&mut |import, span| {
- resolve_one_import(env, cache, &import, &location, span)
+ let do_sanity_check = import.mode != ImportMode::Location;
+ let location =
+ base_location.chain(&import.location, do_sanity_check)?;
+ if let Some(expr) = env.get_from_cache(&location) {
+ return Ok(expr.clone());
+ }
+ let expr = env.with_cycle_detection(location.clone(), |env| {
+ resolve_one_import(env, cache, &import, location.clone(), span)
+ })?;
+ // Add the resolved import to the cache
+ env.set_cache(location, expr.clone());
+ Ok(expr)
},
)?;
Ok(Resolved(resolved))