From 8264df65c21b5ad508c5faf96c4a1f9d732449cc Mon Sep 17 00:00:00 2001
From: Nadrieril
Date: Mon, 17 Feb 2020 17:50:22 +0000
Subject: Move hir and resolve into a module

---
 dhall/src/semantics/resolve/env.rs | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 dhall/src/semantics/resolve/env.rs

(limited to 'dhall/src/semantics/resolve/env.rs')

diff --git a/dhall/src/semantics/resolve/env.rs b/dhall/src/semantics/resolve/env.rs
new file mode 100644
index 0000000..e69de29
-- 
cgit v1.2.3


From 8da4445e6d06cf79d43112042b69c798f86884f3 Mon Sep 17 00:00:00 2001
From: Nadrieril
Date: Mon, 17 Feb 2020 17:58:03 +0000
Subject: Extract resolve-relevant envs together

---
 dhall/src/semantics/resolve/env.rs | 104 +++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)

(limited to 'dhall/src/semantics/resolve/env.rs')

diff --git a/dhall/src/semantics/resolve/env.rs b/dhall/src/semantics/resolve/env.rs
index e69de29..ff743d3 100644
--- a/dhall/src/semantics/resolve/env.rs
+++ b/dhall/src/semantics/resolve/env.rs
@@ -0,0 +1,104 @@
+use std::collections::HashMap;
+
+use crate::error::{Error, ImportError};
+use crate::semantics::{AlphaVar, Hir, Import, VarEnv};
+use crate::syntax::{Label, V};
+
+/// Environment for resolving names.
+#[derive(Debug, Clone)]
+pub(crate) struct NameEnv {
+    names: Vec<Label>,
+}
+
+pub(crate) type ImportCache = HashMap<Import, Hir>;
+pub(crate) type ImportStack = Vec<Import>;
+
+/// Environment for resolving imports
+#[derive(Debug, Clone)]
+pub(crate) struct ImportEnv {
+    cache: ImportCache,
+    stack: ImportStack,
+}
+
+impl NameEnv {
+    pub fn new() -> Self {
+        NameEnv { names: Vec::new() }
+    }
+    pub fn as_varenv(&self) -> VarEnv {
+        VarEnv::from_size(self.names.len())
+    }
+
+    pub fn insert(&self, x: &Label) -> Self {
+        let mut env = self.clone();
+        env.insert_mut(x);
+        env
+    }
+    pub fn insert_mut(&mut self, x: &Label) {
+        self.names.push(x.clone())
+    }
+    pub fn remove_mut(&mut self) {
+        self.names.pop();
+    }
+
+    pub fn unlabel_var(&self, var: &V) -> Option<AlphaVar> {
+        let V(name, idx) = var;
+        let (idx, _) = self
+            .names
+            .iter()
+            .rev()
+            .enumerate()
+            .filter(|(_, n)| *n == name)
+            .nth(*idx)?;
+        Some(AlphaVar::new(idx))
+    }
+    pub fn label_var(&self, var: &AlphaVar) -> V {
+        let name = &self.names[self.names.len() - 1 - var.idx()];
+        let idx = self
+            .names
+            .iter()
+            .rev()
+            .take(var.idx())
+            .filter(|n| *n == name)
+            .count();
+        V(name.clone(), idx)
+    }
+}
+
+impl ImportEnv {
+    pub fn new() -> Self {
+        ImportEnv {
+            cache: HashMap::new(),
+            stack: Vec::new(),
+        }
+    }
+
+    pub fn handle_import(
+        &mut self,
+        import: Import,
+        mut do_resolve: impl FnMut(&mut Self, &Import) -> Result<Hir, Error>,
+    ) -> Result<Hir, Error> {
+        if self.stack.contains(&import) {
+            return Err(
+                ImportError::ImportCycle(self.stack.clone(), import).into()
+            );
+        }
+        Ok(match self.cache.get(&import) {
+            Some(expr) => expr.clone(),
+            None => {
+                // Push the current import on the stack
+                self.stack.push(import.clone());
+
+                // Resolve the import recursively
+                let expr = do_resolve(self, &import)?;
+
+                // Remove import from the stack.
+                self.stack.pop();
+
+                // Add the import to the cache
+                self.cache.insert(import, expr.clone());
+
+                expr
+            }
+        })
+    }
+}
-- 
cgit v1.2.3


From 7cbfc1a0d32766a383d1f48902502adaa2234d2f Mon Sep 17 00:00:00 2001
From: Nadrieril
Date: Tue, 18 Feb 2020 19:12:31 +0000
Subject: Avoid re-typechecking after import

---
 dhall/src/semantics/resolve/env.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'dhall/src/semantics/resolve/env.rs')

diff --git a/dhall/src/semantics/resolve/env.rs b/dhall/src/semantics/resolve/env.rs
index ff743d3..43676cc 100644
--- a/dhall/src/semantics/resolve/env.rs
+++ b/dhall/src/semantics/resolve/env.rs
@@ -1,7 +1,7 @@
 use std::collections::HashMap;
 
 use crate::error::{Error, ImportError};
-use crate::semantics::{AlphaVar, Hir, Import, VarEnv};
+use crate::semantics::{AlphaVar, Import, TypedHir, VarEnv};
 use crate::syntax::{Label, V};
 
 /// Environment for resolving names.
@@ -10,7 +10,7 @@ pub(crate) struct NameEnv {
     names: Vec<Label>,
 }
 
-pub(crate) type ImportCache = HashMap<Import, Hir>;
+pub(crate) type ImportCache = HashMap<Import, TypedHir>;
 pub(crate) type ImportStack = Vec<Import>;
 
 /// Environment for resolving imports
@@ -75,8 +75,8 @@ impl ImportEnv {
     pub fn handle_import(
         &mut self,
         import: Import,
-        mut do_resolve: impl FnMut(&mut Self, &Import) -> Result<Hir, Error>,
-    ) -> Result<Hir, Error> {
+        mut do_resolve: impl FnMut(&mut Self, &Import) -> Result<TypedHir, Error>,
+    ) -> Result<TypedHir, Error> {
         if self.stack.contains(&import) {
             return Err(
                 ImportError::ImportCycle(self.stack.clone(), import).into()
-- 
cgit v1.2.3