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authorNadrieril2020-12-08 18:47:41 +0000
committerGitHub2020-12-08 18:47:41 +0000
commit109dcf894e759bce1c28f9ae94f3fdaa6e08feb5 (patch)
tree9ce374d02ea15966c7bb2dfb39d5d81720a63687 /dhall/src/semantics/resolve
parent35ed301e8de5a2b1102e370e638564d3c3d204a8 (diff)
parentd0a61179addf838d33e7e7a4c6a13f06e871e9c5 (diff)
Merge pull request #204 from Nadrieril/source-id
Diffstat (limited to 'dhall/src/semantics/resolve')
-rw-r--r--dhall/src/semantics/resolve/cache.rs35
-rw-r--r--dhall/src/semantics/resolve/env.rs59
-rw-r--r--dhall/src/semantics/resolve/hir.rs87
-rw-r--r--dhall/src/semantics/resolve/resolve.rs332
4 files changed, 342 insertions, 171 deletions
diff --git a/dhall/src/semantics/resolve/cache.rs b/dhall/src/semantics/resolve/cache.rs
index b00a2d5..1fc8dd3 100644
--- a/dhall/src/semantics/resolve/cache.rs
+++ b/dhall/src/semantics/resolve/cache.rs
@@ -5,7 +5,7 @@ use std::path::{Path, PathBuf};
use crate::error::{CacheError, Error};
use crate::parse::parse_binary;
use crate::syntax::{binary, Hash};
-use crate::Typed;
+use crate::{Ctxt, Typed};
use std::ffi::OsStr;
use std::fs::File;
@@ -52,9 +52,13 @@ impl Cache {
self.cache_dir.join(filename_for_hash(hash))
}
- pub fn get(&self, hash: &Hash) -> Result<Typed, Error> {
+ pub fn get<'cx>(
+ &self,
+ cx: Ctxt<'cx>,
+ hash: &Hash,
+ ) -> Result<Typed<'cx>, Error> {
let path = self.entry_path(hash);
- let res = read_cache_file(&path, hash);
+ let res = read_cache_file(cx, &path, hash);
if res.is_err() && path.exists() {
// Delete cache file since it's invalid. We ignore the error.
let _ = std::fs::remove_file(&path);
@@ -62,14 +66,23 @@ impl Cache {
res
}
- pub fn insert(&self, hash: &Hash, expr: &Typed) -> Result<(), Error> {
+ pub fn insert<'cx>(
+ &self,
+ cx: Ctxt<'cx>,
+ hash: &Hash,
+ expr: &Typed<'cx>,
+ ) -> Result<(), Error> {
let path = self.entry_path(hash);
- write_cache_file(&path, expr)
+ write_cache_file(cx, &path, expr)
}
}
/// Read a file from the cache, also checking that its hash is valid.
-fn read_cache_file(path: &Path, hash: &Hash) -> Result<Typed, Error> {
+fn read_cache_file<'cx>(
+ cx: Ctxt<'cx>,
+ path: &Path,
+ hash: &Hash,
+) -> Result<Typed<'cx>, Error> {
let data = crate::utils::read_binary_file(path)?;
match hash {
@@ -81,12 +94,16 @@ fn read_cache_file(path: &Path, hash: &Hash) -> Result<Typed, Error> {
}
}
- Ok(parse_binary(&data)?.skip_resolve()?.typecheck()?)
+ Ok(parse_binary(&data)?.resolve(cx)?.typecheck(cx)?)
}
/// Write a file to the cache.
-fn write_cache_file(path: &Path, expr: &Typed) -> Result<(), Error> {
- let data = binary::encode(&expr.to_expr())?;
+fn write_cache_file<'cx>(
+ cx: Ctxt<'cx>,
+ path: &Path,
+ expr: &Typed<'cx>,
+) -> Result<(), Error> {
+ let data = binary::encode(&expr.to_expr(cx))?;
File::create(path)?.write_all(data.as_slice())?;
Ok(())
}
diff --git a/dhall/src/semantics/resolve/env.rs b/dhall/src/semantics/resolve/env.rs
index 29dd16b..bde99d1 100644
--- a/dhall/src/semantics/resolve/env.rs
+++ b/dhall/src/semantics/resolve/env.rs
@@ -1,9 +1,9 @@
use std::collections::HashMap;
use crate::error::{Error, ImportError};
-use crate::semantics::{AlphaVar, Cache, ImportLocation, VarEnv};
+use crate::semantics::{check_hash, AlphaVar, Cache, ImportLocation, VarEnv};
use crate::syntax::{Hash, Label, V};
-use crate::Typed;
+use crate::{Ctxt, ImportId, ImportResultId, Typed};
/// Environment for resolving names.
#[derive(Debug, Clone, Default)]
@@ -11,14 +11,13 @@ pub struct NameEnv {
names: Vec<Label>,
}
-pub type MemCache = HashMap<ImportLocation, Typed>;
pub type CyclesStack = Vec<ImportLocation>;
/// Environment for resolving imports
-#[derive(Debug)]
-pub struct ImportEnv {
- disk_cache: Option<Cache>, // Missing if it failed to initialize
- mem_cache: MemCache,
+pub struct ImportEnv<'cx> {
+ cx: Ctxt<'cx>,
+ disk_cache: Option<Cache>, // `None` if it failed to initialize
+ mem_cache: HashMap<ImportLocation, ImportResultId<'cx>>,
stack: CyclesStack,
}
@@ -66,43 +65,61 @@ impl NameEnv {
}
}
-impl ImportEnv {
- pub fn new() -> Self {
+impl<'cx> ImportEnv<'cx> {
+ pub fn new(cx: Ctxt<'cx>) -> Self {
ImportEnv {
+ cx,
disk_cache: Cache::new().ok(),
mem_cache: Default::default(),
stack: Default::default(),
}
}
+ pub fn cx(&self) -> Ctxt<'cx> {
+ self.cx
+ }
+
pub fn get_from_mem_cache(
- &mut self,
+ &self,
location: &ImportLocation,
- ) -> Option<Typed> {
- Some(self.mem_cache.get(location)?.clone())
+ ) -> Option<ImportResultId<'cx>> {
+ Some(*self.mem_cache.get(location)?)
}
pub fn get_from_disk_cache(
- &mut self,
+ &self,
hash: &Option<Hash>,
- ) -> Option<Typed> {
+ ) -> Option<Typed<'cx>> {
let hash = hash.as_ref()?;
- let expr = self.disk_cache.as_ref()?.get(hash).ok()?;
+ let expr = self.disk_cache.as_ref()?.get(self.cx(), hash).ok()?;
Some(expr)
}
+ pub fn check_hash(
+ &self,
+ import: ImportId<'cx>,
+ result: ImportResultId<'cx>,
+ ) -> Result<(), Error> {
+ check_hash(self.cx(), import, result)
+ }
+
pub fn write_to_mem_cache(
&mut self,
location: ImportLocation,
- expr: Typed,
+ result: ImportResultId<'cx>,
) {
- self.mem_cache.insert(location, expr);
+ self.mem_cache.insert(location, result);
}
- pub fn write_to_disk_cache(&mut self, hash: &Option<Hash>, expr: &Typed) {
+ pub fn write_to_disk_cache(
+ &self,
+ hash: &Option<Hash>,
+ result: ImportResultId<'cx>,
+ ) {
if let Some(disk_cache) = self.disk_cache.as_ref() {
if let Some(hash) = hash {
- let _ = disk_cache.insert(hash, &expr);
+ let expr = &self.cx()[result];
+ let _ = disk_cache.insert(self.cx(), hash, expr);
}
}
}
@@ -110,8 +127,8 @@ impl ImportEnv {
pub fn with_cycle_detection(
&mut self,
location: ImportLocation,
- do_resolve: impl FnOnce(&mut Self) -> Result<Typed, Error>,
- ) -> Result<Typed, Error> {
+ do_resolve: impl FnOnce(&mut Self) -> Result<Typed<'cx>, Error>,
+ ) -> Result<Typed<'cx>, Error> {
if self.stack.contains(&location) {
return Err(
ImportError::ImportCycle(self.stack.clone(), location).into()
diff --git a/dhall/src/semantics/resolve/hir.rs b/dhall/src/semantics/resolve/hir.rs
index 8869915..8baad10 100644
--- a/dhall/src/semantics/resolve/hir.rs
+++ b/dhall/src/semantics/resolve/hir.rs
@@ -1,7 +1,7 @@
use crate::error::TypeError;
-use crate::semantics::{type_with, NameEnv, Nir, NzEnv, Tir, TyEnv, Type};
+use crate::semantics::{type_with, typecheck, NameEnv, Nir, NzEnv, Tir, TyEnv};
use crate::syntax::{Expr, ExprKind, Span, V};
-use crate::ToExprOptions;
+use crate::{Ctxt, ImportAlternativeId, ImportId, ToExprOptions};
/// Stores an alpha-normalized variable.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -10,19 +10,23 @@ pub struct AlphaVar {
}
#[derive(Debug, Clone, PartialEq, Eq)]
-pub enum HirKind {
+pub enum HirKind<'cx> {
/// A resolved variable (i.e. a DeBruijn index)
Var(AlphaVar),
- /// Result of resolving an import.
- Import(Hir, Type),
+ /// A variable that couldn't be resolved. Detected during resolution, but causes an error during typeck.
+ MissingVar(V),
+ /// An import. It must have been resolved after resolution.
+ Import(ImportId<'cx>),
+ /// An import alternative. It must have been decided after resolution.
+ ImportAlternative(ImportAlternativeId<'cx>, Hir<'cx>, Hir<'cx>),
// Forbidden ExprKind variants: Var, Import, Completion
- Expr(ExprKind<Hir>),
+ Expr(ExprKind<Hir<'cx>>),
}
// An expression with resolved variables and imports.
#[derive(Debug, Clone)]
-pub struct Hir {
- kind: Box<HirKind>,
+pub struct Hir<'cx> {
+ kind: Box<HirKind<'cx>>,
span: Span,
}
@@ -35,15 +39,15 @@ impl AlphaVar {
}
}
-impl Hir {
- pub fn new(kind: HirKind, span: Span) -> Self {
+impl<'cx> Hir<'cx> {
+ pub fn new(kind: HirKind<'cx>, span: Span) -> Self {
Hir {
kind: Box::new(kind),
span,
}
}
- pub fn kind(&self) -> &HirKind {
+ pub fn kind(&self) -> &HirKind<'cx> {
&*self.kind
}
pub fn span(&self) -> Span {
@@ -51,59 +55,78 @@ impl Hir {
}
/// Converts a closed Hir expr back to the corresponding AST expression.
- pub fn to_expr(&self, opts: ToExprOptions) -> Expr {
- hir_to_expr(self, opts, &mut NameEnv::new())
+ pub fn to_expr(&self, cx: Ctxt<'cx>, opts: ToExprOptions) -> Expr {
+ hir_to_expr(cx, self, opts, &mut NameEnv::new())
}
/// Converts a closed Hir expr back to the corresponding AST expression.
- pub fn to_expr_noopts(&self) -> Expr {
+ pub fn to_expr_noopts(&self, cx: Ctxt<'cx>) -> Expr {
let opts = ToExprOptions { alpha: false };
- self.to_expr(opts)
+ self.to_expr(cx, opts)
}
- pub fn to_expr_alpha(&self) -> Expr {
+ pub fn to_expr_alpha(&self, cx: Ctxt<'cx>) -> Expr {
let opts = ToExprOptions { alpha: true };
- self.to_expr(opts)
+ self.to_expr(cx, opts)
}
- pub fn to_expr_tyenv(&self, env: &TyEnv) -> Expr {
+ pub fn to_expr_tyenv(&self, env: &TyEnv<'cx>) -> Expr {
let opts = ToExprOptions { alpha: false };
+ let cx = env.cx();
let mut env = env.as_nameenv().clone();
- hir_to_expr(self, opts, &mut env)
+ hir_to_expr(cx, self, opts, &mut env)
}
/// Typecheck the Hir.
pub fn typecheck<'hir>(
&'hir self,
- env: &TyEnv,
- ) -> Result<Tir<'hir>, TypeError> {
+ env: &TyEnv<'cx>,
+ ) -> Result<Tir<'cx, 'hir>, TypeError> {
type_with(env, self, None)
}
- pub fn typecheck_noenv<'hir>(&'hir self) -> Result<Tir<'hir>, TypeError> {
- self.typecheck(&TyEnv::new())
+ pub fn typecheck_noenv<'hir>(
+ &'hir self,
+ cx: Ctxt<'cx>,
+ ) -> Result<Tir<'cx, 'hir>, TypeError> {
+ typecheck(cx, self)
}
/// Eval the Hir. It will actually get evaluated only as needed on demand.
- pub fn eval(&self, env: impl Into<NzEnv>) -> Nir {
+ pub fn eval(&self, env: impl Into<NzEnv<'cx>>) -> Nir<'cx> {
Nir::new_thunk(env.into(), self.clone())
}
/// Eval a closed Hir (i.e. without free variables). It will actually get evaluated only as
/// needed on demand.
- pub fn eval_closed_expr(&self) -> Nir {
- self.eval(NzEnv::new())
+ pub fn eval_closed_expr(&self, cx: Ctxt<'cx>) -> Nir<'cx> {
+ self.eval(NzEnv::new(cx))
}
}
-fn hir_to_expr(hir: &Hir, opts: ToExprOptions, env: &mut NameEnv) -> Expr {
+fn hir_to_expr<'cx>(
+ cx: Ctxt<'cx>,
+ hir: &Hir<'cx>,
+ opts: ToExprOptions,
+ env: &mut NameEnv,
+) -> Expr {
let kind = match hir.kind() {
HirKind::Var(v) if opts.alpha => ExprKind::Var(V("_".into(), v.idx())),
HirKind::Var(v) => ExprKind::Var(env.label_var(*v)),
- HirKind::Import(hir, _) => {
- return hir_to_expr(hir, opts, &mut NameEnv::new())
+ HirKind::MissingVar(v) => ExprKind::Var(v.clone()),
+ HirKind::Import(import) => {
+ let typed = cx[import].unwrap_result();
+ return hir_to_expr(cx, &typed.hir, opts, &mut NameEnv::new());
+ }
+ HirKind::ImportAlternative(alt, left, right) => {
+ let hir = if cx[alt].unwrap_selected() {
+ left
+ } else {
+ right
+ };
+ return hir_to_expr(cx, hir, opts, env);
}
HirKind::Expr(e) => {
let e = e.map_ref_maybe_binder(|l, hir| {
if let Some(l) = l {
env.insert_mut(l);
}
- let e = hir_to_expr(hir, opts, env);
+ let e = hir_to_expr(cx, hir, opts, env);
if l.is_some() {
env.remove_mut();
}
@@ -124,9 +147,9 @@ fn hir_to_expr(hir: &Hir, opts: ToExprOptions, env: &mut NameEnv) -> Expr {
Expr::new(kind, hir.span())
}
-impl std::cmp::PartialEq for Hir {
+impl<'cx> std::cmp::PartialEq for Hir<'cx> {
fn eq(&self, other: &Self) -> bool {
self.kind == other.kind
}
}
-impl std::cmp::Eq for Hir {}
+impl<'cx> std::cmp::Eq for Hir<'cx> {}
diff --git a/dhall/src/semantics/resolve/resolve.rs b/dhall/src/semantics/resolve/resolve.rs
index 16987de..116e1a5 100644
--- a/dhall/src/semantics/resolve/resolve.rs
+++ b/dhall/src/semantics/resolve/resolve.rs
@@ -15,7 +15,10 @@ use crate::syntax::{
Expr, ExprKind, FilePath, FilePrefix, Hash, ImportMode, ImportTarget, Span,
UnspannedExpr, URL,
};
-use crate::{Parsed, Resolved, Typed};
+use crate::{
+ Ctxt, ImportAlternativeId, ImportId, ImportResultId, Parsed, Resolved,
+ Typed,
+};
// TODO: evaluate import headers
pub type Import = syntax::Import<()>;
@@ -29,8 +32,10 @@ enum ImportLocationKind {
Remote(Url),
/// Environment variable
Env(String),
- /// Data without a location
+ /// Data without a location; chaining will start from current directory.
Missing,
+ /// Token to signal that thi sfile should contain no imports.
+ NoImport,
}
/// The location of some data.
@@ -101,6 +106,7 @@ impl ImportLocationKind {
url = url.join(&path.file_path.join("/"))?;
ImportLocationKind::Remote(url)
}
+ ImportLocationKind::NoImport => unreachable!(),
})
}
@@ -120,6 +126,7 @@ impl ImportLocationKind {
ImportLocationKind::Missing => {
return Err(ImportError::Missing.into())
}
+ ImportLocationKind::NoImport => unreachable!(),
})
}
@@ -134,6 +141,7 @@ impl ImportLocationKind {
ImportLocationKind::Missing => {
return Err(ImportError::Missing.into())
}
+ ImportLocationKind::NoImport => unreachable!(),
})
}
@@ -149,6 +157,7 @@ impl ImportLocationKind {
("Environment", Some(name.clone()))
}
ImportLocationKind::Missing => ("Missing", None),
+ ImportLocationKind::NoImport => unreachable!(),
};
let asloc_ty = make_aslocation_uniontype();
@@ -171,6 +180,12 @@ impl ImportLocation {
mode: ImportMode::Code,
}
}
+ pub fn dhall_code_without_imports() -> Self {
+ ImportLocation {
+ kind: ImportLocationKind::NoImport,
+ mode: ImportMode::Code,
+ }
+ }
pub fn local_dhall_code(path: PathBuf) -> Self {
ImportLocation {
kind: ImportLocationKind::Local(path),
@@ -191,6 +206,10 @@ impl ImportLocation {
fn chain(&self, import: &Import) -> Result<ImportLocation, Error> {
// Makes no sense to chain an import if the current file is not a dhall file.
assert!(matches!(self.mode, ImportMode::Code));
+ if matches!(self.kind, ImportLocationKind::NoImport) {
+ Err(ImportError::UnexpectedImport(import.clone()))?;
+ }
+
let kind = match &import.location {
ImportTarget::Local(prefix, path) => {
self.kind.chain_local(*prefix, path)?
@@ -227,30 +246,42 @@ impl ImportLocation {
}
/// Fetches the expression corresponding to this location.
- fn fetch(&self, env: &mut ImportEnv, span: Span) -> Result<Typed, Error> {
- let (hir, ty) = match self.mode {
+ fn fetch<'cx>(
+ &self,
+ env: &mut ImportEnv<'cx>,
+ span: Span,
+ ) -> Result<Typed<'cx>, Error> {
+ let cx = env.cx();
+ let typed = match self.mode {
ImportMode::Code => {
let parsed = self.kind.fetch_dhall()?;
- let typed = resolve_with_env(env, parsed)?.typecheck()?;
- let hir = typed.normalize().to_hir();
- (hir, typed.ty)
+ let typed = parsed.resolve_with_env(env)?.typecheck(cx)?;
+ Typed {
+ // TODO: manage to keep the Nir around. Will need fixing variables.
+ hir: typed.normalize(cx).to_hir(),
+ ty: typed.ty,
+ }
}
ImportMode::RawText => {
let text = self.kind.fetch_text()?;
- let hir = Hir::new(
- HirKind::Expr(ExprKind::TextLit(text.into())),
- span,
- );
- (hir, Type::from_builtin(Builtin::Text))
+ Typed {
+ hir: Hir::new(
+ HirKind::Expr(ExprKind::TextLit(text.into())),
+ span,
+ ),
+ ty: Type::from_builtin(cx, Builtin::Text),
+ }
}
ImportMode::Location => {
let expr = self.kind.to_location();
- let hir = skip_resolve_expr(&expr)?;
- let ty = hir.typecheck_noenv()?.ty().clone();
- (hir, ty)
+ Parsed::from_expr_without_imports(expr)
+ .resolve(cx)
+ .unwrap()
+ .typecheck(cx)
+ .unwrap()
}
};
- Ok(Typed { hir, ty })
+ Ok(typed)
}
}
@@ -282,15 +313,21 @@ fn make_aslocation_uniontype() -> Expr {
mkexpr(ExprKind::UnionType(union))
}
-fn check_hash(import: &Import, typed: &Typed, span: Span) -> Result<(), Error> {
+pub fn check_hash<'cx>(
+ cx: Ctxt<'cx>,
+ import: ImportId<'cx>,
+ result: ImportResultId<'cx>,
+) -> Result<(), Error> {
+ let import = &cx[import];
if let (ImportMode::Code, Some(Hash::SHA256(hash))) =
- (import.mode, &import.hash)
+ (import.import.mode, &import.import.hash)
{
- let actual_hash = typed.hir.to_expr_alpha().sha256_hash()?;
+ let expr = cx[result].hir.to_expr_alpha(cx);
+ let actual_hash = expr.sha256_hash()?;
if hash[..] != actual_hash[..] {
mkerr(
ErrorBuilder::new("hash mismatch")
- .span_err(span, "hash mismatch")
+ .span_err(import.span.clone(), "hash mismatch")
.note(format!("Expected sha256:{}", hex::encode(hash)))
.note(format!(
"Found sha256:{}",
@@ -332,127 +369,204 @@ fn desugar(expr: &Expr) -> Cow<'_, Expr> {
}
}
-/// Traverse the expression, handling import alternatives and passing
-/// found imports to the provided function. Also resolving names.
-fn traverse_resolve_expr(
+/// Fetch the import and store the result in the global context.
+fn fetch_import<'cx>(
+ env: &mut ImportEnv<'cx>,
+ import_id: ImportId<'cx>,
+) -> Result<ImportResultId<'cx>, Error> {
+ let cx = env.cx();
+ let import = &cx[import_id].import;
+ let span = cx[import_id].span.clone();
+ let location = cx[import_id].base_location.chain(import)?;
+
+ // If the import is in the in-memory cache, or the hash is in the on-disk cache, return
+ // the cached contents.
+ if let Some(res_id) = env.get_from_mem_cache(&location) {
+ // The same location may be used with different or no hashes. Thus we need to check
+ // the hashes every time.
+ env.check_hash(import_id, res_id)?;
+ env.write_to_disk_cache(&import.hash, res_id);
+ return Ok(res_id);
+ }
+ if let Some(typed) = env.get_from_disk_cache(&import.hash) {
+ // No need to check the hash, it was checked before reading the file.
+ // We also don't write to the in-memory cache, because the location might be completely
+ // unrelated to the cached file (e.g. `missing sha256:...` is valid).
+ // This actually means that importing many times a same hashed import will take
+ // longer than importing many times a same non-hashed import.
+ let res_id = cx.push_import_result(typed);
+ return Ok(res_id);
+ }
+
+ // Resolve this import, making sure that recursive imports don't cycle back to the
+ // current one.
+ let res = env.with_cycle_detection(location.clone(), |env| {
+ location.fetch(env, span.clone())
+ });
+ let typed = match res {
+ Ok(typed) => typed,
+ Err(e) => mkerr(
+ ErrorBuilder::new("error")
+ .span_err(span.clone(), e.to_string())
+ .format(),
+ )?,
+ };
+
+ // Add the resolved import to the caches
+ let res_id = cx.push_import_result(typed);
+ env.check_hash(import_id, res_id)?;
+ env.write_to_disk_cache(&import.hash, res_id);
+ // Cache the mapping from this location to the result.
+ env.write_to_mem_cache(location, res_id);
+
+ Ok(res_id)
+}
+
+/// Part of a tree of imports.
+#[derive(Debug, Clone, Copy)]
+pub enum ImportNode<'cx> {
+ Import(ImportId<'cx>),
+ Alternative(ImportAlternativeId<'cx>),
+}
+
+/// Traverse the expression and replace each import and import alternative by an id into the global
+/// context. The ids are also accumulated into `nodes` so that we can resolve them afterwards.
+fn traverse_accumulate<'cx>(
+ env: &mut ImportEnv<'cx>,
name_env: &mut NameEnv,
+ nodes: &mut Vec<ImportNode<'cx>>,
+ base_location: &ImportLocation,
expr: &Expr,
- f: &mut impl FnMut(Import, Span) -> Result<Typed, Error>,
-) -> Result<Hir, Error> {
+) -> Hir<'cx> {
+ let cx = env.cx();
let expr = desugar(expr);
- Ok(match expr.kind() {
+ let kind = match expr.kind() {
ExprKind::Var(var) => match name_env.unlabel_var(&var) {
- Some(v) => Hir::new(HirKind::Var(v), expr.span()),
- None => mkerr(
- ErrorBuilder::new(format!("unbound variable `{}`", var))
- .span_err(expr.span(), "not found in this scope")
- .format(),
- )?,
+ Some(v) => HirKind::Var(v),
+ None => HirKind::MissingVar(var.clone()),
},
ExprKind::Op(OpKind::BinOp(BinOp::ImportAlt, l, r)) => {
- match traverse_resolve_expr(name_env, l, f) {
- Ok(l) => l,
- Err(_) => {
- match traverse_resolve_expr(name_env, r, f) {
- Ok(r) => r,
- // TODO: keep track of the other error too
- Err(e) => return Err(e),
- }
- }
- }
+ let mut imports_l = Vec::new();
+ let l = traverse_accumulate(
+ env,
+ name_env,
+ &mut imports_l,
+ base_location,
+ l,
+ );
+ let mut imports_r = Vec::new();
+ let r = traverse_accumulate(
+ env,
+ name_env,
+ &mut imports_r,
+ base_location,
+ r,
+ );
+ let alt =
+ cx.push_import_alternative(imports_l.into(), imports_r.into());
+ nodes.push(ImportNode::Alternative(alt));
+ HirKind::ImportAlternative(alt, l, r)
}
kind => {
- let kind = kind.traverse_ref_maybe_binder(|l, e| {
+ let kind = kind.map_ref_maybe_binder(|l, e| {
if let Some(l) = l {
name_env.insert_mut(l);
}
- let hir = traverse_resolve_expr(name_env, e, f)?;
+ let hir =
+ traverse_accumulate(env, name_env, nodes, base_location, e);
if l.is_some() {
name_env.remove_mut();
}
- Ok::<_, Error>(hir)
- })?;
- let kind = match kind {
+ hir
+ });
+ match kind {
ExprKind::Import(import) => {
// TODO: evaluate import headers
- let import = import.traverse_ref(|_| Ok::<_, Error>(()))?;
- let imported = f(import, expr.span())?;
- HirKind::Import(imported.hir, imported.ty)
+ let import = import.map_ref(|_| ());
+ let import_id = cx.push_import(
+ base_location.clone(),
+ import,
+ expr.span(),
+ );
+ nodes.push(ImportNode::Import(import_id));
+ HirKind::Import(import_id)
}
kind => HirKind::Expr(kind),
- };
- Hir::new(kind, expr.span())
+ }
}
- })
+ };
+ Hir::new(kind, expr.span())
}
-fn resolve_with_env(
- env: &mut ImportEnv,
+/// Take a list of nodes and recursively resolve them.
+fn resolve_nodes<'cx>(
+ env: &mut ImportEnv<'cx>,
+ nodes: &[ImportNode<'cx>],
+) -> Result<(), Error> {
+ for &node in nodes {
+ match node {
+ ImportNode::Import(import) => {
+ let res_id = fetch_import(env, import)?;
+ env.cx()[import].set_resultid(res_id);
+ }
+ ImportNode::Alternative(alt) => {
+ let alt = &env.cx()[alt];
+ if resolve_nodes(env, &alt.left_imports).is_ok() {
+ alt.set_selected(true);
+ } else {
+ resolve_nodes(env, &alt.right_imports)?;
+ alt.set_selected(false);
+ }
+ }
+ }
+ }
+ Ok(())
+}
+
+fn resolve_with_env<'cx>(
+ env: &mut ImportEnv<'cx>,
parsed: Parsed,
-) -> Result<Resolved, Error> {
+) -> Result<Resolved<'cx>, Error> {
let Parsed(expr, base_location) = parsed;
- let resolved = traverse_resolve_expr(
+ let mut nodes = Vec::new();
+ // First we collect all imports.
+ let resolved = traverse_accumulate(
+ env,
&mut NameEnv::new(),
+ &mut nodes,
+ &base_location,
&expr,
- &mut |import, span| {
- let location = base_location.chain(&import)?;
-
- // If the import is in the in-memory cache, or the hash is in the on-disk cache, return
- // the cached contents.
- if let Some(typed) = env.get_from_mem_cache(&location) {
- // The same location may be used with different or no hashes. Thus we need to check
- // the hashes every time.
- check_hash(&import, &typed, span)?;
- env.write_to_disk_cache(&import.hash, &typed);
- return Ok(typed);
- }
- if let Some(typed) = env.get_from_disk_cache(&import.hash) {
- // No need to check the hash, it was checked before reading the file. We also don't
- // write to the in-memory cache, because the location might be completely unrelated
- // to the cached file (e.g. `missing sha256:...` is valid).
- // This actually means that importing many times a same hashed import will take
- // longer than importing many times a same non-hashed import.
- return Ok(typed);
- }
-
- // Resolve this import, making sure that recursive imports don't cycle back to the
- // current one.
- let res = env.with_cycle_detection(location.clone(), |env| {
- location.fetch(env, span.clone())
- });
- let typed = match res {
- Ok(typed) => typed,
- Err(e) => mkerr(
- ErrorBuilder::new("error")
- .span_err(span.clone(), e.to_string())
- .format(),
- )?,
- };
-
- // Add the resolved import to the caches
- check_hash(&import, &typed, span)?;
- env.write_to_disk_cache(&import.hash, &typed);
- env.write_to_mem_cache(location, typed.clone());
- Ok(typed)
- },
- )?;
+ );
+ // Then we resolve them and choose sides for the alternatives.
+ resolve_nodes(env, &nodes)?;
Ok(Resolved(resolved))
}
-pub fn resolve(parsed: Parsed) -> Result<Resolved, Error> {
- resolve_with_env(&mut ImportEnv::new(), parsed)
+/// Resolves all imports and names. Returns errors if importing failed. Name errors are deferred to
+/// typechecking.
+pub fn resolve<'cx>(
+ cx: Ctxt<'cx>,
+ parsed: Parsed,
+) -> Result<Resolved<'cx>, Error> {
+ parsed.resolve_with_env(&mut ImportEnv::new(cx))
}
-pub fn skip_resolve_expr(expr: &Expr) -> Result<Hir, Error> {
- traverse_resolve_expr(&mut NameEnv::new(), expr, &mut |import, _span| {
- Err(ImportError::UnexpectedImport(import).into())
- })
+/// Resolves names, and errors if we find any imports.
+pub fn skip_resolve<'cx>(
+ cx: Ctxt<'cx>,
+ parsed: Parsed,
+) -> Result<Resolved<'cx>, Error> {
+ let parsed = Parsed::from_expr_without_imports(parsed.0);
+ Ok(resolve(cx, parsed)?)
}
-pub fn skip_resolve(parsed: Parsed) -> Result<Resolved, Error> {
- let Parsed(expr, _) = parsed;
- let resolved = skip_resolve_expr(&expr)?;
- Ok(Resolved(resolved))
+impl Parsed {
+ fn resolve_with_env<'cx>(
+ self,
+ env: &mut ImportEnv<'cx>,
+ ) -> Result<Resolved<'cx>, Error> {
+ resolve_with_env(env, self)
+ }
}
pub trait Canonicalize {