3 files changed, 84 insertions, 2 deletions

diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 4411715de..f156e3f07 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -52,7 +52,7 @@ use crate::{
     db::{HirDatabase, DefDatabase},
     name::{AsName, KnownName},
     source_id::{FileAstId, AstId},
-    resolve::Resolver,
+    resolve::Resolver, resolve::ImportResolver,
 };
 
 pub use self::{
diff --git a/crates/ra_hir/src/resolve.rs b/crates/ra_hir/src/resolve.rs
index f2c85eb66..0f866e6c2 100644
--- a/crates/ra_hir/src/resolve.rs
+++ b/crates/ra_hir/src/resolve.rs
@@ -3,6 +3,8 @@ use std::sync::Arc;
 
 use rustc_hash::FxHashMap;
 
+use ra_syntax::SmolStr;
+
 use crate::{
     ModuleDef,
     code_model_api::Crate,
@@ -12,8 +14,12 @@ use crate::{
     generics::GenericParams,
     expr::{scope::{ExprScopes, ScopeId}, PatId},
     impl_block::ImplBlock,
+<<<<<<< HEAD
     path::Path,
     Trait
+=======
+    path::Path, Trait,
+>>>>>>> complete_import: add new import resolver infrastructure with some hardcoded importable name.
 };
 
 #[derive(Debug, Clone, Default)]
@@ -21,6 +27,12 @@ pub(crate) struct Resolver {
     scopes: Vec<Scope>,
 }
 
+#[derive(Debug, Clone, Default)]
+pub(crate) struct ImportResolver {
+    // todo: use fst crate or something like that
+    dummy_names: Vec<(SmolStr, Vec<SmolStr>)>,
+}
+
 // FIXME how to store these best
 #[derive(Debug, Clone)]
 pub(crate) struct ModuleItemMap {
@@ -309,3 +321,56 @@ impl Scope {
         }
     }
 }
+
+impl ImportResolver {
+    pub(crate) fn new() -> Self {
+        let dummy_names = vec![
+            (SmolStr::new("fmt"), vec![SmolStr::new("std"), SmolStr::new("fmt")]),
+            (SmolStr::new("io"), vec![SmolStr::new("std"), SmolStr::new("io")]),
+            (SmolStr::new("iter"), vec![SmolStr::new("std"), SmolStr::new("iter")]),
+            (SmolStr::new("hash"), vec![SmolStr::new("std"), SmolStr::new("hash")]),
+            (
+                SmolStr::new("Debug"),
+                vec![SmolStr::new("std"), SmolStr::new("fmt"), SmolStr::new("Debug")],
+            ),
+            (
+                SmolStr::new("Display"),
+                vec![SmolStr::new("std"), SmolStr::new("fmt"), SmolStr::new("Display")],
+            ),
+            (
+                SmolStr::new("Hash"),
+                vec![SmolStr::new("std"), SmolStr::new("hash"), SmolStr::new("Hash")],
+            ),
+            (
+                SmolStr::new("Hasher"),
+                vec![SmolStr::new("std"), SmolStr::new("hash"), SmolStr::new("Hasher")],
+            ),
+            (
+                SmolStr::new("Iterator"),
+                vec![SmolStr::new("std"), SmolStr::new("iter"), SmolStr::new("Iterator")],
+            ),
+        ];
+
+        ImportResolver { dummy_names }
+    }
+
+    // Returns a map of importable items filtered by name.
+    // The map associates item name with its full path.
+    // todo: should return Resolutions
+    pub(crate) fn all_names(
+        &self,
+        _db: &impl HirDatabase,
+        name: &Name,
+    ) -> FxHashMap<SmolStr, Vec<SmolStr>> {
+        let name = name.to_smolstr();
+        if name.len() > 1 {
+            self.dummy_names
+                .iter()
+                .filter(|(n, _)| n.as_str().contains(name.as_str()))
+                .cloned()
+                .collect()
+        } else {
+            FxHashMap::default()
+        }
+    }
+}
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index f1bb13bc6..a6f0ab289 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -14,14 +14,19 @@ use ra_syntax::{
     ast::{self, AstNode, NameOwner},
     algo::find_node_at_offset,
     SyntaxKind::*,
+    SmolStr,
 };
 
 use crate::{
     HirDatabase, Function, Struct, Enum, Const, Static, Either, DefWithBody, PerNs, Name,
+<<<<<<< HEAD
     AsName, Module, HirFileId, Crate, Trait, Resolver, Ty,
+=======
+    AsName, Module, HirFileId, Crate, Trait, Resolver, ImportResolver,
+>>>>>>> complete_import: add new import resolver infrastructure with some hardcoded importable name.
     expr::{BodySourceMap, scope::{ScopeId, ExprScopes}},
     ids::LocationCtx,
-    expr, AstId
+    expr, AstId,
 };
 
 /// Locates the module by `FileId`. Picks topmost module in the file.
@@ -170,6 +175,7 @@ fn def_with_body_from_child_node(
 #[derive(Debug)]
 pub struct SourceAnalyzer {
     resolver: Resolver,
+    import_resolver: ImportResolver,
     body_source_map: Option<Arc<BodySourceMap>>,
     infer: Option<Arc<crate::ty::InferenceResult>>,
     scopes: Option<Arc<crate::expr::ExprScopes>>,
@@ -217,6 +223,7 @@ impl SourceAnalyzer {
         offset: Option<TextUnit>,
     ) -> SourceAnalyzer {
         let def_with_body = def_with_body_from_child_node(db, file_id, node);
+        let import_resolver = ImportResolver::new();
         if let Some(def) = def_with_body {
             let source_map = def.body_source_map(db);
             let scopes = db.expr_scopes(def);
@@ -227,6 +234,7 @@ impl SourceAnalyzer {
             let resolver = expr::resolver_for_scope(def.body(db), db, scope);
             SourceAnalyzer {
                 resolver,
+                import_resolver,
                 body_source_map: Some(source_map),
                 infer: Some(def.infer(db)),
                 scopes: Some(scopes),
@@ -237,6 +245,7 @@ impl SourceAnalyzer {
                     .ancestors()
                     .find_map(|node| try_get_resolver_for_node(db, file_id, node))
                     .unwrap_or_default(),
+                import_resolver,
                 body_source_map: None,
                 infer: None,
                 scopes: None,
@@ -323,6 +332,14 @@ impl SourceAnalyzer {
         self.resolver.all_names(db)
     }
 
+    pub fn all_import_names(
+        &self,
+        db: &impl HirDatabase,
+        name: &Name,
+    ) -> FxHashMap<SmolStr, Vec<SmolStr>> {
+        self.import_resolver.all_names(db, name)
+    }
+
     pub fn find_all_refs(&self, pat: &ast::BindPat) -> Vec<ReferenceDescriptor> {
         // FIXME: at least, this should work with any DefWithBody, but ideally
         // this should be hir-based altogether