1 files changed, 46 insertions, 51 deletions

diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index d426d275e..7ca1ff595 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -35,16 +35,17 @@ use crate::{
     expr::{Body, Expr, BindingAnnotation, Literal, ExprId, Pat, PatId, UnaryOp, BinaryOp, Statement, FieldPat,Array, self},
     generics::{GenericParams, HasGenericParams},
     path::{GenericArgs, GenericArg},
+    ModuleDef,
     adt::VariantDef,
     resolve::{Resolver, Resolution},
     nameres::Namespace,
+    ty::infer::diagnostics::InferenceDiagnostic,
     diagnostics::DiagnosticSink,
 };
 use super::{
     Ty, TypableDef, Substs, primitive, op, ApplicationTy, TypeCtor, CallableDef, TraitRef,
     traits::{ Solution, Obligation, Guidance},
 };
-use self::diagnostics::InferenceDiagnostic;
 
 /// The entry point of type inference.
 pub fn infer(db: &impl HirDatabase, def: DefWithBody) -> Arc<InferenceResult> {
@@ -462,28 +463,25 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         let mut actual_def_ty: Option<Ty> = None;
 
         // resolve intermediate segments
-        for segment in &path.segments[remaining_index..] {
+        for (i, segment) in path.segments[remaining_index..].iter().enumerate() {
             let ty = match resolved {
                 Resolution::Def(def) => {
                     // FIXME resolve associated items from traits as well
                     let typable: Option<TypableDef> = def.into();
                     let typable = typable?;
 
-                    let mut ty = self.db.type_for_def(typable, Namespace::Types);
+                    let ty = self.db.type_for_def(typable, Namespace::Types);
 
-                    if remaining_index > 0 {
-                        // For example, this substs will take `Gen::*<u32>*::make`
-                        let substs = Ty::substs_from_path_segment(
-                            self.db,
-                            &self.resolver,
-                            &path.segments[remaining_index - 1],
-                            typable,
-                        );
-
-                        ty = ty.subst(&substs);
-                    }
+                    // For example, this substs will take `Gen::*<u32>*::make`
+                    assert!(remaining_index > 0);
+                    let substs = Ty::substs_from_path_segment(
+                        self.db,
+                        &self.resolver,
+                        &path.segments[remaining_index + i - 1],
+                        typable,
+                    );
 
-                    ty
+                    ty.subst(&substs)
                 }
                 Resolution::LocalBinding(_) => {
                     // can't have a local binding in an associated item path
@@ -541,45 +539,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
         match resolved {
             Resolution::Def(def) => {
-                // Helpper function for finding self types
-                let find_self_types = || -> Option<Substs> {
-                    let actual_def_ty = actual_def_ty?;
-
-                    if let crate::ModuleDef::Function(func) = def {
-                        // We only do the infer if parent has generic params
-                        let gen = func.generic_params(self.db);
-                        if gen.count_parent_params() == 0 {
-                            return None;
-                        }
-
-                        let impl_block = func.impl_block(self.db)?.target_ty(self.db);
-                        let impl_block_substs = impl_block.substs()?;
-                        let actual_substs = actual_def_ty.substs()?;
-
-                        let mut new_substs = vec![Ty::Unknown; gen.count_parent_params()];
-
-                        // The following code *link up* the function actual parma type
-                        // and impl_block type param index
-                        impl_block_substs.iter().zip(actual_substs.iter()).for_each(
-                            |(param, pty)| {
-                                if let Ty::Param { idx, .. } = param {
-                                    if let Some(s) = new_substs.get_mut(*idx as usize) {
-                                        *s = pty.clone();
-                                    }
-                                }
-                            },
-                        );
-
-                        Some(Substs(new_substs.into()))
-                    } else {
-                        None
-                    }
-                };
-
                 let typable: Option<TypableDef> = def.into();
                 let typable = typable?;
                 let mut ty = self.db.type_for_def(typable, Namespace::Values);
-                if let Some(sts) = find_self_types() {
+                if let Some(sts) = self.find_self_types(&def, actual_def_ty) {
                     ty = ty.subst(&sts);
                 }
 
@@ -604,6 +567,38 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         }
     }
 
+    fn find_self_types(&self, def: &ModuleDef, actual_def_ty: Option<Ty>) -> Option<Substs> {
+        let actual_def_ty = actual_def_ty?;
+
+        if let crate::ModuleDef::Function(func) = def {
+            // We only do the infer if parent has generic params
+            let gen = func.generic_params(self.db);
+            if gen.count_parent_params() == 0 {
+                return None;
+            }
+
+            let impl_block = func.impl_block(self.db)?.target_ty(self.db);
+            let impl_block_substs = impl_block.substs()?;
+            let actual_substs = actual_def_ty.substs()?;
+
+            let mut new_substs = vec![Ty::Unknown; gen.count_parent_params()];
+
+            // The following code *link up* the function actual parma type
+            // and impl_block type param index
+            impl_block_substs.iter().zip(actual_substs.iter()).for_each(|(param, pty)| {
+                if let Ty::Param { idx, .. } = param {
+                    if let Some(s) = new_substs.get_mut(*idx as usize) {
+                        *s = pty.clone();
+                    }
+                }
+            });
+
+            Some(Substs(new_substs.into()))
+        } else {
+            None
+        }
+    }
+
     fn resolve_variant(&mut self, path: Option<&Path>) -> (Ty, Option<VariantDef>) {
         let path = match path {
             Some(path) => path,