introduce SourceAnalyzer

15 files changed, 206 insertions, 187 deletions

diff --git a/crates/ra_assists/src/add_explicit_type.rs b/crates/ra_assists/src/add_explicit_type.rs
index 1dc59bb87..c50db4e21 100644
--- a/crates/ra_assists/src/add_explicit_type.rs
+++ b/crates/ra_assists/src/add_explicit_type.rs
@@ -1,7 +1,6 @@
 use hir::{
     HirDisplay, Ty,
     db::HirDatabase,
-    source_binder::function_from_child_node,
 };
 use ra_syntax::{
     SyntaxKind,
@@ -30,11 +29,8 @@ pub(crate) fn add_explicit_type(mut ctx: AssistCtx<impl HirDatabase>) -> Option<
     }
     // Infer type
     let db = ctx.db;
-    let func = function_from_child_node(db, ctx.frange.file_id, pat.syntax())?;
-    let inference_res = func.infer(db);
-    let source_map = func.body_source_map(db);
-    let expr_id = source_map.node_expr(expr.into())?;
-    let ty = inference_res[expr_id].clone();
+    let analyzer = hir::SourceAnalyser::new(db, ctx.frange.file_id, stmt.syntax());
+    let ty = analyzer.type_of(db, expr)?;
     // Assist not applicable if the type is unknown
     if is_unknown(&ty) {
         return None;
diff --git a/crates/ra_assists/src/add_missing_impl_members.rs b/crates/ra_assists/src/add_missing_impl_members.rs
index 19a2d05bc..0b2127e11 100644
--- a/crates/ra_assists/src/add_missing_impl_members.rs
+++ b/crates/ra_assists/src/add_missing_impl_members.rs
@@ -2,7 +2,6 @@ use std::fmt::Write;
 
 use crate::{Assist, AssistId, AssistCtx};
 
-use hir::Resolver;
 use hir::db::HirDatabase;
 use ra_syntax::{SmolStr, SyntaxKind, TextRange, TextUnit, TreeArc};
 use ra_syntax::ast::{self, AstNode, AstToken, FnDef, ImplItem, ImplItemKind, NameOwner};
@@ -46,9 +45,9 @@ fn add_missing_impl_members_inner(
     let trait_def = {
         let file_id = ctx.frange.file_id;
         let position = FilePosition { file_id, offset: impl_node.syntax().range().start() };
-        let resolver = hir::source_binder::resolver_for_position(ctx.db, position);
+        let analyser = hir::SourceAnalyser::new(ctx.db, position.file_id, impl_node.syntax());
 
-        resolve_target_trait_def(ctx.db, &resolver, impl_node)?
+        resolve_target_trait_def(ctx.db, &analyser, impl_node)?
     };
 
     let missing_fns: Vec<_> = {
@@ -122,14 +121,14 @@ fn add_missing_impl_members_inner(
 /// implemented) to a `ast::TraitDef`.
 fn resolve_target_trait_def(
     db: &impl HirDatabase,
-    resolver: &Resolver,
+    binder: &hir::SourceAnalyser,
     impl_block: &ast::ImplBlock,
 ) -> Option<TreeArc<ast::TraitDef>> {
-    let ast_path = impl_block.target_trait().map(AstNode::syntax).and_then(ast::PathType::cast)?;
-    let hir_path = ast_path.path().and_then(hir::Path::from_ast)?;
+    let ast_path =
+        impl_block.target_trait().map(AstNode::syntax).and_then(ast::PathType::cast)?.path()?;
 
-    match resolver.resolve_path(db, &hir_path).take_types() {
-        Some(hir::Resolution::Def(hir::ModuleDef::Trait(def))) => Some(def.source(db).1),
+    match binder.resolve_path(db, &ast_path) {
+        Some(hir::PathResolution::Def(hir::ModuleDef::Trait(def))) => Some(def.source(db).1),
         _ => None,
     }
 }
diff --git a/crates/ra_assists/src/fill_match_arms.rs b/crates/ra_assists/src/fill_match_arms.rs
index da67ab667..050b1c73f 100644
--- a/crates/ra_assists/src/fill_match_arms.rs
+++ b/crates/ra_assists/src/fill_match_arms.rs
@@ -1,7 +1,7 @@
 use std::fmt::Write;
 
 use hir::{
-    AdtDef, FieldSource, source_binder,
+    AdtDef, FieldSource,
     db::HirDatabase,
 };
 use ra_syntax::ast::{self, AstNode};
@@ -20,12 +20,8 @@ pub(crate) fn fill_match_arms(mut ctx: AssistCtx<impl HirDatabase>) -> Option<As
     }
 
     let expr = match_expr.expr()?;
-    let function =
-        source_binder::function_from_child_node(ctx.db, ctx.frange.file_id, expr.syntax())?;
-    let infer_result = function.infer(ctx.db);
-    let source_map = function.body_source_map(ctx.db);
-    let node_expr = source_map.node_expr(expr)?;
-    let match_expr_ty = infer_result[node_expr].clone();
+    let analyzer = hir::SourceAnalyser::new(ctx.db, ctx.frange.file_id, expr.syntax());
+    let match_expr_ty = analyzer.type_of(ctx.db, expr)?;
     let enum_def = match_expr_ty.autoderef(ctx.db).find_map(|ty| match ty.as_adt() {
         Some((AdtDef::Enum(e), _)) => Some(e),
         _ => None,
diff --git a/crates/ra_assists/src/fill_struct_fields.rs b/crates/ra_assists/src/fill_struct_fields.rs
index c7790dc72..e23cccbb8 100644
--- a/crates/ra_assists/src/fill_struct_fields.rs
+++ b/crates/ra_assists/src/fill_struct_fields.rs
@@ -1,6 +1,6 @@
 use std::fmt::Write;
 
-use hir::{AdtDef, db::HirDatabase, source_binder::function_from_child_node};
+use hir::{AdtDef, db::HirDatabase};
 
 use ra_syntax::ast::{self, AstNode};
 
@@ -51,15 +51,12 @@ where
     }
 
     fn evaluate_struct_def_fields(&mut self) -> Option<()> {
-        let function = function_from_child_node(
+        let analyzer = hir::SourceAnalyser::new(
             self.ctx.db,
             self.ctx.frange.file_id,
             self.struct_lit.syntax(),
-        )?;
-        let infer_result = function.infer(self.ctx.db);
-        let source_map = function.body_source_map(self.ctx.db);
-        let node_expr = source_map.node_expr(self.struct_lit.into())?;
-        let struct_lit_ty = infer_result[node_expr].clone();
+        );
+        let struct_lit_ty = analyzer.type_of(self.ctx.db, self.struct_lit.into())?;
         let struct_def = match struct_lit_ty.as_adt() {
             Some((AdtDef::Struct(s), _)) => s,
             _ => return None,
diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index f13a6b37a..660edf006 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -450,10 +450,6 @@ impl DefWithBody {
         db.infer(*self)
     }
 
-    pub fn body_source_map(&self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
-        db.body_with_source_map(*self).1
-    }
-
     pub fn body(&self, db: &impl HirDatabase) -> Arc<Body> {
         db.body_hir(*self)
     }
@@ -523,7 +519,7 @@ impl Function {
         self.signature(db).name.clone()
     }
 
-    pub fn body_source_map(&self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
+    pub(crate) fn body_source_map(&self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
         db.body_with_source_map((*self).into()).1
     }
 
@@ -606,7 +602,7 @@ impl Const {
         db.infer((*self).into())
     }
 
-    pub fn body_source_map(&self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
+    pub(crate) fn body_source_map(&self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
         db.body_with_source_map((*self).into()).1
     }
 
@@ -679,7 +675,7 @@ impl Static {
         db.infer((*self).into())
     }
 
-    pub fn body_source_map(&self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
+    pub(crate) fn body_source_map(&self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
         db.body_with_source_map((*self).into()).1
     }
 }
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index a8e115e47..3806a3605 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -117,31 +117,27 @@ impl Index<PatId> for Body {
 }
 
 impl BodySourceMap {
-    pub fn expr_syntax(&self, expr: ExprId) -> Option<SyntaxNodePtr> {
+    pub(crate) fn expr_syntax(&self, expr: ExprId) -> Option<SyntaxNodePtr> {
         self.expr_map_back.get(expr).cloned()
     }
 
-    pub fn syntax_expr(&self, ptr: SyntaxNodePtr) -> Option<ExprId> {
+    pub(crate) fn syntax_expr(&self, ptr: SyntaxNodePtr) -> Option<ExprId> {
         self.expr_map.get(&ptr).cloned()
     }
 
-    pub fn node_expr(&self, node: &ast::Expr) -> Option<ExprId> {
+    pub(crate) fn node_expr(&self, node: &ast::Expr) -> Option<ExprId> {
         self.expr_map.get(&SyntaxNodePtr::new(node.syntax())).cloned()
     }
 
-    pub fn pat_syntax(&self, pat: PatId) -> Option<PatPtr> {
+    pub(crate) fn pat_syntax(&self, pat: PatId) -> Option<PatPtr> {
         self.pat_map_back.get(pat).cloned()
     }
 
-    pub fn syntax_pat(&self, ptr: PatPtr) -> Option<PatId> {
-        self.pat_map.get(&ptr).cloned()
-    }
-
-    pub fn node_pat(&self, node: &ast::Pat) -> Option<PatId> {
+    pub(crate) fn node_pat(&self, node: &ast::Pat) -> Option<PatId> {
         self.pat_map.get(&Either::A(AstPtr::new(node))).cloned()
     }
 
-    pub fn field_syntax(&self, expr: ExprId, field: usize) -> AstPtr<ast::NamedField> {
+    pub(crate) fn field_syntax(&self, expr: ExprId, field: usize) -> AstPtr<ast::NamedField> {
         self.field_map[&(expr, field)].clone()
     }
 }
diff --git a/crates/ra_hir/src/expr/scope.rs b/crates/ra_hir/src/expr/scope.rs
index 725b6c00e..404c979eb 100644
--- a/crates/ra_hir/src/expr/scope.rs
+++ b/crates/ra_hir/src/expr/scope.rs
@@ -109,7 +109,7 @@ impl ExprScopes {
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ScopesWithSourceMap {
-    pub source_map: Arc<BodySourceMap>,
+    pub(crate) source_map: Arc<BodySourceMap>,
     pub scopes: Arc<ExprScopes>,
 }
 
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 0881939a2..59b402c57 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -66,6 +66,7 @@ pub use self::{
     adt::AdtDef,
     expr::{ExprScopes, ScopesWithSourceMap, ScopeEntryWithSyntax},
     resolve::{Resolver, Resolution},
+    source_binder::{SourceAnalyser, PathResolution},
 };
 
 pub use self::code_model_api::{
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 182ed4c91..79e304383 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -5,15 +5,17 @@
 ///
 /// So, this modules should not be used during hir construction, it exists
 /// purely for "IDE needs".
+use std::sync::Arc;
+
 use ra_db::{FileId, FilePosition};
 use ra_syntax::{
-    SyntaxNode,
+    SyntaxNode, AstPtr,
     ast::{self, AstNode, NameOwner},
     algo::{find_node_at_offset, find_token_at_offset},
 };
 
 use crate::{
-    HirDatabase, Function, Struct, Enum,Const,Static,
+    HirDatabase, Function, Struct, Enum, Const, Static, Either,
     AsName, Module, HirFileId, Crate, Trait, Resolver,
     ids::LocationCtx,
     expr, AstId
@@ -258,3 +260,97 @@ fn try_get_resolver_for_node(
         None
     }
 }
+
+// Name is bad, don't use inside HIR
+#[derive(Debug)]
+pub struct SourceAnalyser {
+    resolver: Resolver,
+    body_source_map: Option<Arc<crate::expr::BodySourceMap>>,
+    infer: Option<Arc<crate::ty::InferenceResult>>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum PathResolution {
+    /// An item
+    Def(crate::ModuleDef),
+    /// A local binding (only value namespace)
+    LocalBinding(crate::expr::PatId),
+    /// A generic parameter
+    GenericParam(u32),
+    SelfType(crate::ImplBlock),
+    AssocItem(crate::ImplItem),
+}
+
+impl SourceAnalyser {
+    pub fn new(db: &impl HirDatabase, file_id: FileId, node: &SyntaxNode) -> SourceAnalyser {
+        let resolver = resolver_for_node(db, file_id, node);
+        let function = function_from_child_node(db, file_id, node);
+        if let Some(function) = function {
+            SourceAnalyser {
+                resolver,
+                body_source_map: Some(function.body_source_map(db)),
+                infer: Some(function.infer(db)),
+            }
+        } else {
+            SourceAnalyser { resolver, body_source_map: None, infer: None }
+        }
+    }
+
+    pub fn type_of(&self, _db: &impl HirDatabase, expr: &ast::Expr) -> Option<crate::Ty> {
+        let expr_id = self.body_source_map.as_ref()?.node_expr(expr)?;
+        Some(self.infer.as_ref()?[expr_id].clone())
+    }
+
+    pub fn type_of_pat(&self, _db: &impl HirDatabase, pat: &ast::Pat) -> Option<crate::Ty> {
+        let pat_id = self.body_source_map.as_ref()?.node_pat(pat)?;
+        Some(self.infer.as_ref()?[pat_id].clone())
+    }
+
+    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
+        let expr_id = self.body_source_map.as_ref()?.node_expr(call.into())?;
+        self.infer.as_ref()?.method_resolution(expr_id)
+    }
+
+    pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<crate::StructField> {
+        let expr_id = self.body_source_map.as_ref()?.node_expr(field.into())?;
+        self.infer.as_ref()?.field_resolution(expr_id)
+    }
+
+    pub fn resolve_path(&self, db: &impl HirDatabase, path: &ast::Path) -> Option<PathResolution> {
+        if let Some(path_expr) = path.syntax().parent().and_then(ast::PathExpr::cast) {
+            let expr_id = self.body_source_map.as_ref()?.node_expr(path_expr.into())?;
+            if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_expr(expr_id) {
+                return Some(PathResolution::AssocItem(assoc));
+            }
+        }
+        if let Some(path_pat) = path.syntax().parent().and_then(ast::PathPat::cast) {
+            let pat_id = self.body_source_map.as_ref()?.node_pat(path_pat.into())?;
+            if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_pat(pat_id) {
+                return Some(PathResolution::AssocItem(assoc));
+            }
+        }
+        let hir_path = crate::Path::from_ast(path)?;
+        let res = self.resolver.resolve_path(db, &hir_path);
+        let res = res.clone().take_types().or_else(|| res.take_values())?;
+        Some(res.into())
+    }
+
+    pub fn pat_syntax(
+        &self,
+        _db: &impl HirDatabase,
+        pat: crate::expr::PatId,
+    ) -> Option<Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>> {
+        self.body_source_map.as_ref()?.pat_syntax(pat)
+    }
+}
+
+impl From<crate::Resolution> for PathResolution {
+    fn from(res: crate::Resolution) -> PathResolution {
+        match res {
+            crate::Resolution::Def(it) => PathResolution::Def(it),
+            crate::Resolution::LocalBinding(it) => PathResolution::LocalBinding(it),
+            crate::Resolution::GenericParam(it) => PathResolution::GenericParam(it),
+            crate::Resolution::SelfType(it) => PathResolution::SelfType(it),
+        }
+    }
+}
diff --git a/crates/ra_ide_api/src/completion/complete_dot.rs b/crates/ra_ide_api/src/completion/complete_dot.rs
index c093d5cfb..358057364 100644
--- a/crates/ra_ide_api/src/completion/complete_dot.rs
+++ b/crates/ra_ide_api/src/completion/complete_dot.rs
@@ -4,17 +4,10 @@ use crate::completion::{CompletionContext, Completions};
 
 /// Complete dot accesses, i.e. fields or methods (currently only fields).
 pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
-    let (function, receiver) = match (&ctx.function, ctx.dot_receiver) {
-        (Some(function), Some(receiver)) => (function, receiver),
-        _ => return,
-    };
-    let infer_result = function.infer(ctx.db);
-    let source_map = function.body_source_map(ctx.db);
-    let expr = match source_map.node_expr(receiver) {
-        Some(expr) => expr,
+    let receiver_ty = match ctx.dot_receiver.and_then(|it| ctx.analyzer.type_of(ctx.db, it)) {
+        Some(it) => it,
         None => return,
     };
-    let receiver_ty = infer_result[expr].clone();
     if !ctx.is_call {
         complete_fields(acc, ctx, receiver_ty.clone());
     }
diff --git a/crates/ra_ide_api/src/completion/complete_struct_literal.rs b/crates/ra_ide_api/src/completion/complete_struct_literal.rs
index f58bcd03e..48fbf67f7 100644
--- a/crates/ra_ide_api/src/completion/complete_struct_literal.rs
+++ b/crates/ra_ide_api/src/completion/complete_struct_literal.rs
@@ -4,17 +4,10 @@ use crate::completion::{CompletionContext, Completions};
 
 /// Complete fields in fields literals.
 pub(super) fn complete_struct_literal(acc: &mut Completions, ctx: &CompletionContext) {
-    let (function, struct_lit) = match (&ctx.function, ctx.struct_lit_syntax) {
-        (Some(function), Some(struct_lit)) => (function, struct_lit),
-        _ => return,
-    };
-    let infer_result = function.infer(ctx.db);
-    let source_map = function.body_source_map(ctx.db);
-    let expr = match source_map.node_expr(struct_lit.into()) {
-        Some(expr) => expr,
+    let ty = match ctx.struct_lit_syntax.and_then(|it| ctx.analyzer.type_of(ctx.db, it.into())) {
+        Some(it) => it,
         None => return,
     };
-    let ty = infer_result[expr].clone();
     let (adt, substs) = match ty.as_adt() {
         Some(res) => res,
         _ => return,
diff --git a/crates/ra_ide_api/src/completion/completion_context.rs b/crates/ra_ide_api/src/completion/completion_context.rs
index 65dffa470..ce21fca9b 100644
--- a/crates/ra_ide_api/src/completion/completion_context.rs
+++ b/crates/ra_ide_api/src/completion/completion_context.rs
@@ -14,6 +14,7 @@ use crate::{db, FilePosition};
 #[derive(Debug)]
 pub(crate) struct CompletionContext<'a> {
     pub(super) db: &'a db::RootDatabase,
+    pub(super) analyzer: hir::SourceAnalyser,
     pub(super) offset: TextUnit,
     pub(super) token: SyntaxToken<'a>,
     pub(super) resolver: Resolver,
@@ -50,8 +51,10 @@ impl<'a> CompletionContext<'a> {
         let resolver = source_binder::resolver_for_position(db, position);
         let module = source_binder::module_from_position(db, position);
         let token = find_token_at_offset(original_file.syntax(), position.offset).left_biased()?;
+        let analyzer = hir::SourceAnalyser::new(db, position.file_id, token.parent());
         let mut ctx = CompletionContext {
             db,
+            analyzer,
             token,
             offset: position.offset,
             resolver,
diff --git a/crates/ra_ide_api/src/display/navigation_target.rs b/crates/ra_ide_api/src/display/navigation_target.rs
index 3c518faf5..84645287d 100644
--- a/crates/ra_ide_api/src/display/navigation_target.rs
+++ b/crates/ra_ide_api/src/display/navigation_target.rs
@@ -1,11 +1,11 @@
 use ra_db::{FileId, SourceDatabase};
 use ra_syntax::{
-    SyntaxNode, SyntaxNodePtr, AstNode, SmolStr, TextRange, TreeArc,
+    SyntaxNode, AstNode, SmolStr, TextRange, TreeArc, AstPtr,
     SyntaxKind::{self, NAME},
     ast::{self, NameOwner, VisibilityOwner, TypeAscriptionOwner},
     algo::visit::{visitor, Visitor},
 };
-use hir::{ModuleSource, FieldSource, Name, ImplItem};
+use hir::{ModuleSource, FieldSource, ImplItem, Either};
 
 use crate::{FileSymbol, db::RootDatabase};
 
@@ -74,15 +74,25 @@ impl NavigationTarget {
         }
     }
 
-    pub(crate) fn from_scope_entry(
+    pub(crate) fn from_pat(
+        db: &RootDatabase,
         file_id: FileId,
-        name: Name,
-        ptr: SyntaxNodePtr,
+        pat: Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>,
     ) -> NavigationTarget {
+        let file = db.parse(file_id);
+        let (name, full_range) = match pat {
+            Either::A(pat) => match pat.to_node(&file).kind() {
+                ast::PatKind::BindPat(pat) => {
+                    return NavigationTarget::from_bind_pat(file_id, &pat)
+                }
+                _ => ("_".into(), pat.syntax_node_ptr().range()),
+            },
+            Either::B(slf) => ("self".into(), slf.syntax_node_ptr().range()),
+        };
         NavigationTarget {
             file_id,
-            name: name.to_string().into(),
-            full_range: ptr.range(),
+            name,
+            full_range,
             focus_range: None,
             kind: NAME,
             container_name: None,
@@ -229,6 +239,7 @@ impl NavigationTarget {
 
     /// Allows `NavigationTarget` to be created from a `NameOwner`
     pub(crate) fn from_named(file_id: FileId, node: &impl ast::NameOwner) -> NavigationTarget {
+        //FIXME: use `_` instead of empty string
         let name = node.name().map(|it| it.text().clone()).unwrap_or_default();
         let focus_range = node.name().map(|it| it.syntax().range());
         NavigationTarget::from_syntax(file_id, name, focus_range, node.syntax())
diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide_api/src/goto_definition.rs
index 60c1f5085..7f93f50c4 100644
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide_api/src/goto_definition.rs
@@ -5,7 +5,6 @@ use ra_syntax::{
     SyntaxNode,
 };
 use test_utils::tested_by;
-use hir::Resolution;
 
 use crate::{FilePosition, NavigationTarget, db::RootDatabase, RangeInfo};
 
@@ -48,127 +47,72 @@ pub(crate) fn reference_definition(
 ) -> ReferenceResult {
     use self::ReferenceResult::*;
 
-    let function = hir::source_binder::function_from_child_node(db, file_id, name_ref.syntax());
-
-    if let Some(function) = function {
-        // Check if it is a method
-        if let Some(method_call) = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast) {
-            tested_by!(goto_definition_works_for_methods);
-            let infer_result = function.infer(db);
-            let source_map = function.body_source_map(db);
-            let expr = ast::Expr::cast(method_call.syntax()).unwrap();
-            if let Some(func) =
-                source_map.node_expr(expr).and_then(|it| infer_result.method_resolution(it))
-            {
-                return Exact(NavigationTarget::from_function(db, func));
-            };
-        }
-        // It could also be a field access
-        if let Some(field_expr) = name_ref.syntax().parent().and_then(ast::FieldExpr::cast) {
-            tested_by!(goto_definition_works_for_fields);
-            let infer_result = function.infer(db);
-            let source_map = function.body_source_map(db);
-            let expr = ast::Expr::cast(field_expr.syntax()).unwrap();
-            if let Some(field) =
-                source_map.node_expr(expr).and_then(|it| infer_result.field_resolution(it))
-            {
-                return Exact(NavigationTarget::from_field(db, field));
-            };
-        }
+    let analyzer = hir::SourceAnalyser::new(db, file_id, name_ref.syntax());
 
-        // It could also be a named field
-        if let Some(field_expr) = name_ref.syntax().parent().and_then(ast::NamedField::cast) {
-            tested_by!(goto_definition_works_for_named_fields);
+    // Special cases:
 
-            let infer_result = function.infer(db);
-            let source_map = function.body_source_map(db);
+    // Check if it is a method
+    if let Some(method_call) = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast) {
+        tested_by!(goto_definition_works_for_methods);
+        if let Some(func) = analyzer.resolve_method_call(method_call) {
+            return Exact(NavigationTarget::from_function(db, func));
+        }
+    }
+    // It could also be a field access
+    if let Some(field_expr) = name_ref.syntax().parent().and_then(ast::FieldExpr::cast) {
+        tested_by!(goto_definition_works_for_fields);
+        if let Some(field) = analyzer.resolve_field(field_expr) {
+            return Exact(NavigationTarget::from_field(db, field));
+        };
+    }
 
-            let struct_lit = field_expr.syntax().ancestors().find_map(ast::StructLit::cast);
+    // It could also be a named field
+    if let Some(field_expr) = name_ref.syntax().parent().and_then(ast::NamedField::cast) {
+        tested_by!(goto_definition_works_for_named_fields);
 
-            if let Some(expr) = struct_lit.and_then(|lit| source_map.node_expr(lit.into())) {
-                let ty = infer_result[expr].clone();
-                if let Some((hir::AdtDef::Struct(s), _)) = ty.as_adt() {
-                    let hir_path = hir::Path::from_name_ref(name_ref);
-                    let hir_name = hir_path.as_ident().unwrap();
+        let struct_lit = field_expr.syntax().ancestors().find_map(ast::StructLit::cast);
 
-                    if let Some(field) = s.field(db, hir_name) {
-                        return Exact(NavigationTarget::from_field(db, field));
-                    }
+        if let Some(ty) = struct_lit.and_then(|lit| analyzer.type_of(db, lit.into())) {
+            if let Some((hir::AdtDef::Struct(s), _)) = ty.as_adt() {
+                let hir_path = hir::Path::from_name_ref(name_ref);
+                let hir_name = hir_path.as_ident().unwrap();
+
+                if let Some(field) = s.field(db, hir_name) {
+                    return Exact(NavigationTarget::from_field(db, field));
                 }
             }
         }
     }
 
-    // Try name resolution
-    let resolver = hir::source_binder::resolver_for_node(db, file_id, name_ref.syntax());
-    if let Some(path) =
-        name_ref.syntax().ancestors().find_map(ast::Path::cast).and_then(hir::Path::from_ast)
-    {
-        let resolved = resolver.resolve_path(db, &path);
-        match resolved.clone().take_types().or_else(|| resolved.take_values()) {
-            Some(Resolution::Def(def)) => return Exact(NavigationTarget::from_def(db, def)),
-            Some(Resolution::LocalBinding(pat)) => {
-                let body = resolver.body().expect("no body for local binding");
-                let source_map = body.owner().body_source_map(db);
-                let ptr = source_map.pat_syntax(pat).expect("pattern not found in syntax mapping");
-                let name =
-                    path.as_ident().cloned().expect("local binding from a multi-segment path");
-                let ptr = ptr.either(|it| it.into(), |it| it.into());
-                let nav = NavigationTarget::from_scope_entry(file_id, name, ptr);
-                return Exact(nav);
-            }
-            Some(Resolution::GenericParam(..)) => {
-                // FIXME: go to the generic param def
-            }
-            Some(Resolution::SelfType(impl_block)) => {
-                let ty = impl_block.target_ty(db);
-
-                if let Some((def_id, _)) = ty.as_adt() {
-                    return Exact(NavigationTarget::from_adt_def(db, def_id));
-                }
-            }
-            None => {
-                // If we failed to resolve then check associated items
-                if let Some(function) = function {
-                    // Resolve associated item for path expressions
-                    if let Some(path_expr) =
-                        name_ref.syntax().ancestors().find_map(ast::PathExpr::cast)
-                    {
-                        let infer_result = function.infer(db);
-                        let source_map = function.body_source_map(db);
-
-                        if let Some(expr) = ast::Expr::cast(path_expr.syntax()) {
-                            if let Some(res) = source_map
-                                .node_expr(expr)
-                                .and_then(|it| infer_result.assoc_resolutions_for_expr(it.into()))
-                            {
-                                return Exact(NavigationTarget::from_impl_item(db, res));
-                            }
-                        }
+    // General case, a path or a local:
+    if let Some(path) = name_ref.syntax().ancestors().find_map(ast::Path::cast) {
+        if let Some(resolved) = analyzer.resolve_path(db, path) {
+            match resolved {
+                hir::PathResolution::Def(def) => return Exact(NavigationTarget::from_def(db, def)),
+                hir::PathResolution::LocalBinding(pat) => {
+                    if let Some(pat) = analyzer.pat_syntax(db, pat) {
+                        let nav = NavigationTarget::from_pat(db, file_id, pat);
+                        return Exact(nav);
                     }
+                }
+                hir::PathResolution::GenericParam(..) => {
+                    // FIXME: go to the generic param def
+                }
+                hir::PathResolution::SelfType(impl_block) => {
+                    let ty = impl_block.target_ty(db);
 
-                    // Resolve associated item for path patterns
-                    if let Some(path_pat) =
-                        name_ref.syntax().ancestors().find_map(ast::PathPat::cast)
-                    {
-                        let infer_result = function.infer(db);
-                        let source_map = function.body_source_map(db);
-
-                        let pat: &ast::Pat = path_pat.into();
-
-                        if let Some(res) = source_map
-                            .node_pat(pat)
-                            .and_then(|it| infer_result.assoc_resolutions_for_pat(it.into()))
-                        {
-                            return Exact(NavigationTarget::from_impl_item(db, res));
-                        }
+                    if let Some((def_id, _)) = ty.as_adt() {
+                        return Exact(NavigationTarget::from_adt_def(db, def_id));
                     }
                 }
+                hir::PathResolution::AssocItem(assoc) => {
+                    return Exact(NavigationTarget::from_impl_item(db, assoc))
+                }
             }
         }
     }
 
-    // If that fails try the index based approach.
+    // Fallback index based approach:
     let navs = crate::symbol_index::index_resolve(db, name_ref)
         .into_iter()
         .map(NavigationTarget::from_symbol)
diff --git a/crates/ra_ide_api/src/hover.rs b/crates/ra_ide_api/src/hover.rs
index 3a8c93b99..ec167a196 100644
--- a/crates/ra_ide_api/src/hover.rs
+++ b/crates/ra_ide_api/src/hover.rs
@@ -132,17 +132,15 @@ pub(crate) fn type_of(db: &RootDatabase, frange: FileRange) -> Option<String> {
         .ancestors()
         .take_while(|it| it.range() == leaf_node.range())
         .find(|&it| ast::Expr::cast(it).is_some() || ast::Pat::cast(it).is_some())?;
-    let parent_fn = node.ancestors().find_map(ast::FnDef::cast)?;
-    let function = hir::source_binder::function_from_source(db, frange.file_id, parent_fn)?;
-    let infer = function.infer(db);
-    let source_map = function.body_source_map(db);
-    if let Some(expr) = ast::Expr::cast(node).and_then(|e| source_map.node_expr(e)) {
-        Some(infer[expr].display(db).to_string())
-    } else if let Some(pat) = ast::Pat::cast(node).and_then(|p| source_map.node_pat(p)) {
-        Some(infer[pat].display(db).to_string())
+    let analyzer = hir::SourceAnalyser::new(db, frange.file_id, node);
+    let ty = if let Some(ty) = ast::Expr::cast(node).and_then(|e| analyzer.type_of(db, e)) {
+        ty
+    } else if let Some(ty) = ast::Pat::cast(node).and_then(|p| analyzer.type_of_pat(db, p)) {
+        ty
     } else {
-        None
-    }
+        return None;
+    };
+    Some(ty.display(db).to_string())
 }
 
 #[cfg(test)]