7 files changed, 136 insertions, 31 deletions

diff --git a/crates/ra_ide_api/src/change.rs b/crates/ra_ide_api/src/change.rs
index 3f041f9c3..0c90ed5b5 100644
--- a/crates/ra_ide_api/src/change.rs
+++ b/crates/ra_ide_api/src/change.rs
@@ -223,8 +223,7 @@ impl RootDatabase {
         self.query(hir::db::FileItemsQuery).sweep(sweep);
         self.query(hir::db::FileItemQuery).sweep(sweep);
 
-        self.query(hir::db::LowerModuleQuery).sweep(sweep);
-        self.query(hir::db::LowerModuleSourceMapQuery).sweep(sweep);
-        self.query(hir::db::BodySyntaxMappingQuery).sweep(sweep);
+        self.query(hir::db::LowerModuleWithSourceMapQuery).sweep(sweep);
+        self.query(hir::db::BodyWithSourceMapQuery).sweep(sweep);
     }
 }
diff --git a/crates/ra_ide_api/src/completion/complete_dot.rs b/crates/ra_ide_api/src/completion/complete_dot.rs
index d5ad2e79f..94c66be31 100644
--- a/crates/ra_ide_api/src/completion/complete_dot.rs
+++ b/crates/ra_ide_api/src/completion/complete_dot.rs
@@ -9,8 +9,8 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
         _ => return,
     };
     let infer_result = function.infer(ctx.db);
-    let syntax_mapping = function.body_syntax_mapping(ctx.db);
-    let expr = match syntax_mapping.node_expr(receiver) {
+    let source_map = function.body_source_map(ctx.db);
+    let expr = match source_map.node_expr(receiver) {
         Some(expr) => expr,
         None => return,
     };
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 afb092f59..6bef9624e 100644
--- a/crates/ra_ide_api/src/completion/complete_struct_literal.rs
+++ b/crates/ra_ide_api/src/completion/complete_struct_literal.rs
@@ -9,8 +9,8 @@ pub(super) fn complete_struct_literal(acc: &mut Completions, ctx: &CompletionCon
         _ => return,
     };
     let infer_result = function.infer(ctx.db);
-    let syntax_mapping = function.body_syntax_mapping(ctx.db);
-    let expr = match syntax_mapping.node_expr(struct_lit.into()) {
+    let source_map = function.body_source_map(ctx.db);
+    let expr = match source_map.node_expr(struct_lit.into()) {
         Some(expr) => expr,
         None => return,
     };
diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide_api/src/goto_definition.rs
index 6fa430754..9ec179593 100644
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide_api/src/goto_definition.rs
@@ -54,10 +54,10 @@ pub(crate) fn reference_definition(
         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 syntax_mapping = function.body_syntax_mapping(db);
+            let source_map = function.body_source_map(db);
             let expr = ast::Expr::cast(method_call.syntax()).unwrap();
             if let Some(func) =
-                syntax_mapping.node_expr(expr).and_then(|it| infer_result.method_resolution(it))
+                source_map.node_expr(expr).and_then(|it| infer_result.method_resolution(it))
             {
                 return Exact(NavigationTarget::from_function(db, func));
             };
@@ -66,10 +66,10 @@ pub(crate) fn reference_definition(
         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 syntax_mapping = function.body_syntax_mapping(db);
+            let source_map = function.body_source_map(db);
             let expr = ast::Expr::cast(field_expr.syntax()).unwrap();
             if let Some(field) =
-                syntax_mapping.node_expr(expr).and_then(|it| infer_result.field_resolution(it))
+                source_map.node_expr(expr).and_then(|it| infer_result.field_resolution(it))
             {
                 return Exact(NavigationTarget::from_field(db, field));
             };
@@ -80,11 +80,11 @@ pub(crate) fn reference_definition(
             tested_by!(goto_definition_works_for_named_fields);
 
             let infer_result = function.infer(db);
-            let syntax_mapping = function.body_syntax_mapping(db);
+            let source_map = function.body_source_map(db);
 
             let struct_lit = field_expr.syntax().ancestors().find_map(ast::StructLit::cast);
 
-            if let Some(expr) = struct_lit.and_then(|lit| syntax_mapping.node_expr(lit.into())) {
+            if let Some(expr) = struct_lit.and_then(|lit| source_map.node_expr(lit.into())) {
                 let ty = infer_result[expr].clone();
                 if let hir::Ty::Adt { def_id, .. } = ty {
                     if let hir::AdtDef::Struct(s) = def_id {
@@ -109,9 +109,8 @@ pub(crate) fn reference_definition(
             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 syntax_mapping = body.syntax_mapping(db);
-                let ptr =
-                    syntax_mapping.pat_syntax(pat).expect("pattern not found in syntax mapping");
+                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 nav = NavigationTarget::from_scope_entry(file_id, name, ptr);
diff --git a/crates/ra_ide_api/src/hover.rs b/crates/ra_ide_api/src/hover.rs
index 1a1853df3..8ec60090d 100644
--- a/crates/ra_ide_api/src/hover.rs
+++ b/crates/ra_ide_api/src/hover.rs
@@ -107,7 +107,7 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
             leaf.ancestors().find(|n| ast::Expr::cast(*n).is_some() || ast::Pat::cast(*n).is_some())
         })?;
         let frange = FileRange { file_id: position.file_id, range: node.range() };
-        res.extend(type_of(db, frange).map(Into::into));
+        res.extend(type_of(db, frange).map(rust_code_markup));
         range = Some(node.range());
     }
 
@@ -132,22 +132,37 @@ pub(crate) fn type_of(db: &RootDatabase, frange: FileRange) -> Option<String> {
     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 syntax_mapping = function.body_syntax_mapping(db);
-    if let Some(expr) = ast::Expr::cast(node).and_then(|e| syntax_mapping.node_expr(e)) {
+    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].to_string())
-    } else if let Some(pat) = ast::Pat::cast(node).and_then(|p| syntax_mapping.node_pat(p)) {
+    } else if let Some(pat) = ast::Pat::cast(node).and_then(|p| source_map.node_pat(p)) {
         Some(infer[pat].to_string())
     } else {
         None
     }
 }
 
+fn rust_code_markup<CODE: AsRef<str>>(val: CODE) -> String {
+    rust_code_markup_with_doc::<_, &str>(val, None)
+}
+
+fn rust_code_markup_with_doc<CODE, DOC>(val: CODE, doc: Option<DOC>) -> String
+where
+    CODE: AsRef<str>,
+    DOC: AsRef<str>,
+{
+    if let Some(doc) = doc {
+        format!("```rust\n{}\n```\n\n{}", val.as_ref(), doc.as_ref())
+    } else {
+        format!("```rust\n{}\n```", val.as_ref())
+    }
+}
+
 // FIXME: this should not really use navigation target. Rather, approximately
 // resolved symbol should return a `DefId`.
 fn doc_text_for(db: &RootDatabase, nav: NavigationTarget) -> Option<String> {
     match (nav.description(db), nav.docs(db)) {
-        (Some(desc), Some(docs)) => Some("```rust\n".to_string() + &*desc + "\n```\n\n" + &*docs),
-        (Some(desc), None) => Some("```rust\n".to_string() + &*desc + "\n```"),
+        (Some(desc), docs) => Some(rust_code_markup_with_doc(desc, docs)),
         (None, Some(docs)) => Some(docs),
         _ => None,
     }
@@ -238,6 +253,10 @@ mod tests {
         s.trim_start_matches("```rust\n").trim_end_matches("\n```")
     }
 
+    fn trim_markup_opt(s: Option<&str>) -> Option<&str> {
+        s.map(trim_markup)
+    }
+
     fn check_hover_result(fixture: &str, expected: &[&str]) {
         let (analysis, position) = analysis_and_position(fixture);
         let hover = analysis.hover(position).unwrap().unwrap();
@@ -264,7 +283,7 @@ mod tests {
         );
         let hover = analysis.hover(position).unwrap().unwrap();
         assert_eq!(hover.range, TextRange::from_to(95.into(), 100.into()));
-        assert_eq!(hover.info.first(), Some("u32"));
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("u32"));
     }
 
     #[test]
@@ -410,21 +429,21 @@ mod tests {
         );
         let hover = analysis.hover(position).unwrap().unwrap();
         // not the nicest way to show it currently
-        assert_eq!(hover.info.first(), Some("Some<i32>(T) -> Option<T>"));
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("Some<i32>(T) -> Option<T>"));
     }
 
     #[test]
     fn hover_for_local_variable() {
         let (analysis, position) = single_file_with_position("fn func(foo: i32) { fo<|>o; }");
         let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(hover.info.first(), Some("i32"));
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("i32"));
     }
 
     #[test]
     fn hover_for_local_variable_pat() {
         let (analysis, position) = single_file_with_position("fn func(fo<|>o: i32) {}");
         let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(hover.info.first(), Some("i32"));
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("i32"));
     }
 
     #[test]
@@ -455,7 +474,7 @@ mod tests {
         );
 
         let type_name = analysis.type_of(range).unwrap().unwrap();
-        assert_eq!("[unknown]", &type_name);
+        assert_eq!("{unknown}", &type_name);
     }
 
     #[test]
@@ -491,6 +510,6 @@ mod tests {
             ",
         );
         let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(hover.info.first(), Some("Thing"));
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("Thing"));
     }
 }
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index 6546d0644..b8a4adbce 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -32,13 +32,14 @@ mod references;
 mod impls;
 mod assists;
 mod diagnostics;
+mod syntax_tree;
 
 #[cfg(test)]
 mod marks;
 
 use std::sync::Arc;
 
-use ra_syntax::{SourceFile, TreeArc, TextRange, TextUnit, AstNode};
+use ra_syntax::{SourceFile, TreeArc, TextRange, TextUnit};
 use ra_text_edit::TextEdit;
 use ra_db::{
     SourceDatabase, CheckCanceled,
@@ -245,8 +246,8 @@ impl Analysis {
 
     /// Returns a syntax tree represented as `String`, for debug purposes.
     // FIXME: use a better name here.
-    pub fn syntax_tree(&self, file_id: FileId) -> String {
-        self.db.parse(file_id).syntax().debug_dump()
+    pub fn syntax_tree(&self, file_id: FileId, text_range: Option<TextRange>) -> String {
+        syntax_tree::syntax_tree(&self.db, file_id, text_range)
     }
 
     /// Returns an edit to remove all newlines in the range, cleaning up minor
diff --git a/crates/ra_ide_api/src/syntax_tree.rs b/crates/ra_ide_api/src/syntax_tree.rs
new file mode 100644
index 000000000..bbe9222b4
--- /dev/null
+++ b/crates/ra_ide_api/src/syntax_tree.rs
@@ -0,0 +1,87 @@
+use ra_db::SourceDatabase;

+use crate::db::RootDatabase;

+use ra_syntax::{

+    SourceFile, SyntaxNode, TextRange, AstNode,

+    algo::{self, visit::{visitor, Visitor}}, ast::{self, AstToken}

+};

+

+pub use ra_db::FileId;

+

+pub(crate) fn syntax_tree(

+    db: &RootDatabase,

+    file_id: FileId,

+    text_range: Option<TextRange>,

+) -> String {

+    if let Some(text_range) = text_range {

+        let file = db.parse(file_id);

+        let node = algo::find_covering_node(file.syntax(), text_range);

+

+        if let Some(tree) = syntax_tree_for_string(node, text_range) {

+            return tree;

+        }

+

+        node.debug_dump()

+    } else {

+        db.parse(file_id).syntax().debug_dump()

+    }

+}

+

+/// Attempts parsing the selected contents of a string literal

+/// as rust syntax and returns its syntax tree

+fn syntax_tree_for_string(node: &SyntaxNode, text_range: TextRange) -> Option<String> {

+    // When the range is inside a string

+    // we'll attempt parsing it as rust syntax

+    // to provide the syntax tree of the contents of the string

+    visitor()

+        .visit(|node: &ast::String| syntax_tree_for_token(node, text_range))

+        .visit(|node: &ast::RawString| syntax_tree_for_token(node, text_range))

+        .accept(node)?

+}

+

+fn syntax_tree_for_token<T: AstToken>(node: &T, text_range: TextRange) -> Option<String> {

+    // Range of the full node

+    let node_range = node.syntax().range();

+    let text = node.text().to_string();

+

+    // We start at some point inside the node

+    // Either we have selected the whole string

+    // or our selection is inside it

+    let start = text_range.start() - node_range.start();

+

+    // how many characters we have selected

+    let len = text_range.len().to_usize();

+

+    let node_len = node_range.len().to_usize();

+

+    let start = start.to_usize();

+

+    // We want to cap our length

+    let len = len.min(node_len);

+

+    // Ensure our slice is inside the actual string

+    let end = if start + len < text.len() { start + len } else { text.len() - start };

+

+    let text = &text[start..end];

+

+    // Remove possible extra string quotes from the start

+    // and the end of the string

+    let text = text

+        .trim_start_matches('r')

+        .trim_start_matches('#')

+        .trim_start_matches('"')

+        .trim_end_matches('#')

+        .trim_end_matches('"')

+        .trim()

+        // Remove custom markers

+        .replace("<|>", "");

+

+    let parsed = SourceFile::parse(&text);

+

+    // If the "file" parsed without errors,

+    // return its syntax

+    if parsed.errors().is_empty() {

+        return Some(parsed.syntax().debug_dump());

+    }

+

+    None

+}