1 files changed, 329 insertions, 0 deletions

diff --git a/crates/ra_ide_api/src/display/navigation_target.rs b/crates/ra_ide_api/src/display/navigation_target.rs
new file mode 100644
index 000000000..3c518faf5
--- /dev/null
+++ b/crates/ra_ide_api/src/display/navigation_target.rs
@@ -0,0 +1,329 @@
+use ra_db::{FileId, SourceDatabase};
+use ra_syntax::{
+    SyntaxNode, SyntaxNodePtr, AstNode, SmolStr, TextRange, TreeArc,
+    SyntaxKind::{self, NAME},
+    ast::{self, NameOwner, VisibilityOwner, TypeAscriptionOwner},
+    algo::visit::{visitor, Visitor},
+};
+use hir::{ModuleSource, FieldSource, Name, ImplItem};
+
+use crate::{FileSymbol, db::RootDatabase};
+
+/// `NavigationTarget` represents and element in the editor's UI which you can
+/// click on to navigate to a particular piece of code.
+///
+/// Typically, a `NavigationTarget` corresponds to some element in the source
+/// code, like a function or a struct, but this is not strictly required.
+#[derive(Debug, Clone)]
+pub struct NavigationTarget {
+    file_id: FileId,
+    name: SmolStr,
+    kind: SyntaxKind,
+    full_range: TextRange,
+    focus_range: Option<TextRange>,
+    container_name: Option<SmolStr>,
+}
+
+impl NavigationTarget {
+    /// When `focus_range` is specified, returns it. otherwise
+    /// returns `full_range`
+    pub fn range(&self) -> TextRange {
+        self.focus_range.unwrap_or(self.full_range)
+    }
+
+    pub fn name(&self) -> &SmolStr {
+        &self.name
+    }
+
+    pub fn container_name(&self) -> Option<&SmolStr> {
+        self.container_name.as_ref()
+    }
+
+    pub fn kind(&self) -> SyntaxKind {
+        self.kind
+    }
+
+    pub fn file_id(&self) -> FileId {
+        self.file_id
+    }
+
+    pub fn full_range(&self) -> TextRange {
+        self.full_range
+    }
+
+    /// A "most interesting" range withing the `full_range`.
+    ///
+    /// Typically, `full_range` is the whole syntax node,
+    /// including doc comments, and `focus_range` is the range of the identifier.
+    pub fn focus_range(&self) -> Option<TextRange> {
+        self.focus_range
+    }
+
+    pub(crate) fn from_bind_pat(file_id: FileId, pat: &ast::BindPat) -> NavigationTarget {
+        NavigationTarget::from_named(file_id, pat)
+    }
+
+    pub(crate) fn from_symbol(symbol: FileSymbol) -> NavigationTarget {
+        NavigationTarget {
+            file_id: symbol.file_id,
+            name: symbol.name.clone(),
+            kind: symbol.ptr.kind(),
+            full_range: symbol.ptr.range(),
+            focus_range: symbol.name_range,
+            container_name: symbol.container_name.clone(),
+        }
+    }
+
+    pub(crate) fn from_scope_entry(
+        file_id: FileId,
+        name: Name,
+        ptr: SyntaxNodePtr,
+    ) -> NavigationTarget {
+        NavigationTarget {
+            file_id,
+            name: name.to_string().into(),
+            full_range: ptr.range(),
+            focus_range: None,
+            kind: NAME,
+            container_name: None,
+        }
+    }
+
+    pub(crate) fn from_module(db: &RootDatabase, module: hir::Module) -> NavigationTarget {
+        let (file_id, source) = module.definition_source(db);
+        let file_id = file_id.as_original_file();
+        let name = module.name(db).map(|it| it.to_string().into()).unwrap_or_default();
+        match source {
+            ModuleSource::SourceFile(node) => {
+                NavigationTarget::from_syntax(file_id, name, None, node.syntax())
+            }
+            ModuleSource::Module(node) => {
+                NavigationTarget::from_syntax(file_id, name, None, node.syntax())
+            }
+        }
+    }
+
+    pub(crate) fn from_module_to_decl(db: &RootDatabase, module: hir::Module) -> NavigationTarget {
+        let name = module.name(db).map(|it| it.to_string().into()).unwrap_or_default();
+        if let Some((file_id, source)) = module.declaration_source(db) {
+            let file_id = file_id.as_original_file();
+            return NavigationTarget::from_syntax(file_id, name, None, source.syntax());
+        }
+        NavigationTarget::from_module(db, module)
+    }
+
+    pub(crate) fn from_function(db: &RootDatabase, func: hir::Function) -> NavigationTarget {
+        let (file_id, fn_def) = func.source(db);
+        NavigationTarget::from_named(file_id.original_file(db), &*fn_def)
+    }
+
+    pub(crate) fn from_field(db: &RootDatabase, field: hir::StructField) -> NavigationTarget {
+        let (file_id, field) = field.source(db);
+        let file_id = file_id.original_file(db);
+        match field {
+            FieldSource::Named(it) => NavigationTarget::from_named(file_id, &*it),
+            FieldSource::Pos(it) => {
+                NavigationTarget::from_syntax(file_id, "".into(), None, it.syntax())
+            }
+        }
+    }
+
+    pub(crate) fn from_adt_def(db: &RootDatabase, adt_def: hir::AdtDef) -> NavigationTarget {
+        match adt_def {
+            hir::AdtDef::Struct(s) => {
+                let (file_id, node) = s.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            hir::AdtDef::Enum(s) => {
+                let (file_id, node) = s.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+        }
+    }
+
+    pub(crate) fn from_def(db: &RootDatabase, module_def: hir::ModuleDef) -> NavigationTarget {
+        match module_def {
+            hir::ModuleDef::Module(module) => NavigationTarget::from_module(db, module),
+            hir::ModuleDef::Function(func) => NavigationTarget::from_function(db, func),
+            hir::ModuleDef::Struct(s) => {
+                let (file_id, node) = s.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            hir::ModuleDef::Const(s) => {
+                let (file_id, node) = s.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            hir::ModuleDef::Static(s) => {
+                let (file_id, node) = s.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            hir::ModuleDef::Enum(e) => {
+                let (file_id, node) = e.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            hir::ModuleDef::EnumVariant(var) => {
+                let (file_id, node) = var.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            hir::ModuleDef::Trait(e) => {
+                let (file_id, node) = e.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            hir::ModuleDef::TypeAlias(e) => {
+                let (file_id, node) = e.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+        }
+    }
+
+    pub(crate) fn from_impl_block(
+        db: &RootDatabase,
+        impl_block: hir::ImplBlock,
+    ) -> NavigationTarget {
+        let (file_id, node) = impl_block.source(db);
+        NavigationTarget::from_syntax(
+            file_id.as_original_file(),
+            "impl".into(),
+            None,
+            node.syntax(),
+        )
+    }
+
+    pub(crate) fn from_impl_item(db: &RootDatabase, impl_item: hir::ImplItem) -> NavigationTarget {
+        match impl_item {
+            ImplItem::Method(f) => NavigationTarget::from_function(db, f),
+            ImplItem::Const(c) => {
+                let (file_id, node) = c.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            ImplItem::TypeAlias(a) => {
+                let (file_id, node) = a.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+        }
+    }
+
+    #[cfg(test)]
+    pub(crate) fn assert_match(&self, expected: &str) {
+        let actual = self.debug_render();
+        test_utils::assert_eq_text!(expected.trim(), actual.trim(),);
+    }
+
+    #[cfg(test)]
+    pub(crate) fn debug_render(&self) -> String {
+        let mut buf = format!(
+            "{} {:?} {:?} {:?}",
+            self.name(),
+            self.kind(),
+            self.file_id(),
+            self.full_range()
+        );
+        if let Some(focus_range) = self.focus_range() {
+            buf.push_str(&format!(" {:?}", focus_range))
+        }
+        if let Some(container_name) = self.container_name() {
+            buf.push_str(&format!(" {}", container_name))
+        }
+        buf
+    }
+
+    /// Allows `NavigationTarget` to be created from a `NameOwner`
+    pub(crate) fn from_named(file_id: FileId, node: &impl ast::NameOwner) -> NavigationTarget {
+        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())
+    }
+
+    fn from_syntax(
+        file_id: FileId,
+        name: SmolStr,
+        focus_range: Option<TextRange>,
+        node: &SyntaxNode,
+    ) -> NavigationTarget {
+        NavigationTarget {
+            file_id,
+            name,
+            kind: node.kind(),
+            full_range: node.range(),
+            focus_range,
+            // ptr: Some(LocalSyntaxPtr::new(node)),
+            container_name: None,
+        }
+    }
+
+    pub(crate) fn node(&self, db: &RootDatabase) -> Option<TreeArc<SyntaxNode>> {
+        let source_file = db.parse(self.file_id());
+        let source_file = source_file.syntax();
+        let node = source_file
+            .descendants()
+            .find(|node| node.kind() == self.kind() && node.range() == self.full_range())?
+            .to_owned();
+        Some(node)
+    }
+
+    pub(crate) fn docs(&self, db: &RootDatabase) -> Option<String> {
+        let node = self.node(db)?;
+        fn doc_comments<N: ast::DocCommentsOwner>(node: &N) -> Option<String> {
+            node.doc_comment_text()
+        }
+
+        visitor()
+            .visit(doc_comments::<ast::FnDef>)
+            .visit(doc_comments::<ast::StructDef>)
+            .visit(doc_comments::<ast::EnumDef>)
+            .visit(doc_comments::<ast::TraitDef>)
+            .visit(doc_comments::<ast::Module>)
+            .visit(doc_comments::<ast::TypeAliasDef>)
+            .visit(doc_comments::<ast::ConstDef>)
+            .visit(doc_comments::<ast::StaticDef>)
+            .visit(doc_comments::<ast::NamedFieldDef>)
+            .visit(doc_comments::<ast::EnumVariant>)
+            .accept(&node)?
+    }
+
+    /// Get a description of this node.
+    ///
+    /// e.g. `struct Name`, `enum Name`, `fn Name`
+    pub(crate) fn description(&self, db: &RootDatabase) -> Option<String> {
+        // FIXME: After type inference is done, add type information to improve the output
+        let node = self.node(db)?;
+
+        fn visit_ascribed_node<T>(node: &T, prefix: &str) -> Option<String>
+        where
+            T: NameOwner + VisibilityOwner + TypeAscriptionOwner,
+        {
+            let mut string = visit_node(node, prefix)?;
+
+            if let Some(type_ref) = node.ascribed_type() {
+                string.push_str(": ");
+                type_ref.syntax().text().push_to(&mut string);
+            }
+
+            Some(string)
+        }
+
+        fn visit_node<T>(node: &T, label: &str) -> Option<String>
+        where
+            T: NameOwner + VisibilityOwner,
+        {
+            let mut string =
+                node.visibility().map(|v| format!("{} ", v.syntax().text())).unwrap_or_default();
+            string.push_str(label);
+            string.push_str(node.name()?.text().as_str());
+            Some(string)
+        }
+
+        visitor()
+            .visit(|node: &ast::FnDef| Some(crate::display::function_label(node)))
+            .visit(|node: &ast::StructDef| visit_node(node, "struct "))
+            .visit(|node: &ast::EnumDef| visit_node(node, "enum "))
+            .visit(|node: &ast::TraitDef| visit_node(node, "trait "))
+            .visit(|node: &ast::Module| visit_node(node, "mod "))
+            .visit(|node: &ast::TypeAliasDef| visit_node(node, "type "))
+            .visit(|node: &ast::ConstDef| visit_ascribed_node(node, "const "))
+            .visit(|node: &ast::StaticDef| visit_ascribed_node(node, "static "))
+            .visit(|node: &ast::NamedFieldDef| visit_ascribed_node(node, ""))
+            .visit(|node: &ast::EnumVariant| Some(node.name()?.text().to_string()))
+            .accept(&node)?
+    }
+}