1 files changed, 411 insertions, 0 deletions

diff --git a/crates/ra_ide/src/display/navigation_target.rs b/crates/ra_ide/src/display/navigation_target.rs
new file mode 100644
index 000000000..6ac60722b
--- /dev/null
+++ b/crates/ra_ide/src/display/navigation_target.rs
@@ -0,0 +1,411 @@
+//! FIXME: write short doc here
+
+use hir::{AssocItem, Either, FieldSource, HasSource, ModuleSource, Source};
+use ra_db::{FileId, SourceDatabase};
+use ra_syntax::{
+    ast::{self, DocCommentsOwner, NameOwner},
+    match_ast, AstNode, SmolStr,
+    SyntaxKind::{self, BIND_PAT},
+    TextRange,
+};
+
+use crate::{db::RootDatabase, expand::original_range, FileSymbol};
+
+use super::short_label::ShortLabel;
+
+/// `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>,
+    description: Option<String>,
+    docs: Option<String>,
+}
+
+pub(crate) trait ToNav {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget;
+}
+
+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
+    }
+
+    pub fn docs(&self) -> Option<&str> {
+        self.docs.as_ref().map(String::as_str)
+    }
+
+    pub fn description(&self) -> Option<&str> {
+        self.description.as_ref().map(String::as_str)
+    }
+
+    /// 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_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(src) = module.declaration_source(db) {
+            let frange = original_range(db, src.as_ref().map(|it| it.syntax()));
+            return NavigationTarget::from_syntax(
+                frange.file_id,
+                name,
+                None,
+                frange.range,
+                src.value.syntax().kind(),
+                src.value.doc_comment_text(),
+                src.value.short_label(),
+            );
+        }
+        module.to_nav(db)
+    }
+
+    pub(crate) fn from_def(
+        db: &RootDatabase,
+        module_def: hir::ModuleDef,
+    ) -> Option<NavigationTarget> {
+        let nav = match module_def {
+            hir::ModuleDef::Module(module) => module.to_nav(db),
+            hir::ModuleDef::Function(it) => it.to_nav(db),
+            hir::ModuleDef::Adt(it) => it.to_nav(db),
+            hir::ModuleDef::Const(it) => it.to_nav(db),
+            hir::ModuleDef::Static(it) => it.to_nav(db),
+            hir::ModuleDef::EnumVariant(it) => it.to_nav(db),
+            hir::ModuleDef::Trait(it) => it.to_nav(db),
+            hir::ModuleDef::TypeAlias(it) => it.to_nav(db),
+            hir::ModuleDef::BuiltinType(..) => {
+                return None;
+            }
+        };
+        Some(nav)
+    }
+
+    #[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(
+        db: &RootDatabase,
+        node: Source<&dyn ast::NameOwner>,
+        docs: Option<String>,
+        description: Option<String>,
+    ) -> NavigationTarget {
+        //FIXME: use `_` instead of empty string
+        let name = node.value.name().map(|it| it.text().clone()).unwrap_or_default();
+        let focus_range =
+            node.value.name().map(|it| original_range(db, node.with_value(it.syntax())).range);
+        let frange = original_range(db, node.map(|it| it.syntax()));
+
+        NavigationTarget::from_syntax(
+            frange.file_id,
+            name,
+            focus_range,
+            frange.range,
+            node.value.syntax().kind(),
+            docs,
+            description,
+        )
+    }
+
+    fn from_syntax(
+        file_id: FileId,
+        name: SmolStr,
+        focus_range: Option<TextRange>,
+        full_range: TextRange,
+        kind: SyntaxKind,
+        docs: Option<String>,
+        description: Option<String>,
+    ) -> NavigationTarget {
+        NavigationTarget {
+            file_id,
+            name,
+            kind,
+            full_range,
+            focus_range,
+            container_name: None,
+            description,
+            docs,
+        }
+    }
+}
+
+impl ToNav for FileSymbol {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        NavigationTarget {
+            file_id: self.file_id,
+            name: self.name.clone(),
+            kind: self.ptr.kind(),
+            full_range: self.ptr.range(),
+            focus_range: self.name_range,
+            container_name: self.container_name.clone(),
+            description: description_from_symbol(db, self),
+            docs: docs_from_symbol(db, self),
+        }
+    }
+}
+
+pub(crate) trait ToNavFromAst {}
+impl ToNavFromAst for hir::Function {}
+impl ToNavFromAst for hir::Const {}
+impl ToNavFromAst for hir::Static {}
+impl ToNavFromAst for hir::Struct {}
+impl ToNavFromAst for hir::Enum {}
+impl ToNavFromAst for hir::EnumVariant {}
+impl ToNavFromAst for hir::Union {}
+impl ToNavFromAst for hir::TypeAlias {}
+impl ToNavFromAst for hir::Trait {}
+
+impl<D> ToNav for D
+where
+    D: HasSource + ToNavFromAst + Copy,
+    D::Ast: ast::DocCommentsOwner + ast::NameOwner + ShortLabel,
+{
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        NavigationTarget::from_named(
+            db,
+            src.as_ref().map(|it| it as &dyn ast::NameOwner),
+            src.value.doc_comment_text(),
+            src.value.short_label(),
+        )
+    }
+}
+
+impl ToNav for hir::Module {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.definition_source(db);
+        let name = self.name(db).map(|it| it.to_string().into()).unwrap_or_default();
+        match &src.value {
+            ModuleSource::SourceFile(node) => {
+                let frange = original_range(db, src.with_value(node.syntax()));
+
+                NavigationTarget::from_syntax(
+                    frange.file_id,
+                    name,
+                    None,
+                    frange.range,
+                    node.syntax().kind(),
+                    None,
+                    None,
+                )
+            }
+            ModuleSource::Module(node) => {
+                let frange = original_range(db, src.with_value(node.syntax()));
+
+                NavigationTarget::from_syntax(
+                    frange.file_id,
+                    name,
+                    None,
+                    frange.range,
+                    node.syntax().kind(),
+                    node.doc_comment_text(),
+                    node.short_label(),
+                )
+            }
+        }
+    }
+}
+
+impl ToNav for hir::ImplBlock {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        let frange = original_range(db, src.as_ref().map(|it| it.syntax()));
+
+        NavigationTarget::from_syntax(
+            frange.file_id,
+            "impl".into(),
+            None,
+            frange.range,
+            src.value.syntax().kind(),
+            None,
+            None,
+        )
+    }
+}
+
+impl ToNav for hir::StructField {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+
+        match &src.value {
+            FieldSource::Named(it) => NavigationTarget::from_named(
+                db,
+                src.with_value(it),
+                it.doc_comment_text(),
+                it.short_label(),
+            ),
+            FieldSource::Pos(it) => {
+                let frange = original_range(db, src.with_value(it.syntax()));
+                NavigationTarget::from_syntax(
+                    frange.file_id,
+                    "".into(),
+                    None,
+                    frange.range,
+                    it.syntax().kind(),
+                    None,
+                    None,
+                )
+            }
+        }
+    }
+}
+
+impl ToNav for hir::MacroDef {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        log::debug!("nav target {:#?}", src.value.syntax());
+        NavigationTarget::from_named(
+            db,
+            src.as_ref().map(|it| it as &dyn ast::NameOwner),
+            src.value.doc_comment_text(),
+            None,
+        )
+    }
+}
+
+impl ToNav for hir::Adt {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        match self {
+            hir::Adt::Struct(it) => it.to_nav(db),
+            hir::Adt::Union(it) => it.to_nav(db),
+            hir::Adt::Enum(it) => it.to_nav(db),
+        }
+    }
+}
+
+impl ToNav for hir::AssocItem {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        match self {
+            AssocItem::Function(it) => it.to_nav(db),
+            AssocItem::Const(it) => it.to_nav(db),
+            AssocItem::TypeAlias(it) => it.to_nav(db),
+        }
+    }
+}
+
+impl ToNav for hir::Local {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        let (full_range, focus_range) = match src.value {
+            Either::A(it) => {
+                (it.syntax().text_range(), it.name().map(|it| it.syntax().text_range()))
+            }
+            Either::B(it) => (it.syntax().text_range(), Some(it.self_kw_token().text_range())),
+        };
+        let name = match self.name(db) {
+            Some(it) => it.to_string().into(),
+            None => "".into(),
+        };
+        NavigationTarget {
+            file_id: src.file_id.original_file(db),
+            name,
+            kind: BIND_PAT,
+            full_range,
+            focus_range,
+            container_name: None,
+            description: None,
+            docs: None,
+        }
+    }
+}
+
+pub(crate) fn docs_from_symbol(db: &RootDatabase, symbol: &FileSymbol) -> Option<String> {
+    let parse = db.parse(symbol.file_id);
+    let node = symbol.ptr.to_node(parse.tree().syntax());
+
+    match_ast! {
+        match node {
+            ast::FnDef(it) => { it.doc_comment_text() },
+            ast::StructDef(it) => { it.doc_comment_text() },
+            ast::EnumDef(it) => { it.doc_comment_text() },
+            ast::TraitDef(it) => { it.doc_comment_text() },
+            ast::Module(it) => { it.doc_comment_text() },
+            ast::TypeAliasDef(it) => { it.doc_comment_text() },
+            ast::ConstDef(it) => { it.doc_comment_text() },
+            ast::StaticDef(it) => { it.doc_comment_text() },
+            ast::RecordFieldDef(it) => { it.doc_comment_text() },
+            ast::EnumVariant(it) => { it.doc_comment_text() },
+            ast::MacroCall(it) => { it.doc_comment_text() },
+            _ => None,
+        }
+    }
+}
+
+/// Get a description of a symbol.
+///
+/// e.g. `struct Name`, `enum Name`, `fn Name`
+pub(crate) fn description_from_symbol(db: &RootDatabase, symbol: &FileSymbol) -> Option<String> {
+    let parse = db.parse(symbol.file_id);
+    let node = symbol.ptr.to_node(parse.tree().syntax());
+
+    match_ast! {
+        match node {
+            ast::FnDef(it) => { it.short_label() },
+            ast::StructDef(it) => { it.short_label() },
+            ast::EnumDef(it) => { it.short_label() },
+            ast::TraitDef(it) => { it.short_label() },
+            ast::Module(it) => { it.short_label() },
+            ast::TypeAliasDef(it) => { it.short_label() },
+            ast::ConstDef(it) => { it.short_label() },
+            ast::StaticDef(it) => { it.short_label() },
+            ast::RecordFieldDef(it) => { it.short_label() },
+            ast::EnumVariant(it) => { it.short_label() },
+            _ => None,
+        }
+    }
+}