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use ra_db::SourceDatabase;
use ra_syntax::{
AstNode, SyntaxNode, TreeArc, ast,
algo::{find_covering_node, find_node_at_offset, find_leaf_at_offset, visit::{visitor, Visitor}},
};
use crate::{db::RootDatabase, RangeInfo, FilePosition, FileRange, NavigationTarget};
pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeInfo<String>> {
let file = db.parse(position.file_id);
let mut res = Vec::new();
let mut range = None;
if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(file.syntax(), position.offset) {
use crate::goto_definition::{ReferenceResult::*, reference_definition};
let ref_result = reference_definition(db, position.file_id, name_ref);
match ref_result {
Exact(nav) => res.extend(doc_text_for(db, nav)),
Approximate(navs) => {
let mut msg = String::from("Failed to exactly resolve the symbol. This is probably because rust_analyzer does not yet support glob imports or traits.");
if !navs.is_empty() {
msg.push_str(" \nThese items were found instead:");
}
res.push(msg);
for nav in navs {
res.extend(doc_text_for(db, nav))
}
}
}
if !res.is_empty() {
range = Some(name_ref.syntax().range())
}
}
if range.is_none() {
let node = find_leaf_at_offset(file.syntax(), position.offset).find_map(|leaf| {
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));
range = Some(node.range());
};
let range = range?;
if res.is_empty() {
return None;
}
let res = RangeInfo::new(range, res.join("\n\n---\n"));
Some(res)
}
pub(crate) fn type_of(db: &RootDatabase, frange: FileRange) -> Option<String> {
let file = db.parse(frange.file_id);
let syntax = file.syntax();
let leaf_node = find_covering_node(syntax, frange.range);
// if we picked identifier, expand to pattern/expression
let node = leaf_node
.ancestors()
.take_while(|it| it.range() == leaf_node.range())
.find(|&it| ast::Expr::cast(it).is_some() || ast::Pat::cast(it).is_some())
.unwrap_or(leaf_node);
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)) {
Some(infer[expr].to_string())
} else if let Some(pat) = ast::Pat::cast(node).and_then(|p| syntax_mapping.node_pat(p)) {
Some(infer[pat].to_string())
} else {
None
}
}
// FIXME: this should not really use navigation target. Rather, approximatelly
// resovled 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```"),
(None, Some(docs)) => Some(docs),
_ => None,
}
}
impl NavigationTarget {
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)
}
fn docs(&self, db: &RootDatabase) -> Option<String> {
let node = self.node(db)?;
fn doc_comments<N: ast::DocCommentsOwner>(node: &N) -> Option<String> {
let comments = node.doc_comment_text();
if comments.is_empty() {
None
} else {
Some(comments)
}
}
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::TypeDef>)
.visit(doc_comments::<ast::ConstDef>)
.visit(doc_comments::<ast::StaticDef>)
.accept(&node)?
}
/// Get a description of this node.
///
/// e.g. `struct Name`, `enum Name`, `fn Name`
fn description(&self, db: &RootDatabase) -> Option<String> {
// TODO: After type inference is done, add type information to improve the output
let node = self.node(db)?;
fn visit_node<T>(node: &T, label: &str) -> Option<String>
where
T: ast::NameOwner + ast::VisibilityOwner,
{
let mut string = node
.visibility()
.map(|v| format!("{} ", v.syntax().text()))
.unwrap_or_default();
string.push_str(label);
node.name()?.syntax().text().push_to(&mut string);
Some(string)
}
visitor()
.visit(|node: &ast::FnDef| visit_node(node, "fn "))
.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::TypeDef| visit_node(node, "type "))
.visit(|node: &ast::ConstDef| visit_node(node, "const "))
.visit(|node: &ast::StaticDef| visit_node(node, "static "))
.accept(&node)?
}
}
#[cfg(test)]
mod tests {
use ra_syntax::TextRange;
use crate::mock_analysis::{single_file_with_position, single_file_with_range};
#[test]
fn hover_shows_type_of_an_expression() {
let (analysis, position) = single_file_with_position(
"
pub fn foo() -> u32 { 1 }
fn main() {
let foo_test = foo()<|>;
}
",
);
let hover = analysis.hover(position).unwrap().unwrap();
assert_eq!(hover.range, TextRange::from_to(95.into(), 100.into()));
assert_eq!(hover.info, "u32");
}
#[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, "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, "i32");
}
#[test]
fn test_type_of_for_function() {
let (analysis, range) = single_file_with_range(
"
pub fn foo() -> u32 { 1 };
fn main() {
let foo_test = <|>foo()<|>;
}
",
);
let type_name = analysis.type_of(range).unwrap().unwrap();
assert_eq!("u32", &type_name);
}
// FIXME: improve type_of to make this work
#[test]
fn test_type_of_for_expr_1() {
let (analysis, range) = single_file_with_range(
"
fn main() {
let foo = <|>1 + foo_test<|>;
}
",
);
let type_name = analysis.type_of(range).unwrap().unwrap();
assert_eq!("[unknown]", &type_name);
}
#[test]
fn test_type_of_for_expr_2() {
let (analysis, range) = single_file_with_range(
"
fn main() {
let foo: usize = 1;
let bar = <|>1 + foo<|>;
}
",
);
let type_name = analysis.type_of(range).unwrap().unwrap();
assert_eq!("usize", &type_name);
}
}
|
