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use ra_syntax::{SmolStr, ast, AstNode, TextRange};
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Path {
pub kind: PathKind,
pub segments: Vec<SmolStr>,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum PathKind {
Plain,
Self_,
Super,
Crate,
}
impl Path {
/// Calls `cb` with all paths, represented by this use item.
pub fn expand_use_item(item: ast::UseItem, mut cb: impl FnMut(Path, Option<TextRange>)) {
if let Some(tree) = item.use_tree() {
expand_use_tree(None, tree, &mut cb);
}
}
/// Converts an `ast::Path` to `Path`. Works with use trees.
pub fn from_ast(mut path: ast::Path) -> Option<Path> {
let mut kind = PathKind::Plain;
let mut segments = Vec::new();
loop {
let segment = path.segment()?;
match segment.kind()? {
ast::PathSegmentKind::Name(name) => segments.push(name.text()),
ast::PathSegmentKind::CrateKw => {
kind = PathKind::Crate;
break;
}
ast::PathSegmentKind::SelfKw => {
kind = PathKind::Self_;
break;
}
ast::PathSegmentKind::SuperKw => {
kind = PathKind::Super;
break;
}
}
path = match qualifier(path) {
Some(it) => it,
None => break,
};
}
segments.reverse();
return Some(Path { kind, segments });
fn qualifier(path: ast::Path) -> Option<ast::Path> {
if let Some(q) = path.qualifier() {
return Some(q);
}
// TODO: this bottom up traversal is not too precise.
// Should we handle do a top-down analysiss, recording results?
let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
let use_tree = use_tree_list.parent_use_tree();
use_tree.path()
}
}
/// `true` is this path is a single identifier, like `foo`
pub fn is_ident(&self) -> bool {
self.kind == PathKind::Plain && self.segments.len() == 1
}
}
fn expand_use_tree(
prefix: Option<Path>,
tree: ast::UseTree,
cb: &mut impl FnMut(Path, Option<TextRange>),
) {
if let Some(use_tree_list) = tree.use_tree_list() {
let prefix = match tree.path() {
None => prefix,
Some(path) => match convert_path(prefix, path) {
Some(it) => Some(it),
None => return, // TODO: report errors somewhere
},
};
for tree in use_tree_list.use_trees() {
expand_use_tree(prefix.clone(), tree, cb);
}
} else {
if let Some(ast_path) = tree.path() {
if let Some(path) = convert_path(prefix, ast_path) {
let range = if tree.has_star() {
None
} else {
let range = ast_path.segment().unwrap().syntax().range();
Some(range)
};
cb(path, range)
}
}
}
}
fn convert_path(prefix: Option<Path>, path: ast::Path) -> Option<Path> {
let prefix = if let Some(qual) = path.qualifier() {
Some(convert_path(prefix, qual)?)
} else {
None
};
let segment = path.segment()?;
let res = match segment.kind()? {
ast::PathSegmentKind::Name(name) => {
let mut res = prefix.unwrap_or_else(|| Path {
kind: PathKind::Plain,
segments: Vec::with_capacity(1),
});
res.segments.push(name.text());
res
}
ast::PathSegmentKind::CrateKw => {
if prefix.is_some() {
return None;
}
Path {
kind: PathKind::Crate,
segments: Vec::new(),
}
}
ast::PathSegmentKind::SelfKw => {
if prefix.is_some() {
return None;
}
Path {
kind: PathKind::Self_,
segments: Vec::new(),
}
}
ast::PathSegmentKind::SuperKw => {
if prefix.is_some() {
return None;
}
Path {
kind: PathKind::Super,
segments: Vec::new(),
}
}
};
Some(res)
}
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