rust-analyzer/crates/ra_ide/src/imports_locator.rs

//! This module contains an import search funcionality that is provided to the ra_assists module.
//! Later, this should be moved away to a separate crate that is accessible from the ra_assists module.

use crate::{
    db::RootDatabase,
    references::{classify_name, classify_name_ref, NameDefinition, NameKind},
    symbol_index::{self, FileSymbol},
    Query,
};
use ast::NameRef;
use hir::{db::HirDatabase, InFile, ModPath, Module, SourceBinder};
use itertools::Itertools;
use ra_assists::ImportsLocator;
use ra_prof::profile;
use ra_syntax::{ast, AstNode, SyntaxKind::NAME};

pub(crate) struct ImportsLocatorIde<'a> {
    source_binder: SourceBinder<'a, RootDatabase>,
}

impl<'a> ImportsLocatorIde<'a> {
    pub(crate) fn new(db: &'a RootDatabase) -> Self {
        Self { source_binder: SourceBinder::new(db) }
    }

    fn search_for_imports(
        &mut self,
        name_to_import: &ast::NameRef,
        module_with_name_to_import: Module,
    ) -> Vec<ModPath> {
        let _p = profile("search_for_imports");
        let db = self.source_binder.db;
        let name_to_import = name_to_import.text();

        let project_results = {
            let mut query = Query::new(name_to_import.to_string());
            query.exact();
            query.limit(40);
            symbol_index::world_symbols(db, query)
        };
        let lib_results = {
            let mut query = Query::new(name_to_import.to_string());
            query.libs();
            query.exact();
            query.limit(40);
            symbol_index::world_symbols(db, query)
        };

        project_results
            .into_iter()
            .chain(lib_results.into_iter())
            .filter_map(|import_candidate| self.get_name_definition(db, &import_candidate))
            .filter_map(|name_definition_to_import| {
                if let NameKind::Def(module_def) = name_definition_to_import.kind {
                    module_with_name_to_import.find_use_path(db, module_def)
                } else {
                    None
                }
            })
            .filter(|use_path| !use_path.segments.is_empty())
            .unique()
            .take(20)
            .collect()
    }

    fn get_name_definition(
        &mut self,
        db: &impl HirDatabase,
        import_candidate: &FileSymbol,
    ) -> Option<NameDefinition> {
        let _p = profile("get_name_definition");
        let file_id = import_candidate.file_id.into();
        let candidate_node = import_candidate.ptr.to_node(&db.parse_or_expand(file_id)?);
        let candidate_name_node = if candidate_node.kind() != NAME {
            candidate_node.children().find(|it| it.kind() == NAME)?
        } else {
            candidate_node
        };
        classify_name(
            &mut self.source_binder,
            hir::InFile { file_id, value: &ast::Name::cast(candidate_name_node)? },
        )
    }
}

impl<'a> ImportsLocator for ImportsLocatorIde<'a> {
    fn find_imports(
        &mut self,
        name_to_import: InFile<&NameRef>,
        module_with_name_to_import: Module,
    ) -> Option<Vec<ModPath>> {
        if classify_name_ref(&mut self.source_binder, name_to_import).is_none() {
            Some(self.search_for_imports(name_to_import.value, module_with_name_to_import))
        } else {
            None
        }
    }
}