rust/crates/assists/src/utils.rs

325 lines
9.7 KiB
Rust

//! Assorted functions shared by several assists.
pub(crate) mod insert_use;
pub(crate) mod import_assets;
use std::ops;
use hir::{Crate, Enum, Module, ScopeDef, Semantics, Trait};
use ide_db::RootDatabase;
use itertools::Itertools;
use syntax::{
ast::{self, make, ArgListOwner},
AstNode, Direction,
SyntaxKind::*,
SyntaxNode, TextSize, T,
};
use crate::assist_config::SnippetCap;
pub use insert_use::MergeBehaviour;
pub(crate) use insert_use::{insert_use, ImportScope};
pub fn mod_path_to_ast(path: &hir::ModPath) -> ast::Path {
let mut segments = Vec::new();
let mut is_abs = false;
match path.kind {
hir::PathKind::Plain => {}
hir::PathKind::Super(0) => segments.push(make::path_segment_self()),
hir::PathKind::Super(n) => segments.extend((0..n).map(|_| make::path_segment_super())),
hir::PathKind::DollarCrate(_) | hir::PathKind::Crate => {
segments.push(make::path_segment_crate())
}
hir::PathKind::Abs => is_abs = true,
}
segments.extend(
path.segments
.iter()
.map(|segment| make::path_segment(make::name_ref(&segment.to_string()))),
);
make::path_from_segments(segments, is_abs)
}
pub(crate) fn unwrap_trivial_block(block: ast::BlockExpr) -> ast::Expr {
extract_trivial_expression(&block)
.filter(|expr| !expr.syntax().text().contains_char('\n'))
.unwrap_or_else(|| block.into())
}
pub fn extract_trivial_expression(block: &ast::BlockExpr) -> Option<ast::Expr> {
let has_anything_else = |thing: &SyntaxNode| -> bool {
let mut non_trivial_children =
block.syntax().children_with_tokens().filter(|it| match it.kind() {
WHITESPACE | T!['{'] | T!['}'] => false,
_ => it.as_node() != Some(thing),
});
non_trivial_children.next().is_some()
};
if let Some(expr) = block.expr() {
if has_anything_else(expr.syntax()) {
return None;
}
return Some(expr);
}
// Unwrap `{ continue; }`
let (stmt,) = block.statements().next_tuple()?;
if let ast::Stmt::ExprStmt(expr_stmt) = stmt {
if has_anything_else(expr_stmt.syntax()) {
return None;
}
let expr = expr_stmt.expr()?;
match expr.syntax().kind() {
CONTINUE_EXPR | BREAK_EXPR | RETURN_EXPR => return Some(expr),
_ => (),
}
}
None
}
#[derive(Clone, Copy, Debug)]
pub(crate) enum Cursor<'a> {
Replace(&'a SyntaxNode),
Before(&'a SyntaxNode),
}
impl<'a> Cursor<'a> {
fn node(self) -> &'a SyntaxNode {
match self {
Cursor::Replace(node) | Cursor::Before(node) => node,
}
}
}
pub(crate) fn render_snippet(_cap: SnippetCap, node: &SyntaxNode, cursor: Cursor) -> String {
assert!(cursor.node().ancestors().any(|it| it == *node));
let range = cursor.node().text_range() - node.text_range().start();
let range: ops::Range<usize> = range.into();
let mut placeholder = cursor.node().to_string();
escape(&mut placeholder);
let tab_stop = match cursor {
Cursor::Replace(placeholder) => format!("${{0:{}}}", placeholder),
Cursor::Before(placeholder) => format!("$0{}", placeholder),
};
let mut buf = node.to_string();
buf.replace_range(range, &tab_stop);
return buf;
fn escape(buf: &mut String) {
stdx::replace(buf, '{', r"\{");
stdx::replace(buf, '}', r"\}");
stdx::replace(buf, '$', r"\$");
}
}
pub(crate) fn vis_offset(node: &SyntaxNode) -> TextSize {
node.children_with_tokens()
.find(|it| !matches!(it.kind(), WHITESPACE | COMMENT | ATTR))
.map(|it| it.text_range().start())
.unwrap_or_else(|| node.text_range().start())
}
pub(crate) fn invert_boolean_expression(expr: ast::Expr) -> ast::Expr {
if let Some(expr) = invert_special_case(&expr) {
return expr;
}
make::expr_prefix(T![!], expr)
}
fn invert_special_case(expr: &ast::Expr) -> Option<ast::Expr> {
match expr {
ast::Expr::BinExpr(bin) => match bin.op_kind()? {
ast::BinOp::NegatedEqualityTest => bin.replace_op(T![==]).map(|it| it.into()),
ast::BinOp::EqualityTest => bin.replace_op(T![!=]).map(|it| it.into()),
_ => None,
},
ast::Expr::MethodCallExpr(mce) => {
let receiver = mce.receiver()?;
let method = mce.name_ref()?;
let arg_list = mce.arg_list()?;
let method = match method.text().as_str() {
"is_some" => "is_none",
"is_none" => "is_some",
"is_ok" => "is_err",
"is_err" => "is_ok",
_ => return None,
};
Some(make::expr_method_call(receiver, method, arg_list))
}
ast::Expr::PrefixExpr(pe) if pe.op_kind()? == ast::PrefixOp::Not => pe.expr(),
// FIXME:
// ast::Expr::Literal(true | false )
_ => None,
}
}
/// Helps with finding well-know things inside the standard library. This is
/// somewhat similar to the known paths infra inside hir, but it different; We
/// want to make sure that IDE specific paths don't become interesting inside
/// the compiler itself as well.
pub struct FamousDefs<'a, 'b>(pub &'a Semantics<'b, RootDatabase>, pub Option<Crate>);
#[allow(non_snake_case)]
impl FamousDefs<'_, '_> {
pub const FIXTURE: &'static str = r#"//- /libcore.rs crate:core
pub mod convert {
pub trait From<T> {
fn from(t: T) -> Self;
}
}
pub mod iter {
pub use self::traits::{collect::IntoIterator, iterator::Iterator};
mod traits {
pub(crate) mod iterator {
use crate::option::Option;
pub trait Iterator {
type Item;
fn next(&mut self) -> Option<Self::Item>;
fn by_ref(&mut self) -> &mut Self {
self
}
fn take(self, n: usize) -> crate::iter::Take<Self> {
crate::iter::Take { inner: self }
}
}
impl<I: Iterator> Iterator for &mut I {
type Item = I::Item;
fn next(&mut self) -> Option<I::Item> {
(**self).next()
}
}
}
pub(crate) mod collect {
pub trait IntoIterator {
type Item;
}
}
}
pub use self::sources::*;
pub(crate) mod sources {
use super::Iterator;
use crate::option::Option::{self, *};
pub struct Repeat<A> {
element: A,
}
pub fn repeat<T>(elt: T) -> Repeat<T> {
Repeat { element: elt }
}
impl<A> Iterator for Repeat<A> {
type Item = A;
fn next(&mut self) -> Option<A> {
None
}
}
}
pub use self::adapters::*;
pub(crate) mod adapters {
use super::Iterator;
use crate::option::Option::{self, *};
pub struct Take<I> { pub(crate) inner: I }
impl<I> Iterator for Take<I> where I: Iterator {
type Item = <I as Iterator>::Item;
fn next(&mut self) -> Option<<I as Iterator>::Item> {
None
}
}
}
}
pub mod option {
pub enum Option<T> { None, Some(T)}
}
pub mod prelude {
pub use crate::{convert::From, iter::{IntoIterator, Iterator}, option::Option::{self, *}};
}
#[prelude_import]
pub use prelude::*;
"#;
pub fn core(&self) -> Option<Crate> {
self.find_crate("core")
}
pub(crate) fn core_convert_From(&self) -> Option<Trait> {
self.find_trait("core:convert:From")
}
pub(crate) fn core_option_Option(&self) -> Option<Enum> {
self.find_enum("core:option:Option")
}
pub fn core_iter_Iterator(&self) -> Option<Trait> {
self.find_trait("core:iter:traits:iterator:Iterator")
}
pub fn core_iter(&self) -> Option<Module> {
self.find_module("core:iter")
}
fn find_trait(&self, path: &str) -> Option<Trait> {
match self.find_def(path)? {
hir::ScopeDef::ModuleDef(hir::ModuleDef::Trait(it)) => Some(it),
_ => None,
}
}
fn find_enum(&self, path: &str) -> Option<Enum> {
match self.find_def(path)? {
hir::ScopeDef::ModuleDef(hir::ModuleDef::Adt(hir::Adt::Enum(it))) => Some(it),
_ => None,
}
}
fn find_module(&self, path: &str) -> Option<Module> {
match self.find_def(path)? {
hir::ScopeDef::ModuleDef(hir::ModuleDef::Module(it)) => Some(it),
_ => None,
}
}
fn find_crate(&self, name: &str) -> Option<Crate> {
let krate = self.1?;
let db = self.0.db;
let res =
krate.dependencies(db).into_iter().find(|dep| dep.name.to_string() == name)?.krate;
Some(res)
}
fn find_def(&self, path: &str) -> Option<ScopeDef> {
let db = self.0.db;
let mut path = path.split(':');
let trait_ = path.next_back()?;
let std_crate = path.next()?;
let std_crate = self.find_crate(std_crate)?;
let mut module = std_crate.root_module(db);
for segment in path {
module = module.children(db).find_map(|child| {
let name = child.name(db)?;
if name.to_string() == segment {
Some(child)
} else {
None
}
})?;
}
let def =
module.scope(db, None).into_iter().find(|(name, _def)| name.to_string() == trait_)?.1;
Some(def)
}
}
pub(crate) fn next_prev() -> impl Iterator<Item = Direction> {
[Direction::Next, Direction::Prev].iter().copied()
}