1 //! When specifying SSR rule, you generally want to map one *kind* of thing to
2 //! the same kind of thing: path to path, expression to expression, type to
5 //! The problem is, while this *kind* is generally obvious to the human, the ide
6 //! needs to determine it somehow. We do this in a stupid way -- by pasting SSR
7 //! rule into different contexts and checking what works.
9 use parser::SyntaxKind;
10 use syntax::{ast, AstNode, SyntaxNode};
12 pub(crate) fn ty(s: &str) -> Result<SyntaxNode, ()> {
13 let template = "type T = {};";
14 let input = template.replace("{}", s);
15 let parse = syntax::SourceFile::parse(&input);
16 if !parse.errors().is_empty() {
19 let node = parse.tree().syntax().descendants().find_map(ast::Type::cast).ok_or(())?;
20 Ok(node.syntax().clone())
23 pub(crate) fn item(s: &str) -> Result<SyntaxNode, ()> {
25 let input = template.replace("{}", s);
26 let parse = syntax::SourceFile::parse(&input);
27 if !parse.errors().is_empty() {
30 let node = parse.tree().syntax().descendants().find_map(ast::Item::cast).ok_or(())?;
31 Ok(node.syntax().clone())