//! Functionality for generating trivial constructors
use hir::StructKind;
use span::Edition;
use syntax::{
ToSmolStr,
ast::{Expr, Path, make, syntax_factory::SyntaxFactory},
};
/// given a type return the trivial constructor (if one exists)
pub fn use_trivial_constructor(
db: &crate::RootDatabase,
path: Path,
ty: &hir::Type<'_>,
edition: Edition,
) -> Option<Expr> {
match ty.as_adt() {
Some(hir::Adt::Enum(x)) => {
if let &[variant] = &*x.variants(db)
&& variant.kind(db) == hir::StructKind::Unit
{
let path = make::path_qualified(
path,
make::path_segment(make::name_ref(
&variant.name(db).display_no_db(edition).to_smolstr(),
)),
);
return Some(make::expr_path(path));
}
}
Some(hir::Adt::Struct(x)) if x.kind(db) == StructKind::Unit => {
return Some(make::expr_path(path));
}
_ => {}
}
None
}
pub fn use_trivial_constructor_with_factory(
make: &SyntaxFactory,
db: &crate::RootDatabase,
path: Path,
ty: &hir::Type<'_>,
edition: Edition,
) -> Option<Expr> {
match ty.as_adt() {
Some(hir::Adt::Enum(x)) => {
if let &[variant] = &*x.variants(db)
&& variant.kind(db) == hir::StructKind::Unit
{
let path = make.path_qualified(
path,
make.path_segment(
make.name_ref(&variant.name(db).display_no_db(edition).to_smolstr()),
),
);
return Some(make.expr_path(path));
}
}
Some(hir::Adt::Struct(x)) if x.kind(db) == StructKind::Unit => {
return Some(make.expr_path(path));
}
_ => {}
}
None
}