Promote expr block.
@@ -546,19 +546,21 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
Stmt::Import(expr, _, _) => optimize_expr(expr, state),
// { block }
Stmt::Block(statements, pos) => {
- let block = mem::take(statements);
- *stmt = match optimize_stmt_block(block, state, preserve_result, true, false) {
- statements if statements.is_empty() => {
+ let mut block =
+ optimize_stmt_block(mem::take(statements), state, preserve_result, true, false);
+
+ match block.as_mut_slice() {
+ [] => {
state.set_dirty();
- Stmt::Noop(*pos)
+ *stmt = Stmt::Noop(*pos);
}
// Only one statement - promote
- mut statements if statements.len() == 1 => {
+ [s] => {
state.set_dirty();
- statements.pop().unwrap()
+ *stmt = mem::take(s);
+ }
+ _ => *stmt = Stmt::Block(block, *pos),
}
- statements => Stmt::Block(statements, *pos),
- };
}
// try { pure try_block } catch ( var ) { catch_block } -> try_block
Stmt::TryCatch(x, _, _) if x.0.statements.iter().all(Stmt::is_pure) => {
@@ -609,18 +611,16 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
match expr {
// {}
Expr::Stmt(x) if x.statements.is_empty() => { state.set_dirty(); *expr = Expr::Unit(x.pos) }
- // { Stmt(Expr) }
- Expr::Stmt(x) if x.statements.len() == 1 && x.statements[0].is_pure() && matches!(x.statements[0], Stmt::Expr(_)) =>
- {
- state.set_dirty();
- if let Stmt::Expr(e) = mem::take(&mut x.statements[0]) {
- *expr = e;
- } else {
- unreachable!();
+ // { stmt; ... } - do not count promotion as dirty because it gets turned back into an array
+ Expr::Stmt(x) => {
+ x.statements = optimize_stmt_block(mem::take(&mut x.statements).into_vec(), state, true, true, false).into();
+
+ // { Stmt(Expr) } - promote
+ match x.statements.as_mut() {
+ [ Stmt::Expr(e) ] => { state.set_dirty(); *expr = mem::take(e); }
+ _ => ()
}
}
- // { stmt; ... } - do not count promotion as dirty because it gets turned back into an array
- Expr::Stmt(x) => x.statements = optimize_stmt_block(mem::take(&mut x.statements).into_vec(), state, true, true, false).into(),
// lhs.rhs
#[cfg(not(feature = "no_object"))]
Expr::Dot(x, _) => match (&mut x.lhs, &mut x.rhs) {
