mdebray/tvl-depot
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

chore(tvix/eval): delete "useless parenthesis" warning/optimisation

Browse source 
Two main reasons:

1. Traversing the structure to do this optimisation is
   actually *slower* than not optimising it.

2. There are literally hundreds of thousands of incidences of this in
   nixpkgs, and with some of the weird code there some of
   these (functionally) useless parens are actually required for
   readability reasons.

Change-Id: I1044b1c5f9fe20df4b6085851fc3b191277c65dc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7917
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
This commit is contained in:
Vincent Ambo 2023-01-23 20:28:53 +03:00 committed by clbot
parent d2f1a290a4
commit 9ecf668452
2 changed files with 0 additions and 30 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
tvix/eval/src/compiler/optimiser.rs
View file

@ -9,7 +9,6 @@ use ast::Expr;
pub(super) fn optimise_expr(c: &mut Compiler, slot: LocalIdx, expr: ast::Expr) -> ast::Expr {
match expr {
Expr::BinOp(_) => optimise_bin_op(c, slot, expr),
Expr::Paren(_) => optimise_paren(c, expr),
_ => expr.to_owned(),
}
}
@ -124,28 +123,3 @@ fn optimise_bin_op(c: &mut Compiler, slot: LocalIdx, expr: ast::Expr) -> ast::Ex
expr
}
/// Detect useless parenthesis around primitive expressions.
fn optimise_paren(c: &mut Compiler, expr: ast::Expr) -> ast::Expr {
if let Expr::Paren(inner) = &expr {
let inner = inner.expr().unwrap();
if let Expr::Paren(_) = &inner {
c.emit_warning(&expr, WarningKind::UselessParens);
return optimise_paren(c, inner);
}
if let Expr::Literal(_)
| Expr::Str(_)
| Expr::Select(_)
| Expr::List(_)
| Expr::AttrSet(_)
| Expr::Ident(_) = &inner
{
c.emit_warning(&expr, WarningKind::UselessParens);
return inner;
}
}
expr
}

4
tvix/eval/src/warnings.rs
View file

@ -17,7 +17,6 @@ pub enum WarningKind {
DeadCode,
EmptyInherit,
EmptyLet,
UselessParens,
/// Tvix internal warning for features triggered by users that are
/// not actually implemented yet, but do not cause runtime failures.
@ -101,8 +100,6 @@ impl EvalWarning {
WarningKind::EmptyLet => "this `let`-expression contains no bindings".to_string(),
WarningKind::UselessParens => "these parenthesis can be removed".to_string(),
WarningKind::NotImplemented(what) => {
format!("feature not yet implemented in tvix: {}", what)
}
@ -123,7 +120,6 @@ impl EvalWarning {
WarningKind::DeadCode => "W008",
WarningKind::EmptyInherit => "W009",
WarningKind::EmptyLet => "W010",
WarningKind::UselessParens => "W011",
WarningKind::NotImplemented(_) => "W999",
}