internal: more reasonable grammar for blocks

Consider these expples

        { 92 }
  async { 92 }
    'a: { 92 }
   #[a] { 92 }

Previously the tree for them were

  BLOCK_EXPR
    { ... }

  EFFECT_EXPR
    async
    BLOCK_EXPR
      { ... }

  EFFECT_EXPR
    'a:
    BLOCK_EXPR
      { ... }

  BLOCK_EXPR
    #[a]
    { ... }

As you see, it gets progressively worse :) The last two items are
especially odd. The last one even violates the balanced curleys
invariant we have (#10357) The new approach is to say that the stuff in
`{}` is stmt_list, and the block is stmt_list + optional modifiers

  BLOCK_EXPR
    STMT_LIST
      { ... }

  BLOCK_EXPR
    async
    STMT_LIST
      { ... }

  BLOCK_EXPR
    'a:
    STMT_LIST
      { ... }

  BLOCK_EXPR
    #[a]
    STMT_LIST
      { ... }
This commit is contained in:
Aleksey Kladov 2021-09-26 12:12:57 +03:00
parent c51a3c78cf
commit 2bf81922f7
233 changed files with 11762 additions and 11343 deletions

View file

@ -86,8 +86,8 @@ pub(super) fn try_expr(
ast::Fn(fn_) => sema.to_def(&fn_)?.ret_type(sema.db),
ast::Item(__) => return None,
ast::ClosureExpr(closure) => sema.type_of_expr(&closure.body()?)?.original,
ast::EffectExpr(effect) => if matches!(effect.effect(), ast::Effect::Async(_) | ast::Effect::Try(_)| ast::Effect::Const(_)) {
sema.type_of_expr(&effect.block_expr()?.into())?.original
ast::BlockExpr(block_expr) => if matches!(block_expr.modifier(), Some(ast::BlockModifier::Async(_) | ast::BlockModifier::Try(_)| ast::BlockModifier::Const(_))) {
sema.type_of_expr(&block_expr.into())?.original
} else {
continue;
},