Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Normative: Treat IterationStatements uniformly in Annex B.3.5. #1393

Merged
merged 1 commit into from
Feb 7, 2019
Merged

Normative: Treat IterationStatements uniformly in Annex B.3.5. #1393

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 2 additions & 3 deletions spec.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -40800,17 +40800,16 @@ <h1>VariableStatements in Catch Blocks</h1>
It is a Syntax Error if any element of the BoundNames of |CatchParameter| also occurs in the LexicallyDeclaredNames of |Block|.
</li>
<li>
It is a Syntax Error if any element of the BoundNames of |CatchParameter| also occurs in the VarDeclaredNames of |Block| unless |CatchParameter| is <emu-grammar>CatchParameter : BindingIdentifier</emu-grammar> and that element is only bound by a |VariableStatement|, the |VariableDeclarationList| of a for statement, the |ForBinding| of a for-in statement, or the |BindingIdentifier| of a for-in statement.
It is a Syntax Error if any element of the BoundNames of |CatchParameter| also occurs in the VarDeclaredNames of |Block| unless |CatchParameter| is <emu-grammar>CatchParameter : BindingIdentifier</emu-grammar>.
</li>
</ul>
<emu-note>
<p>The |Block| of a |Catch| clause may contain `var` declarations that bind a name that is also bound by the |CatchParameter|. At runtime, such bindings are instantiated in the VariableDeclarationEnvironment. They do not shadow the same-named bindings introduced by the |CatchParameter| and hence the |Initializer| for such `var` declarations will assign to the corresponding catch parameter rather than the `var` binding. The relaxation of the normal static semantic rule does not apply to names only bound by for-of statements.</p>
<p>The |Block| of a |Catch| clause may contain `var` declarations that bind a name that is also bound by the |CatchParameter|. At runtime, such bindings are instantiated in the VariableDeclarationEnvironment. They do not shadow the same-named bindings introduced by the |CatchParameter| and hence the |Initializer| for such `var` declarations will assign to the corresponding catch parameter rather than the `var` binding.</p>
</emu-note>
<p>This modified behaviour also applies to `var` and `function` declarations introduced by direct eval calls contained within the |Block| of a |Catch| clause. This change is accomplished by modifying the algorithm of <emu-xref href="#sec-evaldeclarationinstantiation"></emu-xref> as follows:</p>
<p>Step 5.d.ii.2.a.i is replaced by:</p>
<emu-alg type="i">
1. If _thisEnvRec_ is not the Environment Record for a |Catch| clause, throw a *SyntaxError* exception.
1. If _name_ is bound by any syntactic form other than a |FunctionDeclaration|, a |VariableStatement|, the |VariableDeclarationList| of a for statement, the |ForBinding| of a for-in statement, or the |BindingIdentifier| of a for-in statement, throw a *SyntaxError* exception.
</emu-alg>
<p>Step 9.d.ii.4.b.i.i is replaced by:</p>
<emu-alg type="i">
Expand Down