Slide 17
Slide 17 text
Problematic grammars
Javascript has curious grammars. If you start writing parser of javascript,
you'll see ECMA262 grammars and you’ll find Cover* grammars.
CoverParenthesizedExpressionAndArrowParameterList
This long name grammar was created for arrow function and parenthesized
expression like below.
(a, b, c) => {...}
(a, b, c);
Arrow function and parenthesized expression can’t distinct until find “=>”
glyph.
So ecma262 solve this problem by treat this two grammar as same grammar
tree that has different meaning.