waldemar at google.com
Mon May 23 14:09:57 PDT 2011
On 05/21/11 23:53, Brendan Eich wrote:
> That's accurate. But I discounted arrow functions because to be usable, to have the syntax you show above, requires GLR parsing (if bottom up; top-down may be easier, haven't proven it yet).
GLR parsing would be wild in ECMAScript due to the fact that the lexer is dependent on the parser's current state. A GLR parser is working on a quantum superposition of multiple states in parallel, so if it encounters a / then some of the superposed states may direct the lexer to interpret it as a division symbol while others direct it to start scanning a regular expression. So now you need a quantum entanglement of lexers corresponding to the superposed parser states the GLR parser is considering. Semicolon insertion would also be be forced into quantum entanglement with the superposed parser states.
Do we really want to go there?
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