562146 - Add native 'while' operator in javascript Generator expressions (feature request)

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, defect)

Description

[Dimitri Saltanov]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 (.NET CLR 3.5.30729)
Build Identifier: 

Consider this:

let source = (value for(value in I) while(value != stop));

versus the verbose klutz minimally required for the same effect in 1.8:

let source = (value for(value in I) if(value != stop || function(){throw StopIteration}()));

While native Generator expressions (GE's) in JS1.8 provide additional expressive power over other iteration techniques and, potentially, more resource economy over array comprehensions, I feel that both of these benefits are somewhat compromised by the absence of a built-in, concise control syntax allowing GE's to abort. I think that a native while operator proposed above would be a valuable addition to GE's.


Reproducible: Always

Steps to Reproduce:
Nada. Feature not available (yet - hopefully).

Comment 1

[André Bargull [:anba]]

JS1.8 generator comprehension were removed in bug 1220564, resolving as Won't Fix.