value_types + struct+types = decimal
rubys at intertwingly.net
Sat Oct 16 14:34:40 PDT 2010
I'm pleased to see value_types discussed again:
It is my belief that value_types and struct_types are sufficient
to build a pure ECMAScript implementation of Decimal. Such an approach
would solve a number of problems:
(1) Ubiquity. Making Decimals a required feature was controversial
within the committee. Anything less would hamper adoption. Making the
implementation in ECMAScript and having that implementation only depend
on value_types and struct_types, then the implementation effectively
becomes as ubiquitous as those two features.
(2) Format. A number of committee members objected to 754R as a format.
Those that wish to pursue their own formats would be welcome do to so.
The only key requirement that this is not known to satisfy is:
(3) Performance. While we were not expecting hardware level
performance, something approximating C-level performance was the goal.
Mitigating that is:
(3a) ECMAScript implementations have improved dramatically since this
was last evaluated. The expectation is that this trend will continue.
And given the expected use case for struct_types, it is especially
likely that that feature will be implemented with performance in mind.
(3b) Not all users have the same performance requirements.
(3c) A stable implementation written in C with a liberal license
continues to be available. This will always be an option for
enlightened browser vendors with an interest in performance.
Given those mitigating factors, I am quite willing to proceed with the
above approach, and would strongly encourage the committee to consider
adopting the value_types proposal, and to not make any design decision
which would preclude struct_types from being considered as a value_type.
- Sam Ruby
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