Numeric read seems too strict

Ivan Lazar Miljenovic ivan.miljenovic at gmail.com
Sun Oct 2 04:07:39 UTC 2016


On 2 October 2016 at 14:34, David Feuer <david.feuer at gmail.com> wrote:
> Instead of scanning first (in lexing) to find the end of the number and then
> scanning the string again to calculate the number, start to calculate once
> the first digit appears.

As in multiply the current sum by 10 before adding each new digit?

>
>
> On Oct 1, 2016 10:07 PM, "wren romano" <winterkoninkje at gmail.com> wrote:
>>
>> On Mon, Sep 12, 2016 at 11:03 AM, David Feuer <david.feuer at gmail.com>
>> wrote:
>> > By the way, I believe we should be able to read numbers more efficiently
>> > by
>> > parsing them directly instead of lexing first. We have to deal with
>> > parentheses, white space, and signs uniformly for all number types. Then
>> > specialized foldl'-style code *should* be able to parse integral and
>> > fractional numbers faster than any lex-first scheme.
>>
>> I follow the part about parentheses and negations, but I'm not sure I
>> get the rest of what you mean. E.g., I'm not sure how any parser could
>> be faster than what bytestring-lexing does for Fractional and Integral
>> types (ignoring the unoptimized hex and octal functions). What am I
>> missing?
>>
>> --
>> Live well,
>> ~wren
>
>
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-- 
Ivan Lazar Miljenovic
Ivan.Miljenovic at gmail.com
http://IvanMiljenovic.wordpress.com


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