Re: [boost] [http] Design ideas for a request router

On 22/03/2016 09:49, Vinícius dos Santos Oliveira wrote:

2016-03-20 19:06 GMT-03:00 Uisleandro :

...

4. This implementation considers "%i", "%d" and "%f" as the same, which means that they will be placed in group,

I don't like the use of printf-style formatters.

For one, you have to learn these letter and they're useless anyway (C++ has the necessary machinery to detect the used type).

Another reason to avoid them is the easy-to-misuse/lack-of-planned-extensibility/unsafety they tend to acquire as they evolve. Besides the type, you might need formatting options and using printf this is text you put between the '%' sign and the type letter. Expressions start to get long and confuse and it's hard to tell when they end. It's way easier to use something like Python's {} where you know where are the beginning/end points (even if you have several formatting options).

Another issue is localization, but it may be less important in this domain. Printf style formatting doesn't allow you to reorder arguments, which is very important in localization where different languages may use the arguments in different order.

http://www.boost.org/doc/libs/1_60_0/libs/format/doc/format.html This encourages a clean syntax by default, although it does have printf-based underpinnings as well.

...

"%%" (which means all the characters from the current position) are placed separately;

This sort of thing is usually treated as an escape for an actual % in the resulting string; it seems like a bad idea to give this a different meaning. It also seems like a bad idea to use % in general in the context of URL strings, as this already has a defined (hex escape) meaning. While granted it would be rare to use unusual characters that require escapes in API-style endpoint addresses, there's no particular reason that someone should be prevented from doing so due to overloaded meanings.