Re: [boost] [string_algo] trim_left should be trim_head

From: Gennaro Prota (gennaro_prota_at_[hidden])
Date: 2006-07-03 12:17:35

On Sun, 02 Jul 2006 23:52:55 +0200, Pavol Droba <droba_at_[hidden]>
wrote:

>Well, it depends on what you define as 'de-facto' standard.
>I think that both names are equaly good.
>
>[snip]
>
>- Probably not very serious, but simple google comparison give following
>results:
>"trimhead OR trimhead" : 1,510 results

Just for precision sake: "trim_head OR trimhead"; yes, that yields
1510 results, of which many have nothing to do with programming.

> [snip]
>
>I don't have much time to look elsewhere, feel free to supply
>counterexamples.
>
>Before considering your proposal, I would really need to see
>better argument then your personal opinion, since changing a name
>of a function that is already in use for some time is quite serious
>issue.

It is basically all about conventions. One has to specify that "left"
means "head" and right means "tail" (and specify what head and tail
are).

To illustrate with an example, consider a sentence such as "the
cartesian diagram of x = constant is a vertical straight line". Such a
statement carries a ton of inaccuracies:

a) the cartesian diagram concerns functions, and "x = constant" is not
a function: it represents a function

b) "vertical straight line" means nothing per se: it should be "line
parallel to the y axis"

c) bullet b is erroneous too if you only define parallelism between
straight lines: an "axis" is not a line, because to be fully specified
it needs an ordering between points (it can be defined as a pair (l,
R) where l is a straight line and R an appropriate order relation on
it). Thus to use the idiom "parallel to the axis" you should specify
that "a straight line L is said to be parallel to an axis A if and
only if it is parallel to the first component of A" (to which you can
give a specific name, for instance "the support of the axis A").

That said, I prefer the trim_head and trim_tail names, even if less
popular (and popularity could be a criterion which would lead all of
us to use pretty much different names than we use in C++ :))

__
-----------------------------------------
   Gennaro Prota, C++ developer for hire
       resume:  available on request
------------------------------------------