Re: [boost] [filesystem] Function name changes

From: David Abrahams (dave_at_[hidden])
Date: 2008-07-03 21:13:07

Michael Marcin wrote:
> David Abrahams wrote:
>> Bjørn Roald wrote:
>>> Beman Dawes wrote:
>>>>
>>>> * Change branch()    to parent_path()
>>>> * Change leaf()      to child()
>>>> * Change basename()  to child_prefix()
>>>> * Change extension() to child_extension()
>>>>
>>>> At first glance, those names seem reasonable clear and self-consistent.
>>>>
>>>> What's your take on that set?
>>> I am not sure this is any good.  Considder the path "../../a/b" and the
>>> meaning of parent and child.
>>>
>>> The only sensible parent is in the middle and we don't even know it's
>>> name.  Children are at both ends the implicit "." or "b".
>>
>> The parent of '../../a/b' is '../../a'
>> The parent of '../../a' is '../..'
>> The parent of '../..' is probably '../../..'
>>
>> If Beman intended '..' to be the result of the final transformation
>> above, then we should be using something like pop() to describe it.
>>
>>
> 
> Doesn't leaf serve 2 functions? If the path points to a directory it
> returns most derived directory 

It does not return a directory.  We don't have a type that can represent
a directory.  We only have paths and strings.

> (to make a bad analogy to class
> hierarchy). If the path points to a file it returns the filename.

No.  In either case it returns the name of the thing that the path
points to.

> It seems to me that this duality makes it difficult to choose a
> meaningful name in the domain of file systems.
> 
> Personally I think I like
> 
> parent()     - if this is a path to a subdirectory or a file returns a
> path one level above directory() otherwise returns *this

IIUC, this function is not supposed to touch the filesystem.  It's
supposed to be a pure path manipulation.

> directory()  - if this is a path to a file returns a path to the
> directory that contains the file otherwise returns *this

ditto

> filename()   - if this is a path to a file returns a string containing
> the filename otherwise returns an empty string

ditto

> basename()   - if this is a path to a file returns a string containing
> the filename without its extension otherwise returns an empty string

ditto

> extension()  - if this is a path to a file returns a string contains the
> filename without its basename otherwise returns an empty string

:)  you get the idea.

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com