April 01, 2011
At least on Windows, as far as I know, the casing of a file extension doesn't come into play. But when comparing extensions, you have to be careful to lowercase the result of `getExt()`, for example:

foreach (string name; dirEntries(curdir, SpanMode.shallow))
{
    if (name.isFile && name.getExt == "txt")
    {
        // do something
    }
}

If the extension is cased "tXt", the if block will not be entered. That's a silent bug in your code right there!

I think we could use a function in Phobos that returns true if an extension of a file matches any number of strings passed to it (a range). And an extra argument could be a flag (enum) or a boolean which can set the case sensitivity to true, but is false by default, e.g.:

bool hasExt(Range)(string fileName, Range exts, bool caseSensitive = false)
{
    static if (isSomeString!Range)
    {
        if (caseSensitive)
        {
            if (exts == fileName.getExt)
                return true;
        }
        else
        {
            if (exts.tolower == fileName.getExt.tolower)
                return true;
        }
    }
    else
    {
        foreach (ext; exts)
        {
            if (caseSensitive)
            {
                if (ext == fileName.getExt)
                    return true;
            }
            else
            {
                if (ext.tolower == fileName.getExt.tolower)
                    return true;
            }
        }
    }

    return false;
}

foreach (string name; dirEntries(curdir, SpanMode.shallow))
{
    if (name.isFile && name.hasExt(["ini", "conf"]))
    {
        // do something
    }
}

Yes, that is a horrible implementation, but I can't be bothered with trying to make it nice and simple right now, I'm in a rush. Sorry. :)

I often have to search for files that have a certain extension. Having to expand the code to the following becomes ugly real fast:

foreach (string name; dirEntries(curdir, SpanMode.shallow))
{
    if (name.isFile && name.hasExt.tolower == "ini" ||
                   name.hasExt.tolower == "conf"))
    {
        // do something
    }
}
April 01, 2011
On 4/1/11, Andrej Mitrovic <none@none.none> wrote:
> I often have to search for files that have a certain extension. Having to expand the code to the following becomes ugly real fast:
>
> foreach (string name; dirEntries(curdir, SpanMode.shallow))
> {
>     if (name.isFile && name.hasExt.tolower == "ini" ||
>                    name.hasExt.tolower == "conf"))
>     {
>         // do something
>     }
> }
>

Oops, that showcase was supposed to use `getExt`.
April 01, 2011
On 04/01/2011 11:03 PM, Andrej Mitrovic wrote:
> At least on Windows, as far as I know, the casing of a file extension doesn't come into play. But when comparing extensions, you have to be careful to lowercase the result of `getExt()`, for example:
>
> foreach (string name; dirEntries(curdir, SpanMode.shallow))
> {
>      if (name.isFile&&  name.getExt == "txt")
>      {
>          // do something
>      }
> }
>
> If the extension is cased "tXt", the if block will not be entered. That's a silent bug in your code right there!
>
> I think we could use a function in Phobos that returns true if an extension of a file matches any number of strings passed to it (a range). And an extra argument could be a flag (enum) or a boolean which can set the case sensitivity to true, but is false by default, e.g.:
>
> bool hasExt(Range)(string fileName, Range exts, bool caseSensitive = false)
> {
>      static if (isSomeString!Range)
>      {
>          if (caseSensitive)
>          {
>              if (exts == fileName.getExt)
>                  return true;
>          }
>          else
>          {
>              if (exts.tolower == fileName.getExt.tolower)
>                  return true;
>          }
>      }
>      else
>      {
>          foreach (ext; exts)
>          {
>              if (caseSensitive)
>              {
>                  if (ext == fileName.getExt)
>                      return true;
>              }
>              else
>              {
>                  if (ext.tolower == fileName.getExt.tolower)
>                      return true;
>              }
>          }
>      }
>
>      return false;
> }
>
> foreach (string name; dirEntries(curdir, SpanMode.shallow))
> {
>      if (name.isFile&&  name.hasExt(["ini", "conf"]))
>      {
>          // do something
>      }
> }
>
> Yes, that is a horrible implementation, but I can't be bothered with trying to make it nice and simple right now, I'm in a rush. Sorry. :)
>
> I often have to search for files that have a certain extension. Having to expand the code to the following becomes ugly real fast:
>
> foreach (string name; dirEntries(curdir, SpanMode.shallow))
> {
>      if (name.isFile&&  name.hasExt.tolower == "ini" ||
>                     name.hasExt.tolower == "conf"))
>      {
>          // do something
>      }
> }

Would be nice eg to match a whole set of image formats at once (while also caring for "uncased" matching). But why a range?

Denis
-- 
_________________
vita es estrany
spir.wikidot.com

April 01, 2011
Match a single extension or any number of extensions. I've said "range", but I didn't mean a custom type. Just that it works with either 1 value or an array of values.
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