Library to determine indefinite article of a noun?

问题:

This question already has answers here:

How can I correctly prefix a word with “a” and “an”? (23 answers)

Closed 7 years ago.

Are there any libraries for .NET that deal with determining the Indefinite Article of a noun?

My crude attempt is below, which will probably work for 99% of my usage (which is acceptable) just wondering if there are any established alternatives?

public static string GetIndefinateArticle(string noun)
{
    if(string.IsNullOrEmpty(noun))
        return noun;

    var first = noun[0];

    if(first == 'a' ||
        first == 'e' ||
        first == 'i' ||
        first == 'o')
        return "an " + noun;

    return "a " + noun;
}

Update: Eamon pointed out a duplicate question in the comments: How can I correctly prefix a word with "a" and "an"? I'll leave this Q here and open though, because I still don't really have an answer.

回答1:

If this is something you need done seriously, you may consider porting the Ruby Linguistics (English) library to .Net. It's open source & does a pretty good job of calculating the correct articles.

http://deveiate.org/projects/Linguistics/

回答2:

I've ported a function from Python that correctly determines vowel sounds in C# and posted it as an answer to the question Programmatically determine whether to describe an object with a or an?. You can see the code snippet here. It is indeed more complicated than just looking at vowels.

回答3:

I implemented a library to do this: https://github.com/eamonnerbonne/a-vs-an; it's AvsAn on nuget. It's based on real usage patterns in wikipedia and hence even deals well with tricky things like...

• "an 0800 number"
• "an ∞ of oregano"
• "a NASA flight"
• "an NSA analyst"

In other words, it usually even will deal reasonably with many things that aren't normal words.

回答4:

Since all you're really doing is check for patterns in the string, you could use a regular expression. This should also allow for future expansion of letter combos like lutge098 talked about:

public static string GetIndefinateArticle(string noun)
{
    if (Regex.IsMatch(noun, "^([aeio]|un|ul)", RegexOptions.IgnoreCase))
        return "an " + noun;
    else
        return "a " + noun;
}

回答5:

What i would do is:

var first = noun[0];
var second = noun[1];

if(first == 'a' ||
    first == 'e' ||
    first == 'i' ||
    first == 'o')
    return "an " + self;

if(first == 'u')
    if (second == 'n' ||
        second == 'l')
        return "an " + self;

if(first == 'h')
    if (second == 'i')
        return "an " + self;

return "a " + self;

So you can define some cases where some letters in combination with each other form a certain sound. Hope this helps.

回答6:

No, and it isn't as simple as just whacking an extra n when the next character is a vowel. There are a whole bunch of subtleties around it, and you also have to consider how to handle h - some use an before it, some don't.

This is also English specific, and the framework is relatively language agnostic.

This means you will have to cook it up yourself :)

回答7:

The basic rule of "a" before a consonant and "an" before a vowel gets you most of the way there, that would be very easy to implement. The problem is the "sounds-like a vowel = an" case -- that would be much harder.