Utility function for 'a' & 'an'

[Codex NG]

Might not seem important, I like to sometimes write little utility functions although I don't always use them.

This is a simple function (if it doesn't already exist) which will allow you to state where the word a (yes a is a word) or an will be used in a sentence.

Unfortunately this only pertains to english, I am sure you can adapt it to your native language based on its rules of grammar.

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function aOrAn(word)
    local vowels = {'a', 'e', 'i', 'o', 'u', 'x'}
    return isInArray(vowels, word:sub(1, 1):lower()) and ' an '..word or ' a '..word
end

If you don't have an isInArray function in your distro or whatever you are working on, you can always use this function definition below.

function isInArray(a, x)
    for k, v in pairs(a) do
        if v == x then
            return true
        end
    end
    return false
end

So how can this be used.. Lets take a look at an example

function aOrAn(word)
    local vowels = {'a', 'e', 'i', 'o', 'u', 'x'}
    return isInArray(vowels, word:sub(1, 1):lower()) and ' an '..word or ' a '..word
end

local name = 'elephant'
print("You have summoned"..aOrAn(name)..".")
-- output
You have summoned an elephant.

Lets try another

local name = 'deer'
print("You have summoned"..aOrAn(name)..".")
-- output
You have summoned a deer.

One more

local name = 'Xray'
print("You went and got"..aOrAn(name)..".")
-- output
You went and got an Xray.

Its not perfect by any means, but its definitely helpful to have functions which can simplify things at times.

 

[Mkalo]

function aOrAn(word)
    return word:gsub("^.", function(char) return ("aeiou"):find(char:lower()) and ('an ' .. char) or ('a ' .. char) end)
end

Better (wont consider characters that are not letters in the beginning of the word like spaces etc)

function aOrAn(word)
    return word:gsub("^(.-)(%a)", function(_, char) return _ .. (("aeiou"):find(char:lower()) and "an " or "a ") .. char end)
end

Not using gsub:

function aOrAn(word)
    return ("aeiou"):find(word:sub(1, 1):lower()) and "an " .. word or "a " .. word
end

Let it be clear that i'm posting this for people to see another way to see how it could be done (without is in array and using gsub)