Comma quibbling is a task originally set by Eric Lippert in his blog.



Task

Write a function to generate a string output which is the concatenation of input words from a list/sequence where:

 An input of no words produces the output string of just the two brace characters "{}".
 An input of just one word, e.g. ["ABC"], produces the output string of the word inside the two braces, e.g. "{ABC}".
 An input of two words, e.g. ["ABC", "DEF"], produces the output string of the two words inside the two braces with the words separated by the string " and ", e.g. "{ABC and DEF}".
 An input of three or more words, e.g. ["ABC", "DEF", "G", "H"], produces the output string of all but the last word separated by ", " with the last word separated by " and " and all within braces; e.g. "{ABC, DEF, G and H}".


Test your function with the following series of inputs showing your output here on this page:

 [] # (No input words).
 ["ABC"]
 ["ABC", "DEF"]
 ["ABC", "DEF", "G", "H"]


Note: Assume words are non-empty strings of uppercase characters for this task.




 
do
        read in$
        if in$ ="END" then wait
        w =wordCount( in$)
        select case w
            case 0
                o$ ="{}"
            case 1
                o$ ="{" +in$ +"}"
            case 2
                o$ ="{" +word$( in$, 1) +" and " +word$( in$, 2) +"}"
            case else
                o$ ="{"
                o$ =o$ +word$( in$, 1)
                for k =2 to w -1
                    o$ =o$ +", " +word$( in$, k)
                next k
                o$ =o$ +" and " +word$( in$, w) +"}"
        end select
        if w =1 then
            print "'"; in$; "'"; " held "; w; " word. "; tab( 30); o$
        else
            print "'"; in$; "'"; " held "; w; " words. "; tab( 30); o$
        end if
    loop until 0
 
    wait
 
    function wordCount( IN$)
        wordCount =1
        for i =1 to len( IN$)
            if mid$( IN$, i, 1) =" " then wordCount =wordCount +1
        next i
    end function
 
    end
 
    data ""                 'No input words.
    data "ABC"              'One input word.
    data "ABC DEF"          'Two words.
    data "ABC DEF G"        'Three words.
    data "ABC DEF G H"      'Four words.
 
    data "END"              'Sentinel for EOD.
 