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.




 
: read  bl parse ;
: not-empty? ( c-addr u -- c-addr u true | false ) ?dup-if true else drop false then ;
: third-to-last  2rot ;
: second-to-last  2swap ;
 
: quibble
	." {"
	read read begin read not-empty? while third-to-last type ." , " repeat
	second-to-last not-empty? if type then
	not-empty? if ."  and " type then
	." }" cr ;
 
quibble
quibble ABC
quibble ABC DEF
quibble ABC DEF G H
 