Problem Statement

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

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

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

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

Let's start with the solution:

def quibble:
  if length == 0 then "" 
  elif length == 1 then .[0]
  else (.[0:length-1] | join(", ")) + " and " + .[length-1]
  end
  | "{" + . + "}";

( [], ["ABC"],  ["ABC", "DEF"],  ["ABC", "DEF", "G", "H"]) | quibble

jq -n -r -f Comma_quibbling.jq
{}
{ABC}
{ABC and DEF}
{ABC, DEF, G and H}