Problem Statement

Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.

The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or provided in a standard library, show that. Otherwise implement the minimum length greedy algorithm from Wikipedia. Show your routine working on a sample of text at two different wrap columns.

Wrap text using a more sophisticated algorithm such as the Knuth and Plass TeX algorithm.
If your language provides this, you get easy extra credit, but you must reference documentation indicating that the algorithm is something better than a simple minimum length algorithm. If you have both basic and extra credit solutions, show an example where the two algorithms give different results.

Let's start with the solution:

# Simple greedy algorithm.
# Note: very long words are not truncated.
# input: a string
# output: an array of strings
def wrap_text(width):
  reduce splits("\\s+") as $word
    ([""];
     .[length-1] as $current
     | ($word|length) as $wl
     | (if $current == "" then 0 else 1 end) as $pad
     | if $wl + $pad + ($current|length) <= width
       then .[-1] += ($pad * " ") + $word
       else . + [ $word]
       end );

"aaa bb cc ddddd" | wrap_text(6)[]  # wikipedia example

"aaa bb cc ddddd" | wrap_text(5)[]

$ jq -M -R -s -r -f Word_wrap.jq Russian.txt
советских военных судов и самолетов была
отмечена в Японском море после появления
там двух американских авианосцев. Не
менее 100 советских самолетов поднялись
в воздух, когдаамериканские авианосцы
"Уинсон" и "Мидуэй" приблизились на 50
миль к Владивостоку.