why does psych yaml interpreter add line breaks around 80 characters?

Question

Psych is the default yaml engine since ruby 1.9.3

Why, oh why does psych add a line break in its output? Check the example below.

ruby -v # => ruby 1.9.3p374 (2013-01-15 revision 38858) [x86_64-linux]
require 'yaml'

"this absolutely normal sentence is more than eighty characters long because it IS".to_yaml
# => "--- this absolutely normal sentence is more than eighty characters long because it\n    IS\n...\n"

YAML::ENGINE.yamler = 'syck'

"this absolutely normal sentence is more than eighty characters long because it IS".to_yaml
# => "--- this absolutely normal sentence is more than eighty characters long because it IS\n"

Answer 1

You'll have to configure psych’s #to_yaml options. You'll most likely find it here:

ruby-1.9.3-p125/ext/psych/emitter.c

And then you can do something like this:

yaml.to_yaml(options = {:line_width => -1})

Answer 2

yaml.to_yaml(options = {:line_width => -1})

is ok to solve the problem.

but RuboCop say

Useless assignment to variable - options.

so

yaml.to_yaml(line_width: -1)

is better.