Ruby: split string on parentheses and space-CodePudding

I want to use RegEx to split a string with space and parentheses

Example:

"The (New York city) :) is big"

=> Output:

["The", "New York city", ":)", "is", "big"]

I have tried this expression: /\([^\)] ?[\)]|[^ ] /

but the parentheses are still there so not good.

["The", "(New York city)", ":)", "is", "big"]

Has somebody any idea, please ? Thanks

CodePudding user response：

Actually, you can capture the parts you need and then, after applying scan, subtract all nil array items (that will occur since every match will only have a single capturing group value filled):

text = "The (New York city) :) is big"
arr = text.scan(/\(([^()] )\)|(\S )/).flatten - [nil]
# Or 
# arr = text.scan(/\(([^()] )\)|(\S )/).flatten.compact
p arr # => ["The", "New York city", ":)", "is", "big"]

See the Ruby demo and the Rubular demo.

Details:

\( - a ( char
([^()] ) - Group 1: one or more chars other than ( and )
\) - a ) char
| - or
(\S ) - Group 2: one or more non-whitespace chars.

CodePudding user response：

One may write:

str = "The (New York city) :) is big"

str.gsub(/\(.*?\)|\S /).with_object([]) do |s,a|
  a << (s[0]=='(' && s[-1] == ')' ? s[1..-2] : s)
end

This uses the form of String#gsub that takes one argument--here a regular expression--and no block, returning an enumerator:

enum = str.gsub(/\(.*?\)|\S /)
  #=> #<Enumerator: "The (New York City) :) is big":gsub(/\(.*?\)|\S /)>

We can see the (string) objects that will be generated by the enumerator by converting it to an array:

enum.to_a
  #=> ["The", "(New York City)", ":)", "is", "big"]

We can make the regular expression self-documenting by expressing it in free-spacing mode:

/
\(    # match '('
.*?   # match zero or more characters, lazily
\)    # match ')'
|     # or
\S    # match one or more characters other than white spaces
/x    # free-spacing regex definition mode