Read n lines above the current line in Ruby?

Question

I have a data file that looks like this:

Things ├── Foo │  ├── 1. Item One │  ├── 2. Item Two │  ├── 3. Item Three │  ├── 4. Item Four │  ├── 5. Item Five │  └── 6. Item Six ├── Bar │  ├── 1. Item Seven │  ├── 2. Item Eight │  ├── 3. Item Nine 

What I'm trying to do is find a specific line, the number associated with it, as well as a subheading that is part of ('Foo' or 'Bar')

Pretty easy to grab the item and number:

 str = "Item One" data.each_line do |line| if line =~ /#{str}/ /(?<num>\d).\s(?<item>.*)/ =~ line end end 

But I'm not sure how to get the subtitle. I thought that as soon as I found the line, I could count from this point using the number. Are there any reading lines or a search command or some of them that can do this?

Appreciate the help!

Answer 1

I came up with below, this seems to work:

 data = <<-EOF Things ├── Foo │ ├── 1. Item One │ ├── 2. Item Two │ ├── 3. Item Three │ ├── 4. Item Four │ ├── 5. Item Five │ └── 6. Item Six ├── Bar │ ├── 1. Item Seven │ ├── 2. Item Eight │ ├── 3. Item Nine EOF str = "Item One" data.lines.each_with_index do |line, i| if /(?<num>\d)\.\s+#{str}/ =~ line /(?<var>\w+)/ =~ data.lines[i - (n = $~[:num]).to_i] p [n, str, var] # ["1", "Item One", "Foo"] end end 

(n = $~[:num]) needed to save the captured num value from

 if /(?<num>\d)\.\s+#{str}/ =~ line 

into a variable (say n ), since the last matching data represented by the global variable $~ will be overwritten during the next regular expression contained in the statement

 /(?<var>\w+)/ =~ data.lines[i - (num = $~[:num]).to_i] 

and if we do not save it for later use, we will lose the captured num value.

Answer 2

Here's another way (using @Wand data ):

 LAZY_T = "├── " target = "Item Four" str = data.split(/\n#{LAZY_T}/).find { |s| s =~ /\b#{target}\b/ } str && [str[/[a-zA-Z]+/], str[/(\d+)\.\s#{target}\b/,1]] #=> ["Foo", "4"] 

The first line extends the applicable part of the line ( "Foo" or "Bar" ), if any. The second line retrieves the two desired items.

Note:

 LAZY_T.split('').map(&:ord) #=> [9500, 9472, 9472, 32]