Ruby variable scoping is killing me - ruby

Question

I have a parser that reads files. Inside a file, you can declare a filename and the parser will go and read that one, then when it is done, pick up right where it left off and continue. This can happen as many levels deep as you want.
Sounds pretty easy so far. All I want to do is print out the file names and line numbers.
I have a class called FileReader that looks like this:
class FileReader
attr_accessor :filename, :lineNumber
def initialize(filename)
#filename = filename
#lineNumber = 0
end
def readFile()
# pseudocode to make this easy
open #filename
while (lines)
#lineNumber = #lineNumber + 1
if(line startsWith ('File:'))
FileReader.new(line).readFile()
end
puts 'read ' + #filename + ' at ' + #lineNumber.to_s()
end
puts 'EOF'
end
end
Simple enough. So lets say I have a file that refers other files like this. File1->File2->File3. This is what it looks like:
read File1 at 1
read File1 at 2
read File1 at 3
read File2 at 1
read File2 at 2
read File2 at 3
read File2 at 4
read File3 at 1
read File3 at 2
read File3 at 3
read File3 at 4
read File3 at 5
EOF
read File3 at 5
read File3 at 6
read File3 at 7
read File3 at 8
EOF
read File2 at 4
read File2 at 5
read File2 at 6
read File2 at 7
read File2 at 8
read File2 at 9
read File2 at 10
read File2 at 11
And that doesnt make any sense to me.
File 1 has 11 lines
File 2 has 8 lines
File 3 has 4 lines
I would assume creating a new object would have its own scope that doesn't affect a parent object.

Answer 1

class FileReader
def initialize(filename)
#filename = filename
end
def read_file
File.readlines(#filename).map.with_index {|l, i|
next "read #{#filename} at #{i}" unless l.start_with?('File:')
FileReader.new(l.gsub('File:', '').chomp).read_file
}.join("\n") << "\nEOF"
end
end
puts FileReader.new('File1').read_file
or just
def File.read_recursively(filename)
readlines(filename).map.with_index {|l, i|
next "read #{filename} at #{i}" unless l.start_with?('File:')
read_recursively(l.gsub('File:', '').chomp)
}.join("\n") << "\nEOF"
end
puts File.read_recursively('File1')

Answer 2

I agree that something in your rewriting code has obfuscated the problem. Yes, those instance variables should be local to the instance.
Watch out for things where a block of code or conditional may be returning a value and assigning it to the instance variable... for example, if your open statement uses the next block and returns the filename somehow... #filename = open(line) {}
I say this because the filename obviously didn't change back after the EOF

Answer 3

This is what I came up with. It's not pretty but I tried to stay as close to your code as possible while Ruby-fying it too.
file_reader.rb
#!/usr/bin/env ruby
class FileReader
attr_accessor :filename, :lineNumber
def initialize(filename)
#filename = filename
#lineNumber = 0
end
def read_file
File.open(#filename,'r') do |file|
while (line = file.gets)
line.strip!
#lineNumber += 1
if line.match(/^File/)
FileReader.new(line).read_file()
end
puts "read #{#filename} at #{#lineNumber} : Line = #{line}"
end
end
puts 'EOF'
end
end
fr = FileReader.new("File1")
fr.read_file
And the File1, File2, and File3 looking like:
Line 1
Line 2
Line 3
File2
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11
Output:
read File1 at 1 : Line = Line 1
read File1 at 2 : Line = Line 2
read File1 at 3 : Line = Line 3
read File2 at 1 : Line = Line 1
read File2 at 2 : Line = Line 2
read File2 at 3 : Line = Line 3
read File2 at 4 : Line = Line 4
read File3 at 1 : Line = Line 1
read File3 at 2 : Line = Line 2
read File3 at 3 : Line = Line 3
read File3 at 4 : Line = Line 4
EOF
read File2 at 5 : Line = File3
read File2 at 6 : Line = Line 6
read File2 at 7 : Line = Line 7
read File2 at 8 : Line = Line 8
EOF
read File1 at 4 : Line = File2
read File1 at 5 : Line = Line 5
read File1 at 6 : Line = Line 6
read File1 at 7 : Line = Line 7
read File1 at 8 : Line = Line 8
read File1 at 9 : Line = Line 9
read File1 at 10 : Line = Line 10
read File1 at 11 : Line = Line 11
EOF
To reiterate we really have to see your code to know where the problems is.
I understand you thinking it has something to do with variable scoping so the question makes sense to me.
For the other people. Please be a little more kind to the novices trying to learn. This is supposed to be a place for helping. Thank you. </soapbox>