Return line of text similar to readlines

[gazayas]

LexNode objects currently look like this.

Masamune::AbstractSyntaxTree.new("x = 1\n y = 2").lex_nodes
=> 
[#<Masamune::LexNode:0x00007fe2f0655498 @ast_id=226780, @index=0, @position=[1, 0], @state=CMDARG, @token="x", @type=:ident>,            
 #<Masamune::LexNode:0x00007fe2f06552b8 @ast_id=226780, @index=1, @position=[1, 1], @state=CMDARG, @token=" ", @type=:sp>,               
 #<Masamune::LexNode:0x00007fe2f06550d8 @ast_id=226780, @index=2, @position=[1, 2], @state=BEG, @token="=", @type=:op>,                  
 #<Masamune::LexNode:0x00007fe2f0654f20 @ast_id=226780, @index=3, @position=[1, 3], @state=BEG, @token=" ", @type=:sp>,                  
 #<Masamune::LexNode:0x00007fe2f0654d90 @ast_id=226780, @index=4, @position=[1, 4], @state=END, @token="1", @type=:int>,                 
 #<Masamune::LexNode:0x00007fe2f0654c28 @ast_id=226780, @index=5, @position=[1, 5], @state=BEG, @token="\n", @type=:nl>,                 
 #<Masamune::LexNode:0x00007fe2f0654a70 @ast_id=226780, @index=6, @position=[2, 0], @state=BEG, @token=" ", @type=:sp>,                  
 #<Masamune::LexNode:0x00007fe2f0654890 @ast_id=226780, @index=7, @position=[2, 1], @state=CMDARG, @token="y", @type=:ident>,            
 #<Masamune::LexNode:0x00007fe2f0654728 @ast_id=226780, @index=8, @position=[2, 2], @state=CMDARG, @token=" ", @type=:sp>,               
 #<Masamune::LexNode:0x00007fe2f0654598 @ast_id=226780, @index=9, @position=[2, 3], @state=BEG, @token="=", @type=:op>,                  
 #<Masamune::LexNode:0x00007fe2f0654430 @ast_id=226780, @index=10, @position=[2, 4], @state=BEG, @token=" ", @type=:sp>,
 #<Masamune::LexNode:0x00007fe2f06542a0 @ast_id=226780, @index=11, @position=[2, 5], @state=END, @token="2", @type=:int>]

I would like to write something like msmn.lines to get all the lines like a File object does. Since all of the line numbers and tokens are here, I think we could build the lines pretty easily.