Question

I have this raw text:

________________________________________________________________________________________________________________________________
Pos Car  Competitor/Team                Driver                   Vehicle              Cap   CL Laps     Race.Time Fastest...Lap

1     6  Jason Clements                 Jason Clements           BMW M3               3200       10     9:48.5710   3 0:57.3228*
2    42  David Skillender               David Skillender         Holden VS Commodore  6000       10     9:55.6866   2 0:57.9409 
3    37  Bruce Cook                     Bruce Cook               Ford  Escort         3759       10     9:56.4388   4 0:58.3359 
4    18  Troy Marinelli                 Troy Marinelli           Nissan  Silvia       3396       10     9:56.7758   2 0:58.4443 
5    75  Anthony Gilbertson             Anthony Gilbertson       BMW M3               3200       10    10:02.5842   3 0:58.9336 
6    26  Trent Purcell                  Trent Purcell            Mazda RX7            2354       10    10:07.6285   4 0:59.0546 
7    12  Scott Hunter                   Scott Hunter             Toyota  Corolla      2000       10    10:11.3722   5 0:59.8921 
8    91  Graeme Wilkinson               Graeme Wilkinson         Ford  Escort         2000       10    10:13.4114   5 1:00.2175 
9     7  Justin Wade                    Justin Wade              BMW M3               4000       10    10:18.2020   9 1:00.8969 
10   55  Greg Craig                     Grag Craig               Toyota  Corolla      1840       10    10:18.9956   7 1:00.7905 
11   46  Kyle Orgam-Moore               Kyle Organ-Moore         Holden VS Commodore  6000       10    10:30.0179   3 1:01.6741 
12   39  Uptiles Strathpine             Trent Spencer            BMW Mini Cooper S    1500       10    10:40.1436   2 1:02.2728 
13  177  Mark Hyde                      Mark Hyde                Ford  Escort         1993       10    10:49.5920   2 1:03.8069 
14   34  Peter Draheim                  Peter Draheim            Mazda RX3            2600       10    10:50.8159  10 1:03.4396 
15    5  Scott Douglas                  Scott Douglas            Datsun  1200         1998        9     9:48.7808   3 1:01.5371 
16   72  Paul Redman                    Paul Redman              Ford  Focus          2lt         9    10:11.3707   2 1:05.8729 
17    8  Matthew Speakman               Matthew Speakman         Toyota  Celica       1600        9    10:16.3159   3 1:05.9117 
18   74  Lucas Easton                   Lucas Easton             Toyota  Celica       1600        9    10:16.8050   6 1:06.0748 
19   77  Dean Fuller                    Dean Fuller              Mitsubishi  Sigma    2600        9    10:25.2877   3 1:07.3991 
20   16  Brett Batterby                 Brett Batterby           Toyota  Corolla      1600        9    10:29.9127   4 1:07.8420 
21   95  Ross Hurford                   Ross Hurford             Toyota  Corolla      1600        8     9:57.5297   2 1:12.2672 
DNF  13  Charles Wright                 Charles Wright           BMW 325i             2700        9     9:47.9888   7 1:03.2808 
DNF  20  Shane Satchwell                Shane Satchwell          Datsun  1200 Coupe   1998        1     1:05.9100   1 1:05.9100 

Fastest Lap Av.Speed Is 152kph, Race Av.Speed Is 148kph
R=under lap record by greatest margin, r=under lap record, *=fastest lap time
________________________________________________________________________________________________________________________________
Issue# 2 - Printed Sat May 26 15:43:31 2012                     Timing System By NATSOFT [phone] www.natsoft.com.au/results
Amended 

I need to parse it into an object with the obvious Position, Car, Driver etc fields. The issue is I have no idea on what sort of strategy to use. If I split it on whitespace, I would end up with a list like so:

["1", "6", "Jason", "Clements", "Jason", "Clements", "BMW", "M3", "3200", "10", "9:48.5710", "3", "0:57.3228*"]

Can you see the issue. I cannot just interpret this list, because people may have just 1 name, or 3 words in a name, or many different words in a car. It makes it impossible to just reference the list using indexes alone.

What about using the offsets defined by the column names? I can’t quite see how that could be used though.

Edit: So the current algorithm I am using works like this:

1. Split the text on new line giving a collection of lines.
2. Find the common whitespace characters FURTHEST RIGHT on each line. I.e. the positions (indexes) on each line where every other
   line contains whitespace. EG:
3. Split the lines based on those common characters.
4. Trim the lines

Several issues exist:

If the names contain the same lengths like so:

Jason Adams
Bobby Sacka
Jerry Louis

Then it will interpret that as two separate items: (["Jason" "Adams", "Bobby", "Sacka", "Jerry", "Louis"]).

Whereas if they all differed like so:

Dominic Bou
Bob Adams
Jerry Seinfeld

Then it would correctly split on the last ‘d’ in Seinfeld (and thus we’d get a collection of three names(["Dominic Bou", "Bob Adams", "Jerry Seinfeld"]).

It’s also quite brittle. I am looking for a nicer solution.

Answer 1

You can use the fixed_width gem.

Your given file can be parsed with the following code:

require 'fixed_width'
require 'pp'

FixedWidth.define :cars do |d|
  d.head do |head|
    head.trap { |line| line !~ /\d/ }
  end
  d.body do |body|
    body.trap { |line| line =~ /^(\d|DNF)/ }
    body.column :pos, 4
    body.column :car, 5
    body.column :competitor, 31
    body.column :driver, 25
    body.column :vehicle, 21
    body.column :cap, 5
    body.column :cl_laps, 11
    body.column :race_time, 11
    body.column :fast_lap_no, 4
    body.column :fast_lap_time, 10
  end
end

pp FixedWidth.parse(File.open("races.txt"), :cars)

The trap method identifies the lines in each section. I used regex:

• The head regex looks for lines that don’t contain a digit.
• The body regex looks for lines starting with a digit or “DNF”

Each section must include the line immediately after the last. The column definitions simply identify the number of columns to grab. The library strips whitespace for you. If you wanted to produce a fixed-width file, you can add alignment parameters, but it doesn’t appear you will need that.

The result is a hash that starts like this:

{:head=>[{}, {}, {}],
 :body=>
  [{:pos=>"1",
    :car=>"6",
    :competitor=>"Jason Clements",
    :driver=>"Jason Clements",
    :vehicle=>"BMW M3",
    :cap=>"3200",
    :cl_laps=>"10",
    :race_time=>"9:48.5710",
    :fast_lap_no=>"3",
    :fast_lap_time=>"0:57.3228"},
   {:pos=>"2",
    :car=>"42",
    :competitor=>"David Skillender",
    :driver=>"David Skillender",
    :vehicle=>"Holden VS Commodore",
    :cap=>"6000",
    :cl_laps=>"10",
    :race_time=>"9:55.6866",
    :fast_lap_no=>"2",
    :fast_lap_time=>"0:57.9409"},