From: "David A. Black" <dblack@...>
Date: 2008-09-28T22:00:19+09:00
Subject: Re: Merging hashes and having trouble with variable scope!

Hi --

On Sun, 28 Sep 2008, Andy Pipes wrote:

> Hi.
>
> Caveat: I'm just learning Ruby coming from some basic PHP programming.
>
> In the following I am aiming to peer into two tab-separated files with
> some vegetable facts on them. In the first 'column' of each file there
> are vegetable names, followed by the data. However, whilst some of the
> vegetables have the same name, others do not. My ultimate aim is to take
> the contents of each of these files, and merge them into a master file,
> and for those vegetables that have data in both files to merge the data.
>
> So a line from file 1 might read:
>
> Watermelon 60-80 4-10
>
> and one file two:
>
> Watermelon 1/2oz. 34 12-26 24-48
>
> and in the masterfile I would want:
>
> Watermelon 60-80 4-10 1/2oz. 34 12-26 24-48.
>
> I have been trying unsuccessfully for the past two days to do this so
> any help is greatly appreciated!!! :)
>
> Here's some sample code:

Back at ya :-) Try this. I've changed key names just to fit things on
single lines and make my code look even slicker than it is :-) You can
change all that back, of course. The main thing is to absolutely not
write that same splitting routine five times! I've syphoned it off
into a method (and you could possibly even trim the arguments down if
you automated the "min"/"max" parts).

So, see if this helps as a starting point. It doesn't distinguish
among different vegetables, but that could be added.

@v = {}

def split_or_double(string, key1, key2)
   @v[key1], @v[key2] = string.split(/-/)
   @v[key2] || @v[key1]
end

File.foreach("vegetables.txt") do |line|
   name, temp, germ_days = line.split
   split_or_double(temp, :temp_max, :temp_min)
   split_or_double(germ_days, :germ_days_max, :germ_days_min)
end

File.foreach("vegetables2.txt") do |line|
   name2, crop_yield, row_space, plant_space, harvest_days = line.split
   split_or_double(row_space, :min_row_space, :max_row_space)
   split_or_double(plant_space, :min_plant_space, :max_plant_space)
   split_or_double(harvest_days, :min_harvest, :max_harvest)
end

p @v


David

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