I have a Array of Hashes like: 
var = [
{
'id_a' => '1',
'id_b' => '5',
'value_x' => '10'
'value_y' => '5'
},
{
'id_a' => '2',
'id_b' => '3',
'value_x' => '20'
'value_y' => '10'
},
{
'id_a' => '2',
'id_b' => '3',
'value_x' => '30'
'value_y' => '20'
},
{
'id_a' => '3',
'id_b' => '7',
'value_x' => '15'
'value_y' => '15'
}
]

[download]
... ordered by the "id" fields. I wish to find the hashes with duplicate "id"s and "merge" them together. That is, if there are two (or more) Hashes with the same "id"s, I want to add the "value"s together and remove the duplicate Hashs. So with the input data given above, the resultant data would look like: 
var = [
{
'id_a' => '1',
'id_b' => '5',
'value_x' => '10'
'value_y' => '5'
},
{
'id_a' => '2',
'id_b' => '3',
'value_x' => '50'
'value_y' => '30'
},
{
'id_a' => '3',
'id_b' => '7',
'value_x' => '15'
'value_y' => '15'
}
]

[download]
Any ideas?

Cheers,
Trev

update: Made it more like the real world...

In reply to Messing about in Arrays of Hashes by nzgrover

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