Document should cover CONVERT()

[blais]

Original report by Martin Michlmayr (Bitbucket: tbm13, GitHub: tbm).

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I want to use CONVERT() to convert something to its historical cost (i.e. exchange rate on date of transaction, without later revaluation).

I don't think this is currently possible with beancount. Maybe CONVERT() can be extended to allow an optional DATE.

Example:

2014-01-01 open Expenses:Test
2014-01-01 open Assets:Cash

2014-01-09 * "Test" "Test 1"
     Expenses:Test           10.00 EUR @ 0.8283 GBP
     Assets:Cash             -8.28 GBP

2014-06-10 * "Test" "Test 2"
     Expenses:Test           10.00 EUR @ 0.8106 GBP
     Assets:Cash             -8.11 GBP

2014-07-30 * "Test" "Test 3"
     Expenses:Test           10.00 EUR @ 0.7914 GBP
     Assets:Cash             -7.91 GBP

2014-09-11 price EUR 0.8011 GBP

2014-12-31 price EUR 0.7825 GBP

select date, position, convert(position, "GBP"), balance where account ~ 'Expenses'
   date    position  convert_po  balance 
---------- --------- ---------- ---------
2014-01-09 10.00 EUR 7.8250 GBP 10.00 EUR
2014-06-10 10.00 EUR 7.8250 GBP 20.00 EUR
2014-07-30 10.00 EUR 7.8250 GBP 30.00 EUR

It uses the latest exchange rate (0.7825) for all transactions.

[blais]

Original comment by Patrick Ruckstuhl (GitHub: tarioch).

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This is possible, I'm using this. It's the third argument. e.g. convert(position, "GBP", date)

[blais]

Original comment by Martin Michlmayr (Bitbucket: tbm13, GitHub: tbm).

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Thanks, Patrick. This issue is a documentation issue then since this isn't mention anywhere.

After adding explicit price entries, it works:

beancount> select date, position, convert(position, "GBP", date), balance where account ~ 'Expenses'
   date    position  convert_po  balance 
---------- --------- ---------- ---------
2014-01-09 10.00 EUR 8.2830 GBP 10.00 EUR
2014-06-10 10.00 EUR 8.1060 GBP 20.00 EUR
2014-07-30 10.00 EUR 7.9140 GBP 30.00 EUR

The converted positions have 4 digits of precision: 8.1060. Is there a way to round this?

[blais]

Original comment by Martin Michlmayr (Bitbucket: tbm13, GitHub: tbm).

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Patrick, do you know how to specify a specific date. A string ("2018-03-15") doesn't work.

[blais]

Original comment by Patrick Ruckstuhl (GitHub: tarioch).

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yes, use #"2018-02-20"

[blais]

Original comment by Martin Blais (Bitbucket: blais, GitHub: blais).

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The list of available functions is located in this file: https://bitbucket.org/blais/beancount/src/358d24867d12e7145f7fe2c321f3f809089051fa/beancount/query/query_env.py?at=default&fileviewer=file-view-default#query_env.py-638

I'd like to eventually generate a full list or serve it from the help.

[blais]

Original comment by Martin Michlmayr (Bitbucket: tbm13, GitHub: tbm).

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Thanks for this link.

Can you change the ticket component to docs and change the title.

[blais]

Original comment by Martin Michlmayr (Bitbucket: tbm13, GitHub: tbm).

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Changing to docs.