Added additional expansion formats

[daudi]

Added expansion formats for amount1 and amount2, and date1 and date2. These can be used to find transactions with exact amounts or on exact dates, or in ranges. For example, to show transactions between two dates, in the ledger reports you can use:

%(binary) -f %(ledger-file) reg %(account) --display 'd>= [%(date1)] and d <= [%(date2)]'

[bcc32]

It seems like it would be nicer for the date format specifier to prompt for the date using ledger-read-date, instead of making the user just type a string.

I'm a little confused by the proposed "amount" format specifier---is it just supposed to be some number, or a commoditized amount, or something else?

Also, it seems a little weird to define date1 and date2 with the expectation that any reports that only use a single date should use %(date1)? FWIW, you can just use the same format specifier twice in one report. You'll get prompted with the same string each time, but otherwise it works okay, and I feel it would make the defaults a little cleaner.

[daudi]

All good points - I'm very much as the lower end of the elisp learning curve.

1. Yes, ledger-read-date is better
2. Yes, just an amount. In my report definition I have %(binary) -f %(ledger-file) reg %(account) --display 'amount == %(amount1) GBP' so the commodity is hard-coded there, but now I realise that is somewhat limiting. I'll have a go at making it possible to specify the commodity
3. My misunderstanding, yes, I see that it can just use one version of date

Thanks for your feedback.