[Haskell-cafe] hledger subcommand detection, RFC

[Simon Michael]

When I split up the hledger package, I always intended to make the hledger program act as a single front end for hledger-* executables. I finally got around to trying that, just pushed to darcs [1]. So hledger now searches your PATH at startup and offer any hledger-* executables as subcommands. To make this fully modular, so that options can be reused and third-party add-ons don't need to be baked in to hledger in any way, there has also been a rather extensive options overhaul, using cmdargs. Below is an example [2] of the new help output with all hledger-* packages plus a local hledger-report.hs script installed.

I'm not sure if this is fully safe, cross-platform, robust, quick enough to be unnoticeable, etc. I have about 20 dirs and 4k files in my PATH. I haven't noticed a slowdown on macbook or vps, but have not measured. More testing of this on diverse platforms and machines, or code review, would be very welcome.

-Simon

[1] http://joyful.com/darcsden/simon/hledger/browse/hledger/Hledger/Cli/Options.hs#L-330

[2]
$ hledger
hledger [COMMAND] ... [OPTIONS]
  run the specified hledger command. hledger COMMAND --help for more detail.
  In general, COMMAND should precede OPTIONS.

Misc commands:
  add       prompt for new transactions and append them to the journal
  convert   show the specified CSV file as hledger journal entries
  test      run self-tests, or just the ones matching REGEXPS

Report commands:
  accounts  (or balance) show matched accounts and their balances
  entries   (or print) show matched journal entries
  postings  (or register) show matched postings and running total
  activity  show a barchart of transactions per interval
  stats     show quick statistics for a journal (or part of it)

Add-on commands found:
  chart     [-- OPTIONS]   run the hledger-chart program
  interest  [-- OPTIONS]   run the hledger-interest program
  report    [-- OPTIONS]   run the hledger-report program
  vty       [-- OPTIONS]   run the hledger-vty program
  web       [-- OPTIONS]   run the hledger-web program

  -? --help     Display help message
     --debug    Show extra debug output
  -V --version  Print version information

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20110825/373862a9/attachment.htm>