Replace AlignCommodity with bean-format

AlignCommodity replicates the functionality of the bean-format command
that is shipped with beancount itself. Therefore, we can fully replace
it by having vim invoke bean-format through formatprg.

Even though bean-format's output might differ from AlignCommodity in
significant ways, we feel that using one unified tool is superior to
having several (possibly incompatible) custom implementations. That way,
if bean-format is improved upon in the future, all downstream consumers
profit. For regular usage, however, this change should be transparent.

Note that while bean-format supports a few different ways of formatting
the ledger, we have opted to hard-code one specific setting. This will
match the default behaviour of fava, aligning currencies in column 61.

Managing the arguments passed to bean-format dynamically is considered
out of scope, especially given the fact that the user need only override
formatprg to get a custom setting.

This commit will also drop the g:beancount_separator_col variable and
the tests for AlignCommodity. Ideally, testing will now done upstream
for bean-format itself.

5 files changed, 6 insertions, 135 deletions

diff --git a/README.md b/README.md
index 4c323f9..b2d00a8 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,4 @@ copy all of the files into the appropriate places inside your '.vim' directory.
 
 * Use `:make` to run `bean-check` and load errors in the quickfix window.
 
-* The `AlignCommodity` command lines up all your decimal points.
-
 For full details, see [doc/beancount.txt](doc/beancount.txt).
diff --git a/autoload/beancount.vim b/autoload/beancount.vim
index c5d8f97..91f6999 100644
--- a/autoload/beancount.vim
+++ b/autoload/beancount.vim
@@ -6,52 +6,6 @@ function! s:startswith(string, prefix) abort
     return strpart(a:string, 0, strlen(a:prefix)) == a:prefix
 endfunction
 
-" Align currency on decimal point.
-function! beancount#align_commodity(line1, line2) abort
-    " Save cursor position to adjust it if necessary.
-    let l:cursor_col = col('.')
-    let l:cursor_line = line('.')
-
-    " Increment at start of loop, because of continue statements.
-    let l:current_line = a:line1 - 1
-    while l:current_line < a:line2
-        let l:current_line += 1
-        let l:line = getline(l:current_line)
-        " This matches an account name followed by a space in one of the two
-        " following cases:
-        "  - A posting line, i.e., the line starts with indentation followed
-        "    by an optional flag and the account.
-        "  - A balance directive, i.e., the line starts with a date followed
-        "    by the 'balance' keyword and the account.
-        "  - A price directive, i.e., the line starts with a date followed by
-        "    the 'price' keyword and a currency.
-        let l:end_account = matchend(l:line, '^\v' .
-            \ '[\-/[:digit:]]+\s+balance\s+([A-Z][A-Za-z0-9\-]+)(:[A-Z][A-Za-z0-9\-]*)+ ' .
-            \ '|[\-/[:digit:]]+\s+price\s+\S+ ' .
-            \ '|\s+([!&#?%PSTCURM]\s+)?([A-Z][A-Za-z0-9\-]+)(:[A-Z][A-Za-z0-9\-]*)+ '
-            \ )
-        if l:end_account < 0
-            continue
-        endif
-
-        " Where does the number begin?
-        let l:begin_number = matchend(l:line, '^ *', l:end_account)
-
-        " Look for a minus sign and a number (possibly containing commas) and
-        " align on the next column.
-        let l:separator = matchend(l:line, '^\v([-+])?[,[:digit:]]+', l:begin_number) + 1
-        if l:separator < 0 | continue | endif
-        let l:has_spaces = l:begin_number - l:end_account
-        let l:need_spaces = g:beancount_separator_col - l:separator + l:has_spaces
-        if l:need_spaces < 0 | continue | endif
-        call setline(l:current_line, l:line[0 : l:end_account - 1] . repeat(' ', l:need_spaces) . l:line[ l:begin_number : -1])
-        if l:current_line == l:cursor_line && l:cursor_col >= l:end_account
-            " Adjust cursor position for continuity.
-            call cursor(0, l:cursor_col + l:need_spaces - l:has_spaces)
-        endif
-    endwhile
-endfunction
-
 function! s:count_expression(text, expression) abort
     return len(split(a:text, a:expression, 1)) - 1
 endfunction
diff --git a/doc/beancount.txt b/doc/beancount.txt
index 63e25f5..e3801cc 100644
--- a/doc/beancount.txt
+++ b/doc/beancount.txt
@@ -21,35 +21,6 @@ Contents:
 COMMANDS                                              *beancount-commands*
 
 
-                                                      *beancount-:AlignCommodity*
-:AlignCommodity     Adds spaces between an account and commodity so that the
-                    decimal points of the commodities all occur in the column
-                    given by |g:beancount_separator_col|.  If an amount has no
-                    decimal point, the imaginary decimal point to the right
-                    of the least significant digit will align.
-
-                    The command acts on a range, with the default being the
-                    current line. If the cursor happens to be inside that
-                    range and to the right of the account name, the cursor
-                    will be pushed to the right the appropriate amount, so
-                    that it remains on the same character.
-
-                    The script assumes the use of spaces for alignment. It
-                    does not understand tabs.
-
-                    You can use the following insert-mode remap to
-                    automatically align commodities every time you type a
-                    decimal point: >
-
-                        inoremap . .<C-\><C-O>:AlignCommodity<CR>
-<
-                    You may also want to set other mappings for this. For
-                    example, I use >
-
-                        nnoremap <buffer> <leader>= :AlignCommodity<CR>
-                        vnoremap <buffer> <leader>= :AlignCommodity<CR>
-<
-
                                                       *beancount-:GetContext*
 :GetContext         Uses bean-doctor context to display the context of the
                     current line.
@@ -73,17 +44,16 @@ OPTIONS                                              *beancount-options*
 
   Default value: 0
 
-*g:beancount_separator_col*
-  The column that the decimal separator is aligned to.
-
-  Default value: 50
-
 *b:beancount_root*
   Set the root Beancount file. This is used to gather values for the
   completion. If not set, the current file will be used.
 
   Default value: not set
 
+FORMATTING                                           *beancount-formatting*
+
+The plugin sets |'formatprg'| to 'bean-format -c61' to provide a formatter for
+beancount files. See also |gq|.
 
 COMPLETION                                           *beancount-completion*
 
diff --git a/ftplugin/beancount.vim b/ftplugin/beancount.vim
index b6e3540..ab54905 100644
--- a/ftplugin/beancount.vim
+++ b/ftplugin/beancount.vim
@@ -3,17 +3,14 @@ if exists('b:did_ftplugin')
 endif
 
 let b:did_ftplugin = 1
-let b:undo_ftplugin = 'setlocal foldmethod< comments< commentstring<'
+let b:undo_ftplugin = 'setlocal foldmethod< formatprg< comments< commentstring<'
 
 setl foldmethod=syntax
+setl formatprg=bean-format\ -c61
 setl comments=b:;
 setl commentstring=;%s
 compiler beancount
 
-" This variable customizes the behavior of the AlignCommodity command.
-if !exists('g:beancount_separator_col')
-    let g:beancount_separator_col = 50
-endif
 if !exists('g:beancount_account_completion')
     let g:beancount_account_completion = 'default'
 endif
@@ -21,9 +18,6 @@ if !exists('g:beancount_detailed_first')
     let g:beancount_detailed_first = 0
 endif
 
-command! -buffer -range AlignCommodity
-            \ :call beancount#align_commodity(<line1>, <line2>)
-
 command! -buffer -range GetContext
             \ :call beancount#get_context()
 
diff --git a/test/align.vader b/test/align.vader
deleted file mode 100644
index db6563e..0000000
--- a/test/align.vader
+++ /dev/null
@@ -1,45 +0,0 @@
-Given beancount:
-  2012-12-12 balance Assets:LongLongLongAccount 50.00
-  2012-12-12 balance Assets:Cash 50.00
-  2012-12-12 balance Assets:Cash -50.00
-  2012-12-12 balance Assets:Cash +50.00
-  2012-12-12 price EUR 50.00 USD
-      metadata: 50
-      Assets:Cash  50
-      Assets:Cash  50.00
-      ! Assets:Cash  50.00
-      Assets:Cash         50.00
-      Assets:Cash         50.00 USD
-
-Execute (align):
-  %AlignCommodity
-
-Expect beancount:
-  2012-12-12 balance Assets:LongLongLongAccount  50.00
-  2012-12-12 balance Assets:Cash                 50.00
-  2012-12-12 balance Assets:Cash                -50.00
-  2012-12-12 balance Assets:Cash                +50.00
-  2012-12-12 price EUR                           50.00 USD
-      metadata: 50
-      Assets:Cash                                50
-      Assets:Cash                                50.00
-      ! Assets:Cash                              50.00
-      Assets:Cash                                50.00
-      Assets:Cash                                50.00 USD
-
-Execute (change alignment column and align again):
-  let g:beancount_separator_col=40
-  %AlignCommodity
-
-Expect beancount:
-  2012-12-12 balance Assets:LongLongLongAccount 50.00
-  2012-12-12 balance Assets:Cash       50.00
-  2012-12-12 balance Assets:Cash      -50.00
-  2012-12-12 balance Assets:Cash      +50.00
-  2012-12-12 price EUR                 50.00 USD
-      metadata: 50
-      Assets:Cash                      50
-      Assets:Cash                      50.00
-      ! Assets:Cash                    50.00
-      Assets:Cash                      50.00
-      Assets:Cash                      50.00 USD