Add --pivot option with tests and docs (#323)

hledger/Hledger/Cli/CliOptions.hs

@@ -115,6 +115,7 @@ inputflags = [
  ,flagReq ["rules-file"]  (\s opts -> Right $ setopt "rules-file" s opts) "RFILE" "CSV conversion rules file (default: FILE.rules)"
  ,flagReq ["alias"]  (\s opts -> Right $ setopt "alias" s opts)  "OLD=NEW" "display accounts named OLD as NEW"
  ,flagNone ["ignore-assertions"] (setboolopt "ignore-assertions") "ignore any balance assertions in the journal"
+ ,flagReq ["pivot"]  (\s opts -> Right $ setopt "pivot" s opts)  "TAG" "Replace the accounts of postings with TAG by TAG:<value>"
  ]
 
 -- | Common report-related flags: --period, --cost, etc.

hledger/Hledger/Cli/Utils.hs

@@ -71,7 +71,24 @@ withJournalDo opts cmd = do
   rulespath <- rulesFilePathFromOpts opts
   journalpaths <- journalFilePathFromOpts opts
   ej <- readJournalFiles Nothing rulespath (not $ ignore_assertions_ opts) journalpaths
-  either error' (cmd opts . journalApplyAliases (aliasesFromOpts opts)) ej
+  either error' (cmd opts . pivotByOpts opts . journalApplyAliases (aliasesFromOpts opts)) ej
+
+-- | Apply the pivot transformation on a journal, if option is present.
+pivotByOpts :: CliOpts -> Journal -> Journal
+pivotByOpts opts
+  | Just tag <- maybeTag = pivot tag
+  | Nothing  <- maybeTag = id
+ where maybeTag = maybestringopt "pivot" . rawopts_ $ opts
+
+-- | Apply the pivot transformation by given tag on a journal.
+pivot :: String -> Journal -> Journal
+pivot tag j = j{jtxns = map pivotTrans . jtxns $ j}
+ where
+  pivotTrans t = t{tpostings = map pivotPosting . tpostings $ t}
+  pivotPosting p
+    | Just (_ , value) <- tagTuple = p{paccount = joinAccountNames tag value}
+    | _                <- tagTuple = p
+   where tagTuple = find ((tag ==) . fst) . ptags $ p
 
 -- | Write some output to stdout or to a file selected by --output-file.
 writeOutput :: CliOpts -> String -> IO ()

hledger/doc/examples.m4.md

@@ -65,3 +65,19 @@ $ hledger print desc:shop                 # show transactions with shop in the d
 $ hledger activity -W                     # show transaction counts per week as a bar chart
 ```
 
+With the journal
+
+```journal
+2016/02/16 Member Fee Payment John Doe
+    assets:bank account                                   2 EUR
+    income:member fees                                  -2 EUR
+      ; member: John Doe
+```
+
+the --pivot comand will output the following:
+
+```shells
+$ hledger bal --pivot member
+    2 EUR  assets:bank account
+   -2 EUR  member:John Doe
+```

hledger/doc/options.m4.md

@@ -104,6 +104,10 @@ Both of these must be written after the command name.
 `-B --cost                    `
 : show amounts in their cost price's commodity
 
+`--pivot TAG
+: will transform the journal before any other processing by replacing the account name of every posting having the tag TAG with content VALUE by the  account name "TAG:VALUE".
+: The TAG will only match if it is a full-length match. The pivot will only happen if the TAG is on a posting, not if it is on the transaction. If the tag value is a multi:level:account:name the new account name will be "TAG:multi:level:account:name".
+
 ## Multiple files
 
 One may specify the `--file FILE` option multiple times. This is equivalent to

tests/misc/pivot.test

@@ -0,0 +1,40 @@
+# --pivot tests
+
+# check pivot with print
+hledger -f- --pivot TAG print
+<<<
+2016/02/16 Test Transaction
+    Account1                                   2 EUR
+    Account2                                  -2 EUR
+    ; TAG: value
+>>>
+2016/02/16 Test Transaction
+    Account1          2 EUR
+    TAG:value        -2 EUR
+    ; TAG: value
+
+>>>=0
+
+# check pivot with bal
+hledger -f- --pivot member bal --no-total
+<<<
+2016/02/16 Member Fee Payment John Doe
+    assets:bank account                                   2 EUR
+    income:member fees                                  -2 EUR
+      ; member: John Doe
+>>>
+               2 EUR  assets:bank account
+              -2 EUR  member:John Doe
+>>>=0
+
+# check with another example
+hledger -f- --pivot budget bal --no-total
+<<<
+2016/02/16 Donation Freifunk
+    assets:bank account                                   2 EUR
+    income:donations                                  -2 EUR
+      ; budget: Freifunk
+>>>
+               2 EUR  assets:bank account
+              -2 EUR  budget:Freifunk
+>>>=0