include the ledger grammar description

hledger.hs

@@ -138,6 +138,103 @@ type Account = String
 
 -- ledger file parsing
 -- struggling.. easier with a token parser ?
+-- here's the ledger 2.5 grammar:
+{-
+"The ledger file format is quite simple, but also very flexible. It supports many options,
+though typically the user can ignore most of them. They are summarized below.
+
+   The initial character of each line determines what the line means, and how it should be
+interpreted. Allowable initial characters are:
+
+NUMBER      A line beginning with a number denotes an entry. It may be followed by any
+            number of lines, each beginning with whitespace, to denote the entry’s account
+            transactions. The format of the first line is:
+
+                    DATE[=EDATE] [*|!] [(CODE)] DESC
+            If ‘*’ appears after the date (with optional effective date), it indicates the entry
+            is “cleared”, which can mean whatever the user wants it t omean. If ‘!’ appears
+            after the date, it indicates d the entry is “pending”; i.e., tentatively cleared from
+            the user’s point of view, but not yet actually cleared. If a ‘CODE’ appears in
+            parentheses, it may be used to indicate a check number, or the type of the
+            transaction. Following these is the payee, or a description of the transaction.
+            The format of each following transaction is:
+
+                      ACCOUNT     AMOUNT    [; NOTE]
+
+            The ‘ACCOUNT’ may be surrounded by parentheses if it is a virtual
+            transactions, or square brackets if it is a virtual transactions that must
+            balance. The ‘AMOUNT’ can be followed by a per-unit transaction cost,
+            by specifying ‘ AMOUNT’, or a complete transaction cost with ‘@ AMOUNT’.
+            Lastly, the ‘NOTE’ may specify an actual and/or effective date for the
+            transaction by using the syntax ‘[ACTUAL_DATE]’ or ‘[=EFFECTIVE_DATE]’ or
+            ‘[ACTUAL_DATE=EFFECtIVE_DATE]’.
+
+=           An automated entry. A value expression must appear after the equal sign.
+            After this initial line there should be a set of one or more transactions, just as
+            if it were normal entry. If the amounts of the transactions have no commodity,
+            they will be applied as modifiers to whichever real transaction is matched by
+            the value expression.
+ 
+~           A period entry. A period expression must appear after the tilde.
+            After this initial line there should be a set of one or more transactions, just as
+            if it were normal entry.
+
+
+!           A line beginning with an exclamation mark denotes a command directive. It
+            must be immediately followed by the command word. The supported commands
+            are:
+
+           ‘!include’
+                        Include the stated ledger file.
+           ‘!account’
+                        The account name is given is taken to be the parent of all transac-
+                        tions that follow, until ‘!end’ is seen.
+           ‘!end’       Ends an account block.
+ 
+;          A line beginning with a colon indicates a comment, and is ignored.
+ 
+Y          If a line begins with a capital Y, it denotes the year used for all subsequent
+           entries that give a date without a year. The year should appear immediately
+           after the Y, for example: ‘Y2004’. This is useful at the beginning of a file, to
+           specify the year for that file. If all entries specify a year, however, this command
+           has no effect.
+           
+ 
+P          Specifies a historical price for a commodity. These are usually found in a pricing
+           history file (see the ‘-Q’ option). The syntax is:
+
+                  P DATE SYMBOL PRICE
+
+N SYMBOL   Indicates that pricing information is to be ignored for a given symbol, nor will
+           quotes ever be downloaded for that symbol. Useful with a home currency, such
+           as the dollar ($). It is recommended that these pricing options be set in the price
+           database file, which defaults to ‘~/.pricedb’. The syntax for this command is:
+
+                  N SYMBOL
+
+        
+D AMOUNT   Specifies the default commodity to use, by specifying an amount in the expected
+           format. The entry command will use this commodity as the default when none
+           other can be determined. This command may be used multiple times, to set
+           the default flags for different commodities; whichever is seen last is used as the
+           default commodity. For example, to set US dollars as the default commodity,
+           while also setting the thousands flag and decimal flag for that commodity, use:
+
+                  D $1,000.00
+
+C AMOUNT1 = AMOUNT2
+           Specifies a commodity conversion, where the first amount is given to be equiv-
+           alent to the second amount. The first amount should use the decimal precision
+           desired during reporting:
+
+                  C 1.00 Kb = 1024 bytes
+
+i, o, b, h
+           These four relate to timeclock support, which permits ledger to read timelog
+           files. See the timeclock’s documentation for more info on the syntax of its
+           timelog files."
+-}
+
 
 ledgerLanguageDef = LanguageDef {
    commentStart   = ""