Simplified the functor

Author: debasishg

lib/model/trade.ml

@@ -6,9 +6,10 @@ open CalendarLib
 open Market
 open Validator
 open List
+open Taxfee
 
-module Trade(T : Trade_sig) : Trade_sig with module TaxFeeForTrade = T.TaxFeeForTrade = struct
-  module TaxFeeForTrade = T.TaxFeeForTrade 
+module Trade(TaxFeeForMarket: TaxFee) : Trade_sig = struct
+  module TaxFeeForTrade = TaxFeeForMarket
 
   type money = float
 
@@ -32,6 +33,8 @@ module Trade(T : Trade_sig) : Trade_sig with module TaxFeeForTrade = T.TaxFeeFor
   let net_amount t: money = 
     principal t +. (List.fold_left (fun acc (_, v) -> acc +. v) 0. t.tax_fees)
 
+  let tax_fees t = t.tax_fees
+
   let value_as t tax_fee = 
     let tax_fee_rate = List.assoc tax_fee TaxFeeForTrade.tax_fee_rates in
     tax_fee_rate *. (principal t) 

lib/model/trade_sig.ml

@@ -11,6 +11,7 @@ module type Trade_sig = sig
   type t
   type money
 
+  (* create a validated trade *)
   val create_trade: 
     account_no: Accountno.t 
     -> isin: ISINCode.t 
@@ -21,10 +22,15 @@ module type Trade_sig = sig
     -> trade_date: Calendar.t 
     -> value_date: Calendar.t option -> (t, string) validator_result
 
+  (* decorate a trade with tax/fees and net amount *)
   val with_tax_fees: t -> t
 
+  (* get the principal amount of the trade *)
   val principal: t -> money
 
+  (* get the net amount of the trade *)
   val net_amount: t -> money
+
+  val tax_fees: t -> (TaxFeeForTrade.t * money) list
 
 end