1 files changed, 23 insertions, 11 deletions

diff --git a/bank-eiffel/account.e b/bank-eiffel/account.e
index 39e4167..61145f0 100644
--- a/bank-eiffel/account.e
+++ b/bank-eiffel/account.e
@@ -62,14 +62,14 @@ feature {NONE} -- Initialization
                         a_credit_line_range.count() = 2
                         an_interest_debit_range.count() = 2
                         an_interest_deposit_range.count() = 2
-                        a_credit_line_range.item (0) < a_credit_line_range.item (1)
-                        an_interest_debit_range.item (0) < an_interest_debit_range.item (1)
-                        an_interest_deposit_range.item (0) < an_interest_deposit_range.item (1)
+                        a_credit_line_range.item (1) < a_credit_line_range.item (2)
+                        an_interest_debit_range.item (1) < an_interest_debit_range.item (2)
+                        an_interest_deposit_range.item (1) < an_interest_deposit_range.item (2)
                 do
                         create authorized_signers.make(1)
                         add_authorized_signer (an_authorized_signer)
-                        transfer_minamount := 2
-                        balance := 0
+                        transfer_minamount := 2.0
+                        balance := 0.0
                         creditline := a_credit_line
                         interest_debit := an_interest_debit
                         interest_deposit := an_interest_deposit
@@ -139,7 +139,6 @@ feature -- Basic operations
                         Result := authorized_signers.has (an_authorized_signer)
                 end
 
-
         authorized_signers_count : INTEGER
                 do
                         Result := authorized_signers.count
@@ -150,6 +149,19 @@ feature -- Basic operations
                         Result := transfer_minamount
                 end
 
+        get_balance : REAL_64
+                do
+                        Result := balance
+                end
+
+        advance
+                do
+                        if balance < 0.0 then -- debit
+                                balance := balance + (balance * interest_debit)
+                        else -- deposit
+                                balance := balance + (balance * interest_deposit)
+                        end
+                end
 
 feature {NONE} -- Implementation
 
@@ -191,13 +203,13 @@ feature {NONE} -- Implementation
 
 invariant
         interest_debit_within_bounds:
-                interest_debit >= interest_debit_range.item (0) and
-                interest_debit <= interest_debit_range.item (1)
+                interest_debit >= interest_debit_range.item (1) and
+                interest_debit <= interest_debit_range.item (2)
         interest_deposit_within_bounds:
-                interest_deposit >= interest_deposit_range.item (0) and
-                interest_deposit <= interest_deposit_range.item (1)
+                interest_deposit >= interest_deposit_range.item (1) and
+                interest_deposit <= interest_deposit_range.item (2)
         authorized_signers_attached: authorized_signers /= Void
         authorized_signers_not_empty: authorized_signers.count > 0
         transfer_minamount_positive: transfer_minamount > 0.0
-        creditline_range_correct: creditline >= creditline_range.item (0) and creditline <= creditline_range.item (1)
+        creditline_range_correct: creditline >= creditline_range.item (1) and creditline <= creditline_range.item (2)
 end