1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
open Core
type account_type = Asset | Equity | Liability | Expense | Income
type tx_type =
| Interest_tx
| Online_banking_tx
| Recurrent_direct_tx
| Payment_terminal_tx
| Cash_payment_tx
| Atm_tx
| Auto_save_rounding_tx
| Batch_tx
| Direct_debit_tx
| Periodic_tx
type iban_tag = Account_tag | Counterparty_iban_tag [@@deriving compare]
type unit_tag = Filed_tag | GooglePay_tag | AutoRoundSavings_tag
[@@deriving compare]
type string_tag =
| Desc_tag
| User_tag
| Counterparty_name_tag
| Reference_tag
| Mandate_id_tag
| Creditor_id_tag
| Other_party_tag
| Transaction_tag
| Terminal_tag
| Card_seq_no_tag
| Savings_account_tag
[@@deriving compare]
module Label = struct
type 'a t =
| Iban_label : iban_tag -> Iban.t t
| String_label : string_tag -> string t
| Timestamp_label : Time_ns.t t
| Unit_label : unit_tag -> unit t
let int_to_cmp x : ('a, 'a) Dmap.cmp =
if x < 0 then Lt else if x > 0 then Gt else Eq
let compare (type a1 a2) (v1 : a1 t) (v2 : a2 t) : (a1, a2) Dmap.cmp =
match (v1, v2) with
| Iban_label t1, Iban_label t2 -> int_to_cmp @@ [%compare: iban_tag] t1 t2
| String_label t1, String_label t2 ->
int_to_cmp @@ [%compare: string_tag] t1 t2
| Timestamp_label, Timestamp_label -> Eq
| Unit_label t1, Unit_label t2 -> int_to_cmp @@ [%compare: unit_tag] t1 t2
| Iban_label _, _ -> Lt
| String_label _, Iban_label _ -> Gt
| String_label _, _ -> Lt
| Timestamp_label, Unit_label _ -> Lt
| Timestamp_label, _ -> Gt
| Unit_label _, _ -> Gt
end
module Labels = Dmap.Make (Label)
module Money : sig
type t
val equal : t -> t -> bool
val compare : t -> t -> int
val of_z : Z.t -> t
val to_z : t -> Z.t
val ( + ) : t -> t -> t
val ( - ) : t -> t -> t
end = struct
type t = Z.t
let equal = Z.equal
let compare = Z.compare
let of_z = Fn.id
let to_z = Fn.id
let ( + ) x y = Z.(x + y)
let ( - ) x y = Z.(x - y)
end
type scalar = Amount of Money.t | Rate of Z.t [@@deriving equal, compare]
type account_id = string list
type commodity_id = string (* TODO: consider making this UUID *)
type account = {
id : account_id;
description : string list;
commodity_id : commodity_id;
balance : Money.t;
}
type bal_assert = { account : account_id; amount : Money.t; labels : Labels.t }
module Account_id_key = struct
type t = account_id
type comparator_witness
end
module Tx : sig
type t
type error = Unbalanced
val make :
cleared:Date.t option ->
commodity_id:commodity_id ->
debit:scalar Map.M(Account_id_key).t ->
credit:scalar Map.M(Account_id_key).t ->
labels:Labels.t ->
(t, error) result
val cleared : t -> Date.t option
val commodity_id : t -> commodity_id
val debit : t -> scalar Map.M(Account_id_key).t
val credit : t -> scalar Map.M(Account_id_key).t
val labels : t -> Labels.t
end = struct
(* We hide this because we only want to allow constructing balanced transactions *)
type t = {
cleared : Date.t option;
commodity_id : commodity_id;
debit : scalar Map.M(Account_id_key).t;
credit : scalar Map.M(Account_id_key).t;
labels : Labels.t;
}
[@@deriving fields]
type error = Unbalanced
(* TODO: check if debits and credits are balanced *)
let is_balanced _debits _credits = true
let make ~cleared ~commodity_id ~debit ~credit ~labels =
if not (is_balanced debit credit) then Error Unbalanced
else Ok { cleared; commodity_id; debit; credit; labels }
end
type item = Tx_item of Tx.t | Bal_assert_item of bal_assert
type ledger = Ledger of item list
|
