Add account identifiers.

.github/workflows/src.yml

@@ -0,0 +1,15 @@
+on:
+  push:
+    paths:
+      - 'src/**'
+jobs:
+  src:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: aviate-labs/[email protected]
+        with:
+          dfx-version: 0.8.0
+          install-moc: true
+          vessel-version: 0.6.2
+      - run: for i in src/*.mo ; do moc $(vessel sources) --check $i ; done

.github/workflows/test.yml

@@ -1,4 +1,7 @@
-on: push
+on:
+  push:
+    paths:
+      - 'test/**'
 jobs:
   test:
     runs-on: ubuntu-latest
@@ -8,4 +11,7 @@ jobs:
         with:
           dfx-version: 0.8.0
           install-moc: true
-      - run: for i in test/*.mo ; do moc --package base $(dfx cache show)/base -r $i ; done
+          vessel-version: 0.6.2
+      - run: |
+          cd test
+          for i in *.mo ; do moc $(vessel sources) -r $i ; done

.gitignore

@@ -0,0 +1 @@
+.vessel/

package-set.dhall

@@ -0,0 +1,17 @@
+let upstream = https://github.com/dfinity/vessel-package-set/releases/download/mo-0.6.7-20210818/package-set.dhall sha256:c4bd3b9ffaf6b48d21841545306d9f69b57e79ce3b1ac5e1f63b068ca4f89957
+let Package = { name : Text, version : Text, repo : Text, dependencies : List Text }
+
+let additions = [
+  { name = "sha"
+  , repo = "https://github.com/aviate-labs/sha.mo"
+  , version = "v0.1.1"
+  , dependencies = ["base", "encoding"]
+  },
+  { name = "encoding"
+  , repo = "https://github.com/aviate-labs/encoding.mo"
+  , version = "v0.2.1"
+  , dependencies = ["base"]
+  }
+] : List Package
+
+in  upstream # additions

src/AccountIdentifier.mo

@@ -0,0 +1,33 @@
+import Array "mo:base/Array";
+import Binary "mo:encoding/Binary";
+import Blob "mo:base/Blob";
+import Hex "mo:encoding/Hex";
+import Principal "mo:base/Principal";
+import SHA256 "mo:sha/SHA256";
+
+import CRC32 "CRC32";
+
+module {
+    public type AccountIdentifier = Text;
+    public type SubAccount        = [Nat8];
+
+    private let prefix : [Nat8] = [10, 97, 99, 99, 111, 117, 110, 116, 45, 105, 100];
+
+    public func fromPrincipal(p : Principal, subAccount : ?SubAccount) : AccountIdentifier {
+        fromBlob(Principal.toBlob(p), subAccount);
+    };
+
+    public func fromBlob(data : Blob, subAccount : ?SubAccount) : AccountIdentifier {
+        fromArray(Blob.toArray(data), subAccount);
+    };
+
+    public func fromArray(data : [Nat8], subAccount : ?SubAccount) : AccountIdentifier {
+        let account : [Nat8] = switch (subAccount) {
+            case (null) { Array.freeze(Array.init<Nat8>(32, 0)); };
+            case (?sa)  { sa; };
+        };
+        let hash = SHA256.sum224(Array.flatten<Nat8>([prefix, data, account]));
+        let crc  = CRC32.checksum(hash);
+        Hex.encode(Array.append<Nat8>(Binary.BigEndian.fromNat32(crc), hash));
+    };
+};

test/AccountIdentifier.mo

@@ -0,0 +1,7 @@
+import Debug "mo:base/Debug";
+import Principal "mo:base/Principal";
+
+import AccountIdentifier "../src/AccountIdentifier";
+
+let p = Principal.fromText("g42pg-k3n7u-4sals-ufza4-34yrp-mmvkt-psecp-7do7x-snvq4-llwrj-2ae");
+assert(AccountIdentifier.fromPrincipal(p, null) == "A7218DB708C35689495871C3C6860504503AB2A545630809DD8609130331B0C2");

test/CRC32.mo

@@ -0,0 +1,9 @@
+import Blob "mo:base/Blob";
+import Text "mo:base/Text";
+
+import CRC32 "../src/CRC32";
+
+import Debug "mo:base/Debug";
+
+assert(CRC32.checksum([171,205,1]) == 591393286);
+assert(CRC32.checksum(Blob.toArray(Text.encodeUtf8("The quick brown fox jumps over the lazy dog"))) == 1095738169);

vessel.dhall

@@ -0,0 +1,4 @@
+{
+  dependencies = [ "base", "sha", "encoding" ],
+  compiler = None Text
+}