implement the compact array

wewei · Sep 18, 2024 · 23b32a1 · 23b32a1
1 parent cc72920
commit 23b32a1
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Showing 2 changed files with 80 additions and 6 deletions.
diff --git a/packages/@ot-doc/document/src/lib/array-document.spec.ts b/packages/@ot-doc/document/src/lib/array-document.spec.ts
@@ -1,5 +1,5 @@
 import { describeDocumentMeta, DocumentTestCases } from "../util/test-utility";
-import { arrayDocument, deleteAt, insertAt, ArrayOplet } from "./array-document";
+import { arrayDocument, deleteAt, insertAt, ArrayOplet, compact } from "./array-document";
 
 const arrNum = arrayDocument<number>();
 
@@ -48,4 +48,34 @@ describeDocumentMeta('arrayDocument<number>', arrNum, {
     // const b_a = comp(b)(a);
     // console.log(JSON.stringify(b_a));
   },
-} as DocumentTestCases<ArrayOplet<number>[]>);
+} as DocumentTestCases<ArrayOplet<number>[]>);
+
+
+const compactArrayNum = compact(arrNum);
+describeDocumentMeta('CompactArrayOp<number>', compactArrayNum, {
+  singleton: [
+    {},
+    {
+      ins: [
+        { idx: 0, arr: [1, 2, 3] },
+        { idx: 3, arr: [4, 5] },
+      ],
+    },
+    {
+      del: [
+        { idx: 3, arr: [4, 5] },
+        { idx: 0, arr: [1, 2, 3] },
+      ],
+    },
+    {
+      del: [
+        { idx: 3, arr: [4, 5] },
+        { idx: 0, arr: [1, 2, 3] },
+      ],
+      ins: [
+        { idx: 0, arr: [5, 4, 3] },
+        { idx: 3, arr: [2, 1] },
+      ],
+    },
+  ],
+});
diff --git a/packages/@ot-doc/document/src/lib/array-document.ts b/packages/@ot-doc/document/src/lib/array-document.ts
@@ -185,12 +185,56 @@ export function compact<T>(meta: DocumentMeta<ArrayOp<T>>): DocumentMeta<Compact
     }, {} as CompactArrayOp<T>);
   }
 
+  function decompress(op: CompactArrayOp<T>): ArrayOp<T> | undefined {
+    return meta.comp(
+      (op.del ?? []).reduce((m, { idx, arr }) => {
+        m.concat(
+          arr
+            .map((val, i): ArrayOplet<T> => ({ typ: 'del', val, idx: idx + i }))
+            .reverse()
+        );
+        return m;
+      }, [] as ArrayOp<T>)
+    )(
+      (op.ins ?? []).reduce((m, { idx, arr }) => {
+        m.concat(
+          arr.map(
+            (val, i): ArrayOplet<T> => ({ typ: 'ins', val, idx: idx + i })
+          )
+        );
+        return m;
+      }, [] as ArrayOp<T>)
+    );
+  }
+
 
   return {
     idn: {},
-    inv: () => {},
-    comp: () => () => {},
-    tran: () => () => {},
-    equ: () => () => {},
+    inv: ({ ins, del }) => {
+      const r: CompactArrayOp<T> = {};
+      if (ins) {
+        r.del = [...ins].reverse();
+      }
+      if (del) {
+        r.ins = [...del].reverse();
+      }
+      return r;
+    },
+    comp: (a) => (b) => {
+      const dcA = decompress(a);
+      const dcB = decompress(b);
+      if (!dcA || !dcB) return undefined;
+      const dcC = meta.comp(dcA)(dcB);
+      if (!dcC) return undefined;
+      return compress(dcC);
+    },
+    tran: (a) => (/* b */) => a, // TODO
+    equ: (a) => (b) => {
+      if (a === b) return true;
+      const dcA = decompress(a);
+      const dcB = decompress(b);
+      if (dcA && dcB) return meta.equ(dcA)(dcB);
+      return dcA === dcB; // Iff both are undefined
+    },
   };
 };