implement includes

Author: querolita

src/lib/provable/dynamic-array.ts

@@ -511,6 +511,20 @@ class DynamicArrayBase<ProvableValue = any, Value = any> {
     }
   }
 
+  /**
+   * Checks whether the dynamic array includes a value.
+   * 
+   * @param value 
+   * @returns
+   */
+  includes(value: ProvableValue): Bool {
+    let type = this.innerType;
+    let isIncluded = this.array.map((t) => Provable.equal(this.innerType, t, value));
+    let isSome = isIncluded.reduce((acc, curr) => acc.or(curr), new Bool(false));
+    return isSome;
+  }
+
+
   // cached variables to not duplicate constraints if we do something like
   // array.get(i), array.set(i, ..) on the same index
   #indexMasks: Map<Field, Bool[]> = new Map();

src/lib/provable/test/dynamic-array.unit-test.ts

@@ -312,6 +312,10 @@ import { Provable } from '../provable.js';
   expectThrows(() => {
     bytes.insert(new Field(4), new UInt8(5));
   }, 'Cannot insert out-of-bounds');
+
+  // Checking inclusion of elements
+  assert(bytes.includes(new UInt8(1)).toBoolean());
+  assert(bytes.includes(new UInt8(20)).not().toBoolean());
 }
 
 // Using dynamic arrays as private input
@@ -561,6 +565,10 @@ await Provable.runAndCheck(() => {
           for (let i = 0; i < 8; i++) {
             assert(bytes.get(new Field(i)).value.equals(new Field(i + 1)));
           }
+
+          // Checking inclusion of elements
+          assert(bytes.includes(new UInt8(1)).toBoolean());
+          assert(bytes.includes(new UInt8(20)).not().toBoolean());
         },
       },
     },