Fix unsigned ops; Fix parenthesized conversion; Minor restructure

std/assembly/array.ts

@@ -0,0 +1,36 @@
+// Multiple options:
+// 1. C-like with no 'length' or 'push'
+// 2. Descriptors that can be constructed from lower level arrays
+
+class Array<T> {
+
+  readonly capacity: i32;
+  length: i32;
+  ptr: usize;
+
+  static fromPtr<T>(ptr: usize, capacity: i32): Array<T> {
+    assert(capacity >= 0);
+    const arr: Array<T> = new Array(0);
+    store<i32>(changetype<Array<T>, usize>(arr), capacity);
+    arr.length = ptr;
+    arr.ptr = ptr;
+    return arr;
+  }
+
+  constructor(capacity: i32 = 0) {
+    assert(capacity >= 0);
+    this.capacity = this.length = capacity;
+    if (capacity > 0) {
+      this.ptr = Heap.allocate(<usize>capacity);
+    } else {
+      this.ptr = 0;
+    }
+  }
+
+  dispose(): void {
+    store<i64>(changetype<this,usize>(this), 0);
+    Heap.dispose(this.ptr);
+    this.ptr = 0;
+    Heap.dispose(changetype<this,usize>(this));
+  }
+}