NETSCRIPT: Rework script ram updates (#408)

src/types.ts

@@ -1,3 +1,12 @@
+// The object properties on these numeric types are for typechecking only and do not exist at runtime. They're just a way to require a typechecking function.
+export type Integer = number & { __Integer: true };
+export type PositiveNumber = number & { __Positive: true };
+export type PositiveInteger = Integer & PositiveNumber;
+
+// Numeric typechecking functions
+export const isInteger = (n: unknown): n is Integer => Number.isInteger(n);
+export const isPositiveInteger = (n: unknown): n is PositiveInteger => isInteger(n) && n > 0;
+
 /** Status object for functions that return a boolean indicating success/failure
  * and an optional message */
 export interface IReturnStatus {