Working with Lists in BAS

Whenever a bot handles “a bunch of things” — a set of links, parsed rows, a batch of values — it holds them in a list. The List module is the standard in-memory collection in BAS, with all the operations you’d expect from arrays in any language.

What a list is

A list is an ordered set of elements in one container. It lets you work with a collection of data, iterate over it, save it to a file and reload it, and repeatedly pass over its elements. Within a single thread, it’s where your working data lives.

The operations

Building and reading.

• Create list — start a new collection.
• Add element / Insert element — append, or place at a specific position.
• Get element / First element / Last element / Random element — read by position or pick one at random.
• Set element — overwrite the item at an index.

Removing.

• Delete by index / Delete by value — drop an item by position or by matching content.
• Clear list — empty it.

Querying.

• Count elements — how many items it holds.
• Search element / Get index — find an item and its position.

Transforming.

• Sort — order the elements.
• Reverse list — flip the order.
• Copy list — duplicate it.
• Combine lists — merge two lists into one.
• Compare lists — check whether two lists match.
• Join to string — flatten the list into a single string, e.g. comma-separated.

Lists vs resources

A list is the right tool for data inside one thread. The moment many threads need to pull from the same shared pool — a list of accounts split across 100 workers — switch to the Resources module, which handles distribution and the concurrency conflicts a plain list can’t. Rule of thumb: lists for local working data, resources for shared run input.