Practical Guidelines

Here’s the accumulated wisdom for working with maps in LFE:

1. Use => for initial key creation, := for updates. This catches typos and signals intent.

2. Use maps for options when they’re mostly pairs. The maps:merge/2 pattern for defaults is elegant.

3. Use records for known, fixed structures where performance matters. Process loop state, for instance.

4. Pattern match freely. You needn’t match all keys—maps don’t mind selective attention.

5. Remember that maps are ordered. This makes their behavior predictable and their output deterministic.

6. Consider maps for any associative data unless you have specific reasons (like needing min/max operations frequently) to use something else.