Maps vs Records: The Eternal Question

You might be wondering: “If records are just syntactic sugar over tuples, and we have maps, why use records at all?”

Excellent question. Here’s the philosophical breakdown:

Use Records When:

• You know all possible fields at compile time
• The structure is relatively small (< 20 fields)
• Performance matters (records are slightly faster than maps)
• You want compile-time field checking
• The fields are always atoms

Use Maps When:

• Fields are dynamic or unknown at compile time
• You need arbitrary keys (not just atoms)
• You’re working with JSON or external data
• You want more flexibility at the cost of less compile-time checking
• You’re building something where the data structure evolves frequently

Records are like strongly-typed structs. Maps are like flexible dictionaries. Choose according to your needs and tolerance for compiler complaints.