S0016: len expects an array

Generated from rellum-diagnostics/src/db.rs.

Explanation

The len built-in reports the element count of an array value. Scalars, records, enums, tuples, and function values do not carry the runtime array header that len reads, so they cannot be passed to len.

Common causes

• calling len on a String instead of an array
• calling len on a single value when an array was intended
• forgetting to wrap an item in brackets before measuring it

Canonical fixes

• pass an array value to len

Before:

count = len(item)

After:

count = len([item])

• if you need text length, convert or store text as the representation your program expects

Code example

count = len(item)

Links

• RellC diagnostic overview