S0010: indexing requires an array

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

Explanation

Index expressions read an element from an array value. Scalars, tuples, records, enums, and non-array Shared[T] handles do not have array element storage, so they cannot be indexed.

Common causes

• indexing a scalar value such as Int, Bool, Char, or String
• using [] on a tuple instead of .N field access
• indexing a Shared[T] handle whose inner type is not an array

Canonical fixes

• index an array value

Before:

first = item[0]

After:

items = [item]
first = items[0]

• use tuple field access for tuple values

Before:

first = pair[0]

After:

first = pair.0

Code example

first = item[0]

Links

• RellC diagnostic overview