S0015: len expects one argument

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

Explanation

The len built-in has exactly one operand: the array whose element count should be read. Extra arguments leave the compiler with no defined interpretation, and missing arguments leave it without an array value.

Common causes

• calling len with no arguments
• calling len with multiple values instead of one array
• passing values separately when an array literal was intended

Canonical fixes

• pass one array value to len

Before:

count = len(a, b)

After:

count = len([a, b])

• remove extra arguments

Before:

count = len(items, fallback)

After:

count = len(items)

Code example

count = len(a, b)

Links

• RellC diagnostic overview