If the input is `Some` and non-empty after trimming, return it uppercased. Otherwise `None`. Solution highlights: - `map(str::trim)` transforms the i

A bunch of little string helpers. Notice how call sites read inside-out: `sparkle(&shout(s.trim()))`.

If the input is `Some` and not empty after trimming, return the uppercased trimmed text. Otherwise return `None`.

Return the words from `words` that are not in `dict`. The check is case-insensitive.

Does this string start with an uppercase letter? Solution highlights: - Take `&str` (read-only check, no need to own the string). - `chars().next()`

Does this string start with an uppercase letter?

Sum all `Some` values in the vector. Ignore `None` entries. Solution highlights: - `Option<T>` is an iterator of 0 or 1 element; `flatten` drops the

Sum all `Some` values in the vector. Ignore `None` entries.

Clean up a log line: trim, collapse internal whitespace, strip a leading `[INFO]` / `[WARN]` / `[ERROR]` tag. Solution highlights: - `trim()` replace

Clean up a log line by trimming whitespace, collapsing runs of internal whitespace, and removing a leading `[INFO]`, `[WARN]`, or `[ERROR]` tag.

Truncate a string to at most `max_bytes` bytes, respecting char boundaries. Solution highlights: - `is_char_boundary` lets us back up to the nearest

Truncate a string to at most `max_bytes` bytes.