Field-with-value

Return a copy of a Field with a different value. This helper is the narrowest way to rewrite one field value while preserving the existing key.

Interface

pub fn Field::with_value(self : Field, value : String) -> Field {}

input

• self : Field - Base field whose value should be replaced.
• value : String - New value text for the returned field.

output

• Field - New field value carrying the updated value.

Explanation

Detailed rules explaining key parameters and behaviors

• This helper returns a new field value instead of mutating the original one.
• Only the value part is replaced.
• The original key is preserved exactly.
• This is useful for redaction, normalization, or tests that need one adjusted field value without rebuilding the key manually.

How to Use

Here are some specific examples provided.

When Need To Redact One Existing Field Value

When the field key should stay the same but the value should be hidden:

let user = field("user", "alice")
let redacted = user.with_value("***")

In this example, the returned field keeps the same key while changing only the visible value.

When Need To Rewrite A Field In Test Data

When one field should be adapted without reconstructing the key by hand:

let region = field("region", "cn").with_value("eu")

In this example, the helper keeps the transformation local to one field value.

Error Case

e.g.:

• If value is empty, the returned field is still valid and simply carries an empty string value.

• If the key should also change, constructing a new field with field(...) is clearer than chaining this helper.

Notes

1. Use this helper when the key should stay stable and only the value should change.

2. It is especially useful for redaction-style value updates in tests or adapters.