environment method

@override Result<String?> environment(String name)

Looks up one process environment variable.

An absent variable is Ok(null), not a failure — absence is a normal answer, and only a host lookup fault is an error.

Implementation

@override
Result<String?> environment(String name) => _environmentResults.isNotEmpty
    ? _environmentResults.removeFirst()
    : Ok<String?>(environmentVariables[name]);