std.env - Environment Utilities

std.env exposes fallible access to the process environment.

All operations use EnvError for failures. EnvError.kind is the typed env.EnvErrorKind enum with Invalid, NotUnicode, and Os variants; compare or match those variants directly rather than searching display text. detail contains the diagnostic and key contains the affected variable name when available. Use error.message() for the detail or error.to_string() for a decorated display string. EnvError.from_message(text) creates an environment error when adapting an application-level failure to an environment boundary.

env.get(string key) -> result<optional<string>, EnvError> - returns ok(none) only when the variable does not exist; invalid names and non-Unicode values are errors.
env.set(string key, string value) -> result<void, EnvError> - sets a process environment variable; invalid names are reported.
env.remove(string key) -> result<void, EnvError> - removes a variable (including a missing variable) idempotently.
env.contains(string key) -> result<bool, EnvError> - checks for a variable and reports values that are not valid UTF-8.
env.entries() -> result<list<tuple<string, string>>, EnvError> - returns all entries sorted by key; invalid Unicode is an error.

Example:

Mux