(define-environment clause ...)
clause = name-id | [name-id maybe-type option ...] maybe-type =
| : type-id option = #:name env-var-name-expr | #:default default-expr
Each name-id is assigned the value of the environment variable with the name env-var-name-expr. If no env-var-name-expr is provided, the environment variable name is inferred based on name-id: the identifier is converted to all caps, all dashes are converted to underscores, and all question marks are stripped.
Before being assigned to name-id, the value of the environment variable is parsed based on type-id. If no type-id is provided, the type is inferred to be String. The following types are supported:
Boolean (must be either "true" or "false")
If the specified variable does not exist in the environment, name-id is set to the value of default-expr. If no default-expr is provided, an error is raised.
(define/provide-environment clause ...)
(define-environment-variable name-id maybe-type option ...)