;'<<SPEC'

### `catch` ###

FIXME: We don't really need all of List for these tests, just `list`
and `literal`.

    -> Tests for functionality "Evaluate Robin Expression (with List)"

`catch` installs an exception handler.

If an exception is raised when evaluating the final argument of
`catch`, the exception value is bound to the symbol given as the
first argument of `catch`, and the second argument of `catch` is
evaluated in that new environment.

    | (catch error (list error #f)
    |   (raise (literal (nasty-value 999999))))
    = ((nasty-value 999999) #f)

If an exception is raised in the body of a macro that is applied
in the context of a `catch`, it will still be catched.

    | (bind errorful (macro (self args env) (raise (literal (nasty-value 1111))))
    |   (catch error (list error #f)
    |     (errorful joe)))
    = ((nasty-value 1111) #f)

If nothing is raised, `catch` will evaluate to whatever its body
evaluated to.

    | (catch error (list error #f) 42)
    = 42

The innermost `catch` will catch the exception.

    | (catch error (list error 5)
    |   (catch error (list error 9)
    |     (raise (literal derpy-value))))
    = (derpy-value 9)

An exception raised from within an exception handler is
caught by the next innermost exception handler.

    | (catch error (list error 5)
    |   (catch error (list error 9)
    |     (catch error (raise (list error error))
    |       (raise 7))))
    = ((7 7) 9)

`catch` expects its first argument to be a symbol.

    | (catch (3 4) (list error #f) 42)
    ? uncaught exception: (illegal-arguments ((3 4) (list error #f) 42))

`catch` expects exactly three arguments.

    | (catch error (list error #f))
    ? uncaught exception: (illegal-arguments (error (list error #f)))

    | (catch error (list error #f) 42 43)
    ? uncaught exception: (illegal-arguments (error (list error #f) 42 43))

'<<SPEC'

(require catch)