Major Section: PROGRAMMING
Example: (er-progn (check-good-foo-p (f-get-global 'my-foo state) state) (value (* (f-get-global 'my-foo state) (f-get-global 'bar state))))
This sequencing primitive is only useful when programming with state, something that very few users will probably want to do. See state.
Er-progn is used much the way that
progn is used in Common
Lisp, except that it expects each form within it to evaluate to an
``error triple'' of the form
(mv erp val state). The first such
form, if any, that evaluates to such a triple where
erp is not
nil yields the error triple returned by the
there is no such form, then the last form returns the value of the
We intend to write more about this topic, especially if there are
requests to do so.