Shape specifiers for :g-bindings, more flexible than auto-bindings.
The flex-bindings function lets you create somewhat more
complicated shape-specs than is possible with auto-bindings. We
assume familiarity with auto-bindings in this documentation. The
specific feature flex-bindings offers that auto-bindings does not is the
ability to split an integer variable into segments and generate indices for
each segment independently.
:g-bindings (flex-bindings ; expands to:
;; auto-bindings list -- generates indices
((:int a1 10)
(:rev (:mix (:int a2 13)
(:int b1 13)))
(:int b2 10))
:arrange ;; generate shape spec bindings from the indices
((:int a a1 a2) ;; a is a g-integer, indices are a1's appended to a2's
(:int b b1 b2))))
The first argument is just a list of auto-bindings (though the syntax
differs trivially in that flex-bindings takes them in a single argument whereas
auto-bindings uses &rest args). They are used to generate indices,
but not the actual g-bindings. We generate from these a mapping from each
variable name to its list of indices.
The :arrange argument, if provided, must be a list consisting of the
following sorts of forms:
- (:int a b c ...) means generate an integer shape-spec binding for
variable a, consisting of the appended indices of b, c, etc.,
from the auto-bindings form.
- (:int a) means generate an integer shape-spec binding for variable
a using the indices of a from the auto-bindings form.
- (:bool a) means generate a Boolean binding for variable a,
using the index of a from the auto-bindings form.
- (:bool a b) means generate a Boolean binding for variable a,
using the index of b from the auto-bindings form.
If the :arrange argument is not provided, flex-bindings acts
just like auto-bindings -- it generates an entry for each variable
mentioned in the auto-bindings.