TRIVIAL-WITH

TRIVIAL-WITH is a simple library designed to contain multiple levels of WITH- invocations into a single WITH:- form.

There are many Lisp idioms prefixed with WITH-. By containing an environment (and often hiding the cleanup code) they make Lisp a great language. However, having a lot of nested WITH- forms is a visual nuisance.

with:all is implemented as a macro that expands into nested WITH-xxx forms. Because it expands syntactically, you may use it with any Lisp macro that starts with the characters "WITH-".

(with:all
  ((open-file (in "my-file"))
   (slots (x y) rect)
   (foreign-slots ...
   ...)
 ...
)

NOTES

WITH- forms that return a value

Most with- style macros create an environment in the contained body of code. There are exceptions such as with-output-to-string, which by default returns a string. Placed inside a with:all macro the string would be lost (unless it (with-output-to-string..) form was the first one in the list.

TRIVIAL-WITH can capture the return value of a (WITH-xxx) by setting the value of a symbol that precedes the form by using `(with:side-effect var ...)

(with:all
  ((open-file (in "my-file"))
   (slots (x y) rect)
   (side-effect z (output-to-string (x))
   ...
  )
  ...
  )

The above will basically expand to (setf z (with-output-to-string...)) The variable z of course must be in scope for this to work.