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bubble-operator-upwards

This is a library by @HexstreamSoft. It contains a function for demultiplexing all alternative branches in a given form by producing a cartesian product.

Here is a short example:

POFTHEDAY> (bubble-operator-upwards:bubble-operator-upwards
            :or
            '(:or a (:or b c)))
(:OR A B C)

POFTHEDAY> (bubble-operator-upwards:bubble-operator-upwards
            :or
            '(:and a (:or b c)))
(:OR (:AND A B) (:AND A C))

POFTHEDAY> (bubble-operator-upwards:bubble-operator-upwards
            :or
            '(:or a (:and b c)))
(:OR A (:AND B C))

POFTHEDAY> (bubble-operator-upwards:bubble-operator-upwards
            :or
            '(:and
              (:or a b)
              (:or c d)))
(:OR (:AND A C) (:AND A D) (:AND B C) (:AND B D))

Do you remember what is capable Lass from my previous post?

It provides a shorthand form for writing complex CSS selectors:

POFTHEDAY> (lass:compile-and-write
            '((:and
               (:or article section)
               (:= data-author (:or yukari ran chen))
               (:nth-child (:or 1 2 3)))
              :display none))

"article[data-author=\"yukari\"]:nth-child(1),
article[data-author=\"yukari\"]:nth-child(2),
article[data-author=\"yukari\"]:nth-child(3),
article[data-author=\"ran\"]:nth-child(1),
article[data-author=\"ran\"]:nth-child(2),
article[data-author=\"ran\"]:nth-child(3),
article[data-author=\"chen\"]:nth-child(1),
article[data-author=\"chen\"]:nth-child(2),
article[data-author=\"chen\"]:nth-child(3),
section[data-author=\"yukari\"]:nth-child(1),
section[data-author=\"yukari\"]:nth-child(2),
section[data-author=\"yukari\"]:nth-child(3),
section[data-author=\"ran\"]:nth-child(1),
section[data-author=\"ran\"]:nth-child(2),
section[data-author=\"ran\"]:nth-child(3),
section[data-author=\"chen\"]:nth-child(1),
section[data-author=\"chen\"]:nth-child(2),
section[data-author=\"chen\"]:nth-child(3){
    display: none;
}"

It is crazy, but with “bubble-operator-upwards” you can get the same behavior in one call:

POFTHEDAY> (bubble-operator-upwards:bubble-operator-upwards
            :or
            '((:or article section)
              (:= data-author (:or yukari ran chen))
              (:nth-child (:or 1 2 3))))
(:OR (ARTICLE (:= DATA-AUTHOR YUKARI) (:NTH-CHILD 1))
 (ARTICLE (:= DATA-AUTHOR YUKARI) (:NTH-CHILD 2))
 (ARTICLE (:= DATA-AUTHOR YUKARI) (:NTH-CHILD 3))
 (ARTICLE (:= DATA-AUTHOR RAN) (:NTH-CHILD 1))
 (ARTICLE (:= DATA-AUTHOR RAN) (:NTH-CHILD 2))
 (ARTICLE (:= DATA-AUTHOR RAN) (:NTH-CHILD 3))
 (ARTICLE (:= DATA-AUTHOR CHEN) (:NTH-CHILD 1))
 (ARTICLE (:= DATA-AUTHOR CHEN) (:NTH-CHILD 2))
 (ARTICLE (:= DATA-AUTHOR CHEN) (:NTH-CHILD 3))
 (SECTION (:= DATA-AUTHOR YUKARI) (:NTH-CHILD 1))
 (SECTION (:= DATA-AUTHOR YUKARI) (:NTH-CHILD 2))
 (SECTION (:= DATA-AUTHOR YUKARI) (:NTH-CHILD 3))
 (SECTION (:= DATA-AUTHOR RAN) (:NTH-CHILD 1))
 (SECTION (:= DATA-AUTHOR RAN) (:NTH-CHILD 2))
 (SECTION (:= DATA-AUTHOR RAN) (:NTH-CHILD 3))
 (SECTION (:= DATA-AUTHOR CHEN) (:NTH-CHILD 1))
 (SECTION (:= DATA-AUTHOR CHEN) (:NTH-CHILD 2))
 (SECTION (:= DATA-AUTHOR CHEN) (:NTH-CHILD 3)))

What does it mean?

If you want to implement similar shorthand syntax in your DSL, you don’t have to implement it yourself. Use “bubble-operator-upwards”.