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Source for wiki AssociationListsCowan version 1

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cowan

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74.68.121.27

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AssociationListsCowan

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This proposal is a tiny extension to SRFI 1 to bring it to parity with Common Lisp.

== Association lists ==

`(make-alist `''keys values''`)`

Returns a newly allocated alist whose pairs are constructed from the elements of the lists ''keys'' and ''values''.  (Common Lisp PAIRLIS.)

`(reverse-assq `''obj alist''`)`

`(reverse-assv `''obj alist''`)`

`(reverse-assoc `''obj alist'' [ ''compare'' ] `)`

These procedures find the ﬁrst pair in ''alist'' whose cdr (rather than car) field is ''obj'' , and returns that pair. If no pair in ''alist'' has ''obj'' as its cdr, then `#f` (not the empty list) is returned. The `assq` procedure uses `eq?` to compare obj with the cdr fields of the pairs in ''alist'', while `assv` uses `eqv?` and `assoc` uses ''compare'' if given and `equal?` otherwise.  (Common Lisp RASSOC.)

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2012-12-24 08:41:55