From daee48271519ed7f9fca8b02a828ae19793abc15 Mon Sep 17 00:00:00 2001 From: Justin Ethier Date: Thu, 29 Sep 2016 18:55:20 -0400 Subject: [PATCH] Fixup description --- docs/api/srfi/69.md | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/docs/api/srfi/69.md b/docs/api/srfi/69.md index a67a30d2..07b9eda3 100644 --- a/docs/api/srfi/69.md +++ b/docs/api/srfi/69.md @@ -2,7 +2,12 @@ The `(srfi 69)` library defines basic hash tables. -Like an ordinary `and`, an `and-let*` special form evaluates its arguments -- expressions -- one after another in order, till the first one that yields `#f`. Unlike `and`, however, a non-#f result of one expression can be bound to a fresh variable and used in the subsequent expressions. `and-let*` is a cross-breed between `let*` and `and`. +Hash tables are widely recognised as a fundamental data structure for a wide variety of applications. A hash table is a data structure that: + +- provides a mapping from some set of keys to some set of values associated to those keys +- has no intrinsic order for the (key, value) associations it contains +- supports in-place modification as the primary means of setting the contents of a hash table +- provides key lookup and destructive update in amortised constant time, provided that a good hash function is used See the [SRFI document](http://srfi.schemers.org/srfi-69/srfi-69.html) for more information.