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2.29.1 Abstract

This SRFI defines basic hash tables. Hash tables are widely recognised as a fundamental data structure for a wide variety of applications. A hash table is a data structure that:

  1. Provides a mapping from some set of keys to some set of values associated to those keys.
  2. Has no intrinsic order for the (key, value) associations it contains.
  3. Supports in–place modification as the primary means of setting the contents of a hash table.
  4. Provides key lookup and destructive update in amortised constant time, provided that a good hash function is used.

This SRFI aims to accomplish these goals:

  1. To provide a consistent, generic and widely applicable API for hash tables.
  2. To improve code portability by providing a standard hash table facility with guaranteed behaviour.
  3. To help the programmer by defining utility routines that account for the most common situations of using hash tables.