Alist Key Equality

All of Guile’s dedicated association list procedures, apart from acons, come in three flavors, depending on the level of equality that is required to decide whether an existing key in the association list is the same as the key that the procedure call uses to identify the required entry.

• Procedures with assq in their name use eq? to determine key equality.
• Procedures with assv in their name use eqv? to determine key equality.
• Procedures with assoc in their name use equal? to determine key equality.

acons is an exception because it is used to build association lists which do not require their entries’ keys to be unique.