GNU Info

(guile.info)Alist Key Equality

---

Next: Adding or Setting Alist Entries Up: Association Lists

---

Enter node , (file) or (file)node

Alist Key Equality
..................

All of Guile's dedicated association list procedures, apart from
`acons', come in three flavours, 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.