Warning: This is the manual of the legacy Guile 2.0 series. You may want to read the manual of the current stable series instead.
Next: Removing Alist Entries, Previous: Adding or Setting Alist Entries, Up: Association Lists [Contents][Index]
assq
, assv
and assoc
find the entry in an alist
for a given key, and return the (key . value)
pair.
assq-ref
, assv-ref
and assoc-ref
do a similar
lookup, but return just the value.
Return the first entry in alist with the given key. The
return is the pair (KEY . VALUE)
from alist. If there’s
no matching entry the return is #f
.
assq
compares keys with eq?
, assv
uses
eqv?
and assoc
uses equal?
. See also SRFI-1
which has an extended assoc
(SRFI-1 Association Lists).
Return the value from the first entry in alist with the given
key, or #f
if there’s no such entry.
assq-ref
compares keys with eq?
, assv-ref
uses
eqv?
and assoc-ref
uses equal?
.
Notice these functions have the key argument last, like other
-ref
functions, but this is opposite to what assq
etc above use.
When the return is #f
it can be either key not found, or
an entry which happens to have value #f
in the cdr
. Use
assq
etc above if you need to differentiate these cases.
Next: Removing Alist Entries, Previous: Adding or Setting Alist Entries, Up: Association Lists [Contents][Index]