- mapping-pop mapping failureprocedure
- mapping-pop mappingprocedure
The mapping-pop procedure exported from (srfi 146) chooses the association with the least key from mapping and returns three values, a newly allocated mapping that uses the same comparator as mapping and contains all associations of mapping except the chosen one, and the key and the value of the chosen association. If mapping contains no association and failure is supplied, then failure is invoked in tail context on no arguments and its values returned. Otherwise, it is an error.
The hashmap-pop procedure exported by (srfi 146 hash) is similar but chooses an arbitrary association.