Estimated hours taken: 2
Branches: main
Add the operation transform_value to map, tree234 and rbtree. This applies a
higher order argument to a value in the map. Often a value needs to be updated
using its previous value. Currently this requires two lookups of the key.
With transform_value only one lookup is required.
NEWS
Mention the new predicate.
library/map.m
library/rbtree.m
library/tree234.m
Add transform_value.
library/require.m
Add a version of report_lookup_error that doesn't take a value
argument, since the value argument is not available in transform_value.
tests/hard_coded/Mmakefile
tests/hard_coded/transform_value.exp
tests/hard_coded/transform_value.m
Test transform_value.
