dvlopt.void
Macros and functions for handling nil under various circumstances.
Macros and functions for handling nil under various circumstances.
altcljmacro
(alt)(alt x)(alt x & xs)Selects the first non-nil value.
Being a macro, arguments are not evaluated until needed.
Ex. (alt nil false 42) => false
Selects the first non-nil value.
Being a macro, arguments are not evaluated until needed.
Ex. (alt nil
false
42)
=> falseassocclj
(assoc hmap k v)(assoc hmap k v & kvs)Behaves like standard assoc but associates v only if it is not nil.
Behaves like standard `assoc` but associates `v` only if it is not nil.
assoc-inclj
(assoc-in hmap path v)Behaves like standard assoc-in but associates v only if it is not nil.
Behaves like standard `assoc-in` but associates `v` only if it is not nil.
assoc-strictclj
(assoc-strict hmap k v)(assoc-strict hmap k v & kvs)If v is nil, not only is it not associated, the involved key is actually removed from the map.
If `v` is nil, not only is it not associated, the involved key is actually removed from the map.
callcljmacro
(call f & args)Calls f with the given arguments only if f is not nil.
Being a macro, the arguments are not evaluated if there are not needed.
Calls `f` with the given arguments only if `f` is not nil. Being a macro, the arguments are not evaluated if there are not needed.
dissoc-inclj
(dissoc-in hmap path)Deep dissoc, natural counterpart of Clojure's assoc-in.
It is recursive, meaning that if dissociating a key results in an empty map, that map is itself removed from its parent (provided it is of course nested).
Eg. (dissoc-in {:a {:b 42} :c :ok} [:a :b])
=> {:c :ok}
Deep dissoc, natural counterpart of Clojure's `assoc-in`.
It is recursive, meaning that if dissociating a key results in an empty map, that map is itself removed from its
parent (provided it is of course nested).
Eg. (dissoc-in {:a {:b 42}
:c :ok}
[:a :b])
=> {:c :ok}dmergeclj
(dmerge & hmaps)Deep merges the given maps.
Merging a key pointing to nil results in that key being dissociated. Similarly to dissoc-in, empty maps are recursively
removed.
Eg. (dmerge {:a {:b 42}} {:a {:b nil} :c 42})
=> {:c 42}
Deep merges the given maps.
Merging a key pointing to nil results in that key being dissociated. Similarly to `dissoc-in`, empty maps are recursively
removed.
Eg. (dmerge {:a {:b 42}}
{:a {:b nil}
:c 42})
=> {:c 42}dmerge-withclj
(dmerge-with f & hmaps)Is to dmerge what this namespace's version of merge-with is to merge.
Is to `dmerge` what this namespace's version of `merge-with` is to `merge`.
dmerge-with*clj
(dmerge-with* f hmaps)(dmerge-with* f hmap-1 hmap-2)Like dmerge-with, but maps are provided in a collection.
Like `dmerge-with`, but maps are provided in a collection.
mergeclj
(merge & hmaps)Just like standard merge, but a key pointing to nil in the right map means it must be dissociated.
Eg. (merge {:a 42 :b 42} {:b nil :c 42})
=> {:a 42
:c 42}
Just like standard `merge`, but a key pointing to nil in the right map means it must be dissociated.
Eg. (merge {:a 42
:b 42}
{:b nil
:c 42})
=> {:a 42
:c 42}merge-withclj
(merge-with f & hmaps)Just like standard 'merge-with' but behaves like this namespace's version of merge: a key pointing to a nil value in a
right map means it will be dissociated. The same applies when f returns nil.
Just like standard 'merge-with' but behaves like this namespace's version of `merge`: a key pointing to a nil value in a right map means it will be dissociated. The same applies when `f` returns nil.
merge-with*clj
(merge-with* f hmaps)Just like this namespace's version of merge-with but maps are provided in a collection.
Just like this namespace's version of `merge-with` but maps are provided in a collection.
no-opclj
(no-op)(no-op _)(no-op _ _)(no-op _ _ _)(no-op _ _ _ _)(no-op _ _ _ _ _)(no-op _ _ _ _ _ _)(no-op _ _ _ _ _ _ _)(no-op _ _ _ _ _ _ _ _)(no-op _ _ _ _ _ _ _ _ & _)Does absolutely nothing, but efficiently.
Does absolutely nothing, but efficiently.
pruneclj
(prune node)If node is a map, keys with nil values will be removed. In case of nested maps, the process is recursive.
If node is a map, keys with nil values will be removed. In case of nested maps, the process is recursive.
updateclj
(update hmap k f)(update hmap k f a)(update hmap k f a b)(update hmap k f a b c)(update hmap k f a b c & more)Just like standard update but returning a nil value results in the involved key being dissociated.
Just like standard `update` but returning a nil value results in the involved key being dissociated.
update-inclj
(update-in hmap path f & args)Just like standard update-in but once again, returning nil results in the involved key being dissociated.
Similarly to dissoc-in, empty maps are then recursively removed as well.
When an empty path is provided, nothing happens.
Just like standard `update-in` but once again, returning nil results in the involved key being dissociated. Similarly to `dissoc-in`, empty maps are then recursively removed as well. When an empty path is provided, nothing happens.
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