A set of useful transformations, wrapping the excellent Specter library to do some things I need to do a lot, which Specter doesn't trivially support.
These transformations operate at different levels, but all make use of a recursive descent into the data structure to apply a transformation throughout to either keys or values in nested structures. In ascending order of abstraction:
These are Specter paths which can be used in regular Specter expressions.
user> (doc morph.core/RECURSIVE-MAPS)
-------------------------
morph.core/RECURSIVE-MAPS
A Specter path for recursively selecting all the maps in a deeply
nested structure.
nil
user> (doc morph.core/RECURSIVE-MAP-KEYS)
-------------------------
morph.core/RECURSIVE-MAP-KEYS
A Specter path for recursively selecting all the map keys in a deeply
nested structure.
nil
user> (doc morph.core/RECURSIVE-MAP-VALS)
-------------------------
morph.core/RECURSIVE-MAP-VALS
A Specter path for recursively selecting all the map values in a
deeply nested structure. This matches maps in non-map collections, but not
values in non-map collections.
nil
Higher order recursive descent transformations:
user> (doc morph.core/transform-vals)
-------------------------
morph.core/transform-vals
([pred f coll] [f coll])
Transform values in all nested structures recursively. The `coll`
argument may be a collection or a map. Values are filtered using the
`pred` function, which must take a single argument and return
truthy. If selected, keys are transformed using the `f` function,
which must take a single argument and return the replacement value.
Example:
user> (->> {:str "some string" :vec [1 1 1 1] :top-level-number 8}
(morph.core/transform-vals number? inc)
(morph.core/transform-vals string? clojure.string/upper-case))
{:str "SOME STRING", :vec [2 2 2 2], :top-level-number 9}
nil
user> (doc morph.core/transform-keys)
-------------------------
morph.core/transform-keys
([pred f mappings coll] [pred f coll] [f coll])
Transform keys in all nested structures recursively. The `coll`
argument may be a collection or a map. Keys are filtered using the
`pred` function, which must take a single argument and return
truthy. If selected, keys are transformed using the `f` function,
which must take a single argument and return the replacement value.
A `mappings` map argument may be provided, which will used to rename
keys once the `f` transformation is complete.
Examples:
user> (morph.core/transform-keys
keyword
(comp keyword clojure.string/upper-case name)
{:str "some string" :vec [1 1 1 1] :top-level-number 8})
{:STR "some string", :VEC [1 1 1 1], :TOP-LEVEL-NUMBER 8}
user> (morph.core/transform-keys
keyword
(comp keyword clojure.string/upper-case name)
{:STR :charArray}
{:str "some string" :vec [1 1 1 1] :top-level-number 8})
{:charArray "some string", :VEC [1 1 1 1], :TOP-LEVEL-NUMBER 8}
user>
nil
user>
Finally some common tasks, which use the transform-keys and transform-vals methods to do specifically useful things:
user> (doc morph.core/dates->joda)
-------------------------
morph.core/dates->joda
([coll])
Transform all the java.util.Date objects in an arbitrarily nested
structure into org.joda.time.DateTime objects.
nil
user> (doc morph.core/joda->dates)
-------------------------
morph.core/joda->dates
([coll])
Transform all the org.joda.time.DateTime objects in an arbitrarily
nested structure into java.util.Date objects.
nil
user>
and some which are so blindingly obvious I couldn't think of any documentation which wasn't just the function names:
user> (morph.core/keys->snake_case
{:dog :cat :thing [1 2 3] :foo {:bar-doof 9 :antEater false :one_snake true :StringBuffer :lol}})
{:dog :cat,
:thing [1 2 3],
:foo {:bar_doof 9, :ant_eater false, :one_snake true, :string_buffer :lol}}
user> (morph.core/keys->camelCase
{:dog :cat :thing [1 2 3] :foo {:bar-doof 9 :antEater false :one_snake true :StringBuffer :lol}})
{:dog :cat,
:thing [1 2 3],
:foo {:barDoof 9, :antEater false, :oneSnake true, :stringBuffer :lol}}
user> (morph.core/keys->PascalCase
{:dog :cat :thing [1 2 3] :foo {:bar-doof 9 :antEater false :one_snake true :StringBuffer :lol}})
{:Dog :cat,
:Thing [1 2 3],
:Foo {:BarDoof 9, :AntEater false, :OneSnake true, :StringBuffer :lol}}
user> (morph.core/keys->kebab-case
{:dog :cat :thing [1 2 3] :foo {:bar-doof 9 :antEater false :one_snake true :StringBuffer :lol}})
{:dog :cat,
:thing [1 2 3],
:foo {:bar-doof 9, :ant-eater false, :one-snake true, :string-buffer :lol}}
user> Copyright © 2018,2019 Jonathan Irving, Paul Lam and others.
Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.