Простейшим является для использования clojure.walk/postwalk
. Я предполагаю, что вам не нужно беспокоиться о любых сочетаниях клавиш, таких как «удалить: я, только если это потомок: f».
Вот пример:
(ns tst.demo.core
(:use demo.core tupelo.core tupelo.test)
(:require [clojure.walk :as walk]))
(def data
{:a 1
:b 2
:c 3
:d [{:e 5}
{:f 6
:g {
:h 8
:i 9
:j 10}
:l [{
:m 11
:n 12
:p {:q 13
:r 14
:s 15
}}
{:m 16
:n 17
:p {:q 18
:r 19
:s 20
}}]}]})
(defn remove-keys [data keys]
(let [proc-node (fn [node]
(spyx node))
result (walk/postwalk proc-node data) ]
(spyx-pretty result)))
(def bad-keys #{:b :f :i :p :n})
(dotest
(remove-keys data bad-keys))
Показывает рекурсивную обработку postwalk
с выводом:
Testing tst.demo.core
node => :a
node => 1
node => [:a 1]
node => :b
node => 2
node => [:b 2]
node => :c
node => 3
node => [:c 3]
node => :d
node => :e
node => 5
node => [:e 5]
node => {:e 5}
node => :f
node => 6
node => [:f 6]
node => :g
node => :h
node => 8
node => [:h 8]
node => :i
node => 9
node => [:i 9]
node => :j
node => 10
node => [:j 10]
node => {:h 8, :i 9, :j 10}
node => [:g {:h 8, :i 9, :j 10}]
node => :l
node => :m
node => 11
node => [:m 11]
node => :n
node => 12
node => [:n 12]
node => :p
node => :q
node => 13
node => [:q 13]
node => :r
node => 14
node => [:r 14]
node => :s
node => 15
node => [:s 15]
node => {:q 13, :r 14, :s 15}
node => [:p {:q 13, :r 14, :s 15}]
node => {:m 11, :n 12, :p {:q 13, :r 14, :s 15}}
node => :m
node => 16
node => [:m 16]
node => :n
node => 17
node => [:n 17]
node => :p
node => :q
node => 18
node => [:q 18]
node => :r
node => 19
node => [:r 19]
node => :s
node => 20
node => [:s 20]
node => {:q 18, :r 19, :s 20}
node => [:p {:q 18, :r 19, :s 20}]
node => {:m 16, :n 17, :p {:q 18, :r 19, :s 20}}
node => [{:m 11, :n 12, :p {:q 13, :r 14, :s 15}} {:m 16, :n 17, :p {:q 18, :r 19, :s 20}}]
node => [:l [{:m 11, :n 12, :p {:q 13, :r 14, :s 15}} {:m 16, :n 17, :p {:q 18, :r 19, :s 20}}]]
node => {:f 6, :g {:h 8, :i 9, :j 10}, :l [{:m 11, :n 12, :p {:q 13, :r 14, :s 15}} {:m 16, :n 17, :p {:q 18, :r 19, :s 20}}]}
node => [{:e 5} {:f 6, :g {:h 8, :i 9, :j 10}, :l [{:m 11, :n 12, :p {:q 13, :r 14, :s 15}} {:m 16, :n 17, :p {:q 18, :r 19, :s 20}}]}]
node => [:d [{:e 5} {:f 6, :g {:h 8, :i 9, :j 10}, :l [{:m 11, :n 12, :p {:q 13, :r 14, :s 15}} {:m 16, :n 17, :p {:q 18, :r 19, :s 20}}]}]]
node => {:a 1, :b 2, :c 3, :d [{:e 5} {:f 6, :g {:h 8, :i 9, :j 10}, :l [{:m 11, :n 12, :p {:q 13, :r 14, :s 15}} {:m 16, :n 17, :p {:q 18, :r 19, :s 20}}]}]}
result =>
{:a 1,
:b 2,
:c 3,
:d
[{:e 5}
{:f 6,
:g {:h 8, :i 9, :j 10},
:l
[{:m 11, :n 12, :p {:q 13, :r 14, :s 15}}
{:m 16, :n 17, :p {:q 18, :r 19, :s 20}}]}]}
Вы можете видеть, что карты сначала превращаются в векторы пар ключ-значение, например [:n 17]
. Итак, когда вы получаете 2-vec, как это, просто посмотрите на первый элемент и верните nil
, если вам не нравится:
(defn len-2-vec? [node]
(and (sequential? node)
(= 2 (count node))))
(defn remove-keys [data bad-keys]
(let [proc-node (fn [node]
(if (and (len-2-vec? node)
(contains? bad-keys (first node)))
(do
(spyx :removed node)
nil)
node))
result (walk/postwalk proc-node data) ]
(spyx-pretty result)))
(def bad-keys #{:b :f :i :p :n})
(dotest
(remove-keys data bad-keys))
и вывод:
Testing tst.demo.core
:removed node => [:b 2]
:removed node => [:f 6]
:removed node => [:i 9]
:removed node => [:n 12]
:removed node => [:p {:q 13, :r 14, :s 15}]
:removed node => [:n 17]
:removed node => [:p {:q 18, :r 19, :s 20}]
(remove-keys data bad-keys) =>
{:a 1,
:c 3,
:d [{:e 5}
{:g {:h 8,
:j 10},
:l [{:m 11}
{:m 16}]}]}
Ran 2 tests containing 0 assertions.
0 failures, 0 errors.
Не забудьте Clojure CheatSheet .
Вот документ для spyx
.