Clojure

Supplied-p parameter in clojure

Details

  • Type: Enhancement Enhancement
  • Status: Open Open
  • Priority: Minor Minor
  • Resolution: Unresolved
  • Affects Version/s: Release 1.7
  • Fix Version/s: None
  • Component/s: None
  • Labels:
  • Environment:
    Mac OSX 10.9.4

    java version "1.7.0_17"
    Java(TM) SE Runtime Environment (build 1.7.0_17-b02)
    Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)
  • Patch:
    Code and Test

Description

As see in https://groups.google.com/forum/?hl=en#!topic/clojure/jWc51JOkvsA

I think we can add a ? option for destructure ,then we can write a test like :

(deftest supplied-p-in-destructuring
  (let [{:keys [a b c d] :p? {a a-p? b b-p? c c-p? d d-p?} :or {a 1}} {:b 2 :c 3 }]
    (is (= a 1))
    (is (false? a-p?))
    (is (= 2 b))
    (is (true? b-p?))
    (is (= 3 c))
    (is (true? c-p?))
    (is (nil? d))
    (is (false? d-p?))))

Even if the a var has a default value 1 by :or option,but the a-p? is still false.
Just like the supplied-p-parameter in Commons LISP.

The patch is attached with code and test.

Activity

Hide
Steve Miner added a comment -

As mentioned on the mailing list, you could use {:as arg} destructuring to get same information. Here's a slightly modified example that works in the current Clojure:

(deftest supplied-p-in-destructuring
  ;; (let [{:keys [a b c d] :p? {a a-p? b b-p? c c-p? d d-p?} :or {a 1}} {:b 2 :c 3 }]
  (let [{:keys [a b c d] :or {a 1} :as argmap} {:b 2 :c 3 }
        supplied? (partial contains? argmap)
        a-p? (supplied? :a)
        b-p? (supplied? :b)
        c-p? (supplied? :c)
        d-p? (supplied? :d)]
    (is (= a 1))
    (is (false? a-p?))
    (is (= 2 b))
    (is (true? b-p?))
    (is (= 3 c))
    (is (true? c-p?))
    (is (nil? d))
    (is (false? d-p?))))
Show
Steve Miner added a comment - As mentioned on the mailing list, you could use {:as arg} destructuring to get same information. Here's a slightly modified example that works in the current Clojure:
(deftest supplied-p-in-destructuring
  ;; (let [{:keys [a b c d] :p? {a a-p? b b-p? c c-p? d d-p?} :or {a 1}} {:b 2 :c 3 }]
  (let [{:keys [a b c d] :or {a 1} :as argmap} {:b 2 :c 3 }
        supplied? (partial contains? argmap)
        a-p? (supplied? :a)
        b-p? (supplied? :b)
        c-p? (supplied? :c)
        d-p? (supplied? :d)]
    (is (= a 1))
    (is (false? a-p?))
    (is (= 2 b))
    (is (true? b-p?))
    (is (= 3 c))
    (is (true? c-p?))
    (is (nil? d))
    (is (false? d-p?))))

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Dates

  • Created:
    Updated: