Question

Here s part of an overloaded protocol definition:

(defprotocol ClientProtocol
  (create-edge
    [this outV label inV] 
    [this outV label inV data])

And here s part of its implementation:

(ns bulbs.neo4jserver.client
  (:use [bulbs.base.client :only [ClientProtocol]]))

(deftype Neo4jClient [ns config]
  ClientProtocol

  (create-edge
    [this outV label inV data]
    (let [inV-uri (utils/normalize-uri (build-path neo4j-uri vertex-path inV))
          path (build-path vertex-path, outV, "relationships")
          params {:to inV-uri, :type label, :data (first data)}]
      (post config path params)))

  (create-edge
    [this outV label inV]
    ;; it doesn t like this call...
    (create-edge this outV label inV nil))

第二种方法试图将第一种方法称为:

java.lang.RuntimeException: Unable to resolve symbol: create-edge in this context

在我以第一种功能汇编后,我有两项定义,然后回过来,并增加了第二项。

但是,当我把议定书定义移入一个单独的档案并试图重新编造整件材料时,当第二种方法试图将第一种方法称为第一种方法时,就会犯错误,因为第一种方法尚未界定。

The Clojure reification docs have this comment:

If a method is overloaded in a protocol/interface, multiple independent method definitions must be supplied.

我假定这些定义不是independ<>/em>。

这样做的正确途径是什么?

Answer 1

你们的国名声明是错误的。

(ns bulbs.neo4jserver.client
  (:use [bulbs.base.client :only [ClientProtocol]]))

礼宾职能是正常的克隆功能,必须予以处理。因此,你必须将其列入<代码>:只有条款。

(ns bulbs.neo4jserver.client
  (:use [bulbs.base.client :only [create-edge ClientProtocol]]))

Answer 2

这里是一个 st倒的榜样,它用1.4.0英寸。

(ns hello.core)
(defprotocol ClientProtocol
 (create-edge
    [this outV label inV] 
    [this outV label inV data]))

(deftype Neo4jClient []
  ClientProtocol

 (create-edge
   [this outV label inV data]
    4)

  (create-edge
    [this outV label inV]
    (create-edge this outV label inV nil)))

hello.core> (create-edge (Neo4jClient.) 2 3 4)
4

hello.core> (create-edge (Neo4jClient.) 2 3 4 5)
4

这里是一个相互补救的例子(没有基例)。

(deftype Neo4jClient []
  ClientProtocol

  (create-edge
    [this outV label inV data]
    (println "OMG im in a looooooop...")
    (create-edge this 1 2 3))

  (create-edge
    [this outV label inV]
    (println "AHHH im in a looooooop...")
    (create-edge this 1 2 3 4)))


hello.core> (create-edge (Neo4jClient.) 1 2 3 4)
OMG im in a looooooop...
AHHH im in a looooooop...
OMG im in a looooooop...
AHHH im in a looooooop...
OMG im in a looooooop...
AHHH im in a looooooop...
OMG im in a looooooop...
AHHH im in a looooooop...

Answer 3

你在这里做的是罚款。

考虑这个例子:

(defprotocol ClientProtocol
  (create-edge
    [this outV label inV]
    [this outV label inV data]))

(deftype SampleClient []
  ClientProtocol

  (create-edge
    [this outV label inV]
      (create-edge this outV label inV {}))

  (create-edge
    [this outV label inV data]
      {:action :create-edge :this this :outV outV :label label :inV inV :data data}))

a. 正常运行时:

; => (create-edge (SampleClient.) 1 2 3)
{:action :create-edge, :this #<SampleClient user.SampleClient@63a2cc03>,
 :outV 1, :label 2, :inV 3, :data {}}
; => (create-edge (SampleClient.) 1 2 3 4)
{:action :create-edge, :this #<SampleClient user.SampleClient@7144c1a4>,
 :outV 1, :label 2, :inV 3, :data 4}

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