我正在寻找类似join
的东西,但是分隔符放在每个字符串的前面,而不仅仅是充当分隔符。
作为一个简单的例子,我正在寻找一个不太丑陋的版本:
(def params [1 2 3 4])
(clojure.string/join (for [x params] (str "¶m=" x)))
结果
"¶m=1¶m=2¶m=3¶m=4"
答案 0 :(得分:4)
不带分隔符的呼叫(clojure.string/join coll)
与(apply str coll)
一样,这是一个小小的胜利:
(apply str (for [x params] (str "¶m=" x)))
那么您可能更喜欢map
,而不是for
:
(apply str (map #(str "¶m=" %) params))
interleave
可以工作:
(apply str (interleave (repeat "¶m=") params))
您可以将其重构为分隔前缀,并使用以下字符串interleave
:
(apply str
(interleave (repeat \&)
(map #(str "param=" %) params)))
您可能喜欢穿线的外观:
(->> (map #(str "param=" %) params)
(interleave (repeat \&))
(apply str))
您可以提取一个函数来更一般地执行此操作:
(defn prepend-join [separator & cs]
(apply str (apply interleave (repeat separator) cs)))
(prefix-join \& (map #(str "param=" %) params))
答案 1 :(得分:3)
,此外:
clojure的核心库中有一个方便的函数,即apply plugin: 'com.android.library'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-kapt'
apply plugin: 'kotlin-android-extensions'
android {
compileSdkVersion 28
buildToolsVersion "28.0.3"
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
defaultConfig {
minSdkVersion 23
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
consumerProguardFiles 'consumer-rules.pro'
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
debug {
shrinkResources false
minifyEnabled true
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
externalNativeBuild {
cmake {
path file('CMakeLists.txt')
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
testImplementation 'junit:junit:4.12'
implementation 'com.google.android.material:material:1.0.0'
implementation 'com.jakewharton:butterknife:10.0.0'
annotationProcessor 'com.jakewharton:butterknife-compiler:10.0.0'
implementation 'androidx.core:core-ktx:1.0.2'
androidTestImplementation 'androidx.test:runner:1.1.0'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0'
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
implementation 'io.reactivex.rxjava2:rxandroid:2.1.0'
implementation 'io.reactivex.rxjava2:rxjava:2.2.0'
kapt "com.jakewharton:butterknife-compiler:10.0.0"
kapt 'androidx.databinding:databinding-compiler:3.5.0'
implementation project(':openCVLibrary345')
}
clojure.pprint/cl-format
谈论它的功能,它只是冰山一角
答案 2 :(得分:2)
在params
前面加上一个空字符串对我来说似乎很干净:
(clojure.string/join "¶m=" (cons "" params))
;;=> "¶m=1¶m=2¶m=3¶m=4"