在Scala中解析命令行参数的最佳方法是什么? 我个人更喜欢一些不需要外部罐子的轻量级的东西。
相关:
我如何解析Java中的命令行参数? c++有哪些参数解析器库? 在c#中解析命令行参数的最佳方法
在Scala中解析命令行参数的最佳方法是什么? 我个人更喜欢一些不需要外部罐子的轻量级的东西。
相关:
我如何解析Java中的命令行参数? c++有哪些参数解析器库? 在c#中解析命令行参数的最佳方法
当前回答
斯科普特/斯科普特
val parser = new scopt.OptionParser[Config]("scopt") {
head("scopt", "3.x")
opt[Int]('f', "foo") action { (x, c) =>
c.copy(foo = x) } text("foo is an integer property")
opt[File]('o', "out") required() valueName("<file>") action { (x, c) =>
c.copy(out = x) } text("out is a required file property")
opt[(String, Int)]("max") action { case ((k, v), c) =>
c.copy(libName = k, maxCount = v) } validate { x =>
if (x._2 > 0) success
else failure("Value <max> must be >0")
} keyValueName("<libname>", "<max>") text("maximum count for <libname>")
opt[Unit]("verbose") action { (_, c) =>
c.copy(verbose = true) } text("verbose is a flag")
note("some notes.\n")
help("help") text("prints this usage text")
arg[File]("<file>...") unbounded() optional() action { (x, c) =>
c.copy(files = c.files :+ x) } text("optional unbounded args")
cmd("update") action { (_, c) =>
c.copy(mode = "update") } text("update is a command.") children(
opt[Unit]("not-keepalive") abbr("nk") action { (_, c) =>
c.copy(keepalive = false) } text("disable keepalive"),
opt[Boolean]("xyz") action { (x, c) =>
c.copy(xyz = x) } text("xyz is a boolean property")
)
}
// parser.parse returns Option[C]
parser.parse(args, Config()) map { config =>
// do stuff
} getOrElse {
// arguments are bad, usage message will have been displayed
}
上面生成了以下用法文本:
scopt 3.x
Usage: scopt [update] [options] [<file>...]
-f <value> | --foo <value>
foo is an integer property
-o <file> | --out <file>
out is a required file property
--max:<libname>=<max>
maximum count for <libname>
--verbose
verbose is a flag
some notes.
--help
prints this usage text
<file>...
optional unbounded args
Command: update
update is a command.
-nk | --not-keepalive
disable keepalive
--xyz <value>
xyz is a boolean property
这是我目前使用的。使用干净,没有太多包袱。 (免责声明:我现在维护这个项目)
其他回答
这在很大程度上是我对同一主题的Java问题的答案的无耻克隆。事实证明,JewelCLI是scala友好的,因为它不需要JavaBean样式的方法来获得自动参数命名。
JewelCLI是一个scala友好的Java库,用于命令行解析,生成干净的代码。它使用带有注解的代理接口来动态地为命令行参数构建类型安全的API。
一个参数接口Person.scala的例子:
import uk.co.flamingpenguin.jewel.cli.Option
trait Person {
@Option def name: String
@Option def times: Int
}
参数接口Hello.scala的用法示例:
import uk.co.flamingpenguin.jewel.cli.CliFactory.parseArguments
import uk.co.flamingpenguin.jewel.cli.ArgumentValidationException
object Hello {
def main(args: Array[String]) {
try {
val person = parseArguments(classOf[Person], args:_*)
for (i <- 1 to (person times))
println("Hello " + (person name))
} catch {
case e: ArgumentValidationException => println(e getMessage)
}
}
}
将上述文件的副本保存到一个目录中,并将JewelCLI 0.6 JAR下载到该目录中。
在Linux/Mac OS X/etc / Bash中编译并运行示例:
scalac -cp jewelcli-0.6.jar:. Person.scala Hello.scala
scala -cp jewelcli-0.6.jar:. Hello --name="John Doe" --times=3
在Windows命令提示符中编译并运行示例:
scalac -cp jewelcli-0.6.jar;. Person.scala Hello.scala
scala -cp jewelcli-0.6.jar;. Hello --name="John Doe" --times=3
运行该示例应该产生以下输出:
Hello John Doe
Hello John Doe
Hello John Doe
我喜欢这段代码的简洁外观…从这里的讨论中收集到: http://www.scala-lang.org/old/node/4380
object ArgParser {
val usage = """
Usage: parser [-v] [-f file] [-s sopt] ...
Where: -v Run verbosely
-f F Set input file to F
-s S Set Show option to S
"""
var filename: String = ""
var showme: String = ""
var debug: Boolean = false
val unknown = "(^-[^\\s])".r
val pf: PartialFunction[List[String], List[String]] = {
case "-v" :: tail => debug = true; tail
case "-f" :: (arg: String) :: tail => filename = arg; tail
case "-s" :: (arg: String) :: tail => showme = arg; tail
case unknown(bad) :: tail => die("unknown argument " + bad + "\n" + usage)
}
def main(args: Array[String]) {
// if there are required args:
if (args.length == 0) die()
val arglist = args.toList
val remainingopts = parseArgs(arglist,pf)
println("debug=" + debug)
println("showme=" + showme)
println("filename=" + filename)
println("remainingopts=" + remainingopts)
}
def parseArgs(args: List[String], pf: PartialFunction[List[String], List[String]]): List[String] = args match {
case Nil => Nil
case _ => if (pf isDefinedAt args) parseArgs(pf(args),pf) else args.head :: parseArgs(args.tail,pf)
}
def die(msg: String = usage) = {
println(msg)
sys.exit(1)
}
}
Here's a scala command line parser that is easy to use. It automatically formats help text, and it converts switch arguments to your desired type. Both short POSIX, and long GNU style switches are supported. Supports switches with required arguments, optional arguments, and multiple value arguments. You can even specify the finite list of acceptable values for a particular switch. Long switch names can be abbreviated on the command line for convenience. Similar to the option parser in the Ruby standard library.
我刚刚在scalac的scala.tools.cmd包中找到了一个广泛的命令行解析库。
参见http://www.assembla.com/code/scala-eclipse-toolchain/git/nodes/src/compiler/scala/tools/cmd?rev=f59940622e32384b1e08939effd24e924a8ba8db
freecli
package freecli
package examples
package command
import java.io.File
import freecli.core.all._
import freecli.config.all._
import freecli.command.all._
object Git extends App {
case class CommitConfig(all: Boolean, message: String)
val commitCommand =
cmd("commit") {
takesG[CommitConfig] {
O.help --"help" ::
flag --"all" -'a' -~ des("Add changes from all known files") ::
O.string -'m' -~ req -~ des("Commit message")
} ::
runs[CommitConfig] { config =>
if (config.all) {
println(s"Commited all ${config.message}!")
} else {
println(s"Commited ${config.message}!")
}
}
}
val rmCommand =
cmd("rm") {
takesG[File] {
O.help --"help" ::
file -~ des("File to remove from git")
} ::
runs[File] { f =>
println(s"Removed file ${f.getAbsolutePath} from git")
}
}
val remoteCommand =
cmd("remote") {
takes(O.help --"help") ::
cmd("add") {
takesT {
O.help --"help" ::
string -~ des("Remote name") ::
string -~ des("Remote url")
} ::
runs[(String, String)] {
case (s, u) => println(s"Remote $s $u added")
}
} ::
cmd("rm") {
takesG[String] {
O.help --"help" ::
string -~ des("Remote name")
} ::
runs[String] { s =>
println(s"Remote $s removed")
}
}
}
val git =
cmd("git", des("Version control system")) {
takes(help --"help" :: version --"version" -~ value("v1.0")) ::
commitCommand ::
rmCommand ::
remoteCommand
}
val res = runCommandOrFail(git)(args).run
}
这将产生以下用法:
使用