2

哈斯凯尔弗雷格你好世界：

你好.fr：

module Hello where

main args = do
    putStrLn "Hello, World!"

此代码生成 hello.java ：

/*
  Source code is in UTF-8 encoding. The following symbols may appear, among others:
  α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ ς σ τ υ φ χ ψ ω « • ¦ » ∀ ∃ ∷ … → ← fi fl ƒ
  If you can't read this, you're out of luck. This code was generated with the frege compiler version 3.24.80
  from hello.fr Do not edit this file! Instead, edit the source file and recompile.
*/

import frege.run8.Func;
import frege.run8.Lazy;
import frege.run8.Thunk;
import frege.run.Kind;
import frege.run.RunTM;
import frege.runtime.Meta;
import frege.runtime.Phantom.RealWorld;
import frege.Prelude;
import frege.control.Category;
import frege.control.Semigroupoid;
import frege.java.IO;
import frege.java.Lang;
import frege.java.Util;
import frege.java.util.Regex;
import frege.prelude.Maybe;
import frege.prelude.PreludeArrays;
import frege.prelude.PreludeBase;
import frege.prelude.PreludeIO;
import frege.prelude.PreludeList;
import frege.prelude.PreludeMonad;
import frege.prelude.PreludeText;

@SuppressWarnings("unused")
@Meta.FregePackage(
  source="hello.fr", time=1470398249962L, jmajor=1, jminor=8,
  imps={
    "frege.Prelude", "frege.prelude.PreludeArrays", "frege.prelude.PreludeBase", "frege.prelude.PreludeIO",
    "frege.prelude.PreludeList", "frege.prelude.PreludeMonad", "frege.prelude.PreludeText", "frege.java.util.Regex"
  },
  nmss={"Prelude", "PreludeArrays", "PreludeBase", "PreludeIO", "PreludeList", "PreludeMonad", "PreludeText", "Regexp"},
  symas={}, symcs={}, symis={}, symts={},
  symvs={@Meta.SymV(offset=20, name=@Meta.QName(pack="Hello", base="main"), stri="s(u)", sig=1, depth=1, rkind=49)},
  symls={},
  taus={
    @Meta.Tau(kind=2, suba=0, tcon={@Meta.QName(kind=0, pack="frege.prelude.PreludeBase", base="[]")}),
    @Meta.Tau(kind=2, suba=0, tcon={@Meta.QName(kind=0, pack="frege.prelude.PreludeBase", base="StringJ")}),
    @Meta.Tau(kind=2, suba=0, tcon={@Meta.QName(kind=0, pack="frege.prelude.PreludeBase", base="Char")}),
    @Meta.Tau(kind=0, suba=1, subb=2), @Meta.Tau(kind=0, suba=0, subb=3),
    @Meta.Tau(kind=2, suba=0, tcon={@Meta.QName(kind=0, pack="frege.prelude.PreludeBase", base="ST")}),
    @Meta.Tau(kind=2, suba=0, tcon={@Meta.QName(kind=0, pack="frege.prelude.PreludeBase", base="RealWorld")}),
    @Meta.Tau(kind=0, suba=5, subb=6),
    @Meta.Tau(kind=2, suba=0, tcon={@Meta.QName(kind=0, pack="frege.prelude.PreludeBase", base="()")}),
    @Meta.Tau(kind=0, suba=7, subb=8)
  },
  rhos={@Meta.Rho(rhofun=false, rhotau=4), @Meta.Rho(rhofun=false, rhotau=9), @Meta.Rho(sigma=0, rhotau=1)},
  sigmas={@Meta.Sigma(rho=0), @Meta.Sigma(rho=2)}, exprs={@Meta.Expr()}
)
final public class Hello  {





final public static Func.U<RealWorld, Short> $main(final Lazy<PreludeBase.TList<String/*<Character>*/>> arg$1) {
  return Prelude.putStrLn("Hello, World!");
}

  public static void main(final java.lang.String[] argv) {
    try {
      frege.run.RunTM.argv = argv;

        PreludeBase.TST.<Short>performUnsafe($main
               (Thunk.lazy(PreludeArrays.IListSource_JArray.<String/*<Character>*/>toList(argv)))
          ).call();
      frege.runtime.Runtime.stdout.get().close();
      frege.runtime.Runtime.stderr.get().close();

    } finally { frege.run.Concurrent.shutDownIfExists(); }
  }
}

然后我编译生成的java代码没有错误：

javac -cp frege3.jar build/Hello.class

然后我尝试运行代码：

cd build
java Hello

但这会返回一个错误：

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: frege/run8/Lazy
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
    at java.lang.Class.getMethod0(Class.java:3018)
    at java.lang.Class.getMethod(Class.java:1784)
    at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: frege.run8.Lazy
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 7 more

如何在 jvm 上运行生成的 frege java 代码？

我正在使用 java8

4

2 回答 2

4

您还需要frege3.jar在启动命令时添加类路径，所以试试这个：

java -cp .:frege3.jar Hello

假设frege3.jar和Hello.class都在当前目录中

于 2016-08-05T12:10:06.177 回答
0
  1. 您不需要额外的 javac 编译，这是由 frege 编译器自动完成的（除非被标志抑制）。
  2. 是的，这里有一个入门文档：https ://github.com/Frege/frege/wiki/Getting-Started
于 2016-08-06T01:04:38.197 回答