我目前正在撰写Parser JavaTokenParsers，Scala Grammar list = "[" [ { expr "," } expr ] "]"
class ExpParser extends JavaTokenParsers {
def expr: Parser[Expression] = int | list | bool | id
[...]
private def list: Parser[Liste] = "[" ~> repsep(expr, ",") ~ expr <~ "]" ^^ {
case el ~ e => Liste(List(el, e))
} // error
[..]
}
object ParseProgram extends ExpParser {
def parse(s: String): ParseResult[Expression] = {
parseAll(expr, s)
}
}
sealed trait Expression
[...]
case class Liste(l: List[Expression]) extends Expression
[...]
我的解析器类：
List我的案例类：
Liste Constructor我尝试创建一个新的list并将其传递给Expressions，但我收到以下错误消息：
类型不匹配，预期：列表[表达式]，实际：列表[对象]
那么我怎样才能将repsep(expr, ",")的{{1}} expression传递给~ expr以及list Liste Constructor bool removeMultiples( int multiple )
{
bool success;
auto it = std::remove_if(v.begin(), v.end(), [multiple](int i){return i%multiple == 0;});
if ( ( success = it != v.end() ) ) v.erase( it, v.end() );
return success;
}
react-native run-android * What went wrong:
Execution failed for task ':app:preDexDebug'.
> com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command '/Library/Java/JavaVirtualMachines/jdk1.7.0_67.jdk/Contents/Home/bin/java'' finished with non-zero exit value 1
到package com.wosyldelivery;
import android.app.Application;
import android.util.Log;
import com.facebook.react.ReactApplication;
import com.microsoft.codepush.react.CodePush;
import com.oblador.vectoricons.VectorIconsPackage;
import com.facebook.react.ReactInstanceManager;
import com.facebook.react.ReactNativeHost;
import com.facebook.react.ReactPackage;
import com.facebook.react.shell.MainReactPackage;
import java.util.Arrays;
import java.util.List;
public class MainApplication extends Application implements ReactApplication {
private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) {
@Override
public boolean getUseDeveloperSupport() {
return BuildConfig.DEBUG;
}
@Override
protected List<ReactPackage> getPackages() {
return Arrays.<ReactPackage>asList(
new MainReactPackage(),
new VectorIconsPackage()
);
}
@Override
protected String getJSBundleFile() {
return CodePush.getJSBundleFile();
}
};
@Override
public ReactNativeHost getReactNativeHost() {
return mReactNativeHost;
}
}
？
答案 0 :(得分：2)
repsep(expr, ",")为您提供Parser[List[Expression]]并且还不够吗？
private def list: Parser[Liste] = "[" ~> repsep(expr, ",") <~ "]" ^^ {
case el => Liste(el)
}
你的原始解析意味着有一个像[True,FalseTrue]这样的列表，这就是你想要的吗？