Question

我正在尝试在打字稿中使用类组合。

const FoodMixin = superclass => class extends superclass {
  eat(food) {
    console.log(`Eating ${food}`);
  }
};

class Animal<T> {
  prop: T;
  constructor(public name) {
  }
}

interface Prop {}

class Dog extends FoodMixin(Animal<Prop>) {
  constructor(...args) {
    super(...args)
  }
}

我的问题是我无法将通用传递给Animal类。以下行引发了一个打字稿错误：

class Dog extends FoodMixin(Animal<Prop>)

预计有1个参数，但得到2个

我如何通过通用？

Answer 1

当使用函数或构造函数作为值时，您无法指定类型参数。

您可以显式指定type参数（尽管这会导致静态方法丢失：

892520 [main] INFO  org.apache.pig.tools.pigstats.ScriptState  - Pig features used in the script: GROUP_BY,FILTER
18/03/28 00:56:09 INFO pigstats.ScriptState: Pig features used in the script: GROUP_BY,FILTER
1892554 [main] INFO  org.apache.pig.data.SchemaTupleBackend  - Key [pig.schematuple] was not set... will not generate code.
18/03/28 00:56:09 INFO data.SchemaTupleBackend: Key [pig.schematuple] was not set... will not generate code.
1892555 [main] INFO  org.apache.pig.newplan.logical.optimizer.LogicalPlanOptimizer  - {RULES_ENABLED=[ConstantCalculator, LoadTypeCastInserter, PredicatePushdownOptimizer, StreamTypeCastInserter], RULES_DISABLED=[AddForEach, ColumnMapKeyPrune, GroupByConstParallelSetter, LimitOptimizer, MergeFilter, MergeForEach, NestedLimitOptimizer, PartitionFilterOptimizer, PushDownForEachFlatten, PushUpFilter, SplitFilter]}
18/03/28 00:56:09 INFO optimizer.LogicalPlanOptimizer: {RULES_ENABLED=[ConstantCalculator, LoadTypeCastInserter, PredicatePushdownOptimizer, StreamTypeCastInserter], RULES_DISABLED=[AddForEach, ColumnMapKeyPrune, GroupByConstParallelSetter, LimitOptimizer, MergeFilter, MergeForEach, NestedLimitOptimizer, PartitionFilterOptimizer, PushDownForEachFlatten, PushUpFilter, SplitFilter]}
1892591 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezLauncher  - Tez staging directory is /tmp/temp383666093 and resources directory is /tmp/temp383666093
18/03/28 00:56:09 INFO tez.TezLauncher: Tez staging directory is /tmp/temp383666093 and resources directory is /tmp/temp383666093
1892592 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.plan.TezCompiler  - File concatenation threshold: 100 optimistic? false
18/03/28 00:56:09 INFO plan.TezCompiler: File concatenation threshold: 100 optimistic? false
1892593 [main] INFO  org.apache.pig.backend.hadoop.executionengine.util.AccumulatorOptimizerUtil  - Reducer is to run in accumulative mode.
18/03/28 00:56:09 INFO util.AccumulatorOptimizerUtil: Reducer is to run in accumulative mode.
1892606 [main] INFO  org.apache.pig.builtin.PigStorage  - Using PigTextInputFormat
18/03/28 00:56:09 INFO builtin.PigStorage: Using PigTextInputFormat
18/03/28 00:56:09 INFO input.FileInputFormat: Total input files to process : 1
1892626 [main] INFO  org.apache.pig.backend.hadoop.executionengine.util.MapRedUtil  - Total input paths to process : 1
18/03/28 00:56:09 INFO util.MapRedUtil: Total input paths to process : 1
1892627 [main] INFO  org.apache.pig.backend.hadoop.executionengine.util.MapRedUtil  - Total input paths (combined) to process : 1
18/03/28 00:56:09 INFO util.MapRedUtil: Total input paths (combined) to process : 1
18/03/28 00:56:09 INFO hadoop.MRInputHelpers: NumSplits: 1, SerializedSize: 408
1892653 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezJobCompiler  - Local resource: joda-time-2.9.4.jar
18/03/28 00:56:09 INFO tez.TezJobCompiler: Local resource: joda-time-2.9.4.jar
1892653 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezJobCompiler  - Local resource: pig-0.17.0-core-h2.jar
18/03/28 00:56:09 INFO tez.TezJobCompiler: Local resource: pig-0.17.0-core-h2.jar
1892653 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezJobCompiler  - Local resource: antlr-runtime-3.4.jar
18/03/28 00:56:09 INFO tez.TezJobCompiler: Local resource: antlr-runtime-3.4.jar
1892653 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezJobCompiler  - Local resource: automaton-1.11-8.jar
18/03/28 00:56:09 INFO tez.TezJobCompiler: Local resource: automaton-1.11-8.jar
1892709 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezDagBuilder  - For vertex - scope-239: parallelism=1, memory=1536, java opts=-Djava.net.preferIPv4Stack=true -Dhadoop.metrics.log.level=WARN -Xmx1229m -Dlog4j.configuratorClass=org.apache.tez.common.TezLog4jConfigurator -Dlog4j.configuration=tez-container-log4j.properties -Dyarn.app.container.log.dir=<LOG_DIR> -Dtez.root.logger=INFO,CLA 
18/03/28 00:56:09 INFO tez.TezDagBuilder: For vertex - scope-239: parallelism=1, memory=1536, java opts=-Djava.net.preferIPv4Stack=true -Dhadoop.metrics.log.level=WARN -Xmx1229m -Dlog4j.configuratorClass=org.apache.tez.common.TezLog4jConfigurator -Dlog4j.configuration=tez-container-log4j.properties -Dyarn.app.container.log.dir=<LOG_DIR> -Dtez.root.logger=INFO,CLA 
1892709 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezDagBuilder  - Processing aliases: filter_input,groupinp,inp
18/03/28 00:56:09 INFO tez.TezDagBuilder: Processing aliases: filter_input,groupinp,inp
1892709 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezDagBuilder  - Detailed locations: inp[1,6],inp[-1,-1],filter_input[2,15],groupinp[3,11]
18/03/28 00:56:09 INFO tez.TezDagBuilder: Detailed locations: inp[1,6],inp[-1,-1],filter_input[2,15],groupinp[3,11]
1892709 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezDagBuilder  - Pig features in the vertex: 
18/03/28 00:56:09 INFO tez.TezDagBuilder: Pig features in the vertex: 
1892744 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezDagBuilder  - Set auto parallelism for vertex scope-240
18/03/28 00:56:09 INFO tez.TezDagBuilder: Set auto parallelism for vertex scope-240
1892744 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezDagBuilder  - For vertex - scope-240: parallelism=1, memory=3072, java opts=-Djava.net.preferIPv4Stack=true -Dhadoop.metrics.log.level=WARN -Xmx2458m -Dlog4j.configuratorClass=org.apache.tez.common.TezLog4jConfigurator -Dlog4j.configuration=tez-container-log4j.properties -Dyarn.app.container.log.dir=<LOG_DIR> -Dtez.root.logger=INFO,CLA 
18/03/28 00:56:09 INFO tez.TezDagBuilder: For vertex - scope-240: parallelism=1, memory=3072, java opts=-Djava.net.preferIPv4Stack=true -Dhadoop.metrics.log.level=WARN -Xmx2458m -Dlog4j.configuratorClass=org.apache.tez.common.TezLog4jConfigurator -Dlog4j.configuration=tez-container-log4j.properties -Dyarn.app.container.log.dir=<LOG_DIR> -Dtez.root.logger=INFO,CLA 
1892744 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezDagBuilder  - Processing aliases: sum_occ
18/03/28 00:56:09 INFO tez.TezDagBuilder: Processing aliases: sum_occ
1892744 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezDagBuilder  - Detailed locations: sum_occ[5,10]
18/03/28 00:56:09 INFO tez.TezDagBuilder: Detailed locations: sum_occ[5,10]
1892745 [main] INFO  org.apache.pig.backend.hadoop.executionengine.tez.TezDagBuilder  - Pig features in the vertex: GROUP_BY
18/03/28 00:56:09 INFO tez.TezDagBuilder: Pig features in the vertex: GROUP_BY
1892762 [main] ERROR org.apache.pig.tools.grunt.Grunt  - ERROR 2017: Internal error creating job configuration.
18/03/28 00:56:09 ERROR grunt.Grunt: ERROR 2017: Internal error creating job configuration.
Details at logfile: /mnt/var/log/pig/pig_1522196676602.log

或者您可以创建一个继承const FoodMixin = function <T extends new (...arsg: any[]) => any>(superclass: T) { return class extends superclass { eat(food: string) { console.log(`Eating ${food}`); } }; } class Animal<T> { prop?: T ; constructor(public name: string) { } breathe() : void{} static mutate(): void{} } class Dog extends FoodMixin<new (name: string) => Animal<Prop>>(Animal) { constructor(name: string) { super("") } } var dog = new Dog(""); dog.breathe(); dog.eat(""); dog.prop // is Prop Dog.mutate // error的corect实例化的匿名类，然后一切都按预期工作。

Animal

打字稿类组成泛型

1 个答案: