github.com/apache/arrow/go/v14@v14.0.1/arrow/compute/vector_hash.go (about)

     1  // Licensed to the Apache Software Foundation (ASF) under one
     2  // or more contributor license agreements.  See the NOTICE file
     3  // distributed with this work for additional information
     4  // regarding copyright ownership.  The ASF licenses this file
     5  // to you under the Apache License, Version 2.0 (the
     6  // "License"); you may not use this file except in compliance
     7  // with the License.  You may obtain a copy of the License at
     8  //
     9  // http://www.apache.org/licenses/LICENSE-2.0
    10  //
    11  // Unless required by applicable law or agreed to in writing, software
    12  // distributed under the License is distributed on an "AS IS" BASIS,
    13  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14  // See the License for the specific language governing permissions and
    15  // limitations under the License.
    16  
    17  //go:build go1.18
    18  
    19  package compute
    20  
    21  import (
    22  	"context"
    23  
    24  	"github.com/apache/arrow/go/v14/arrow"
    25  	"github.com/apache/arrow/go/v14/arrow/compute/internal/kernels"
    26  )
    27  
    28  var (
    29  	uniqueDoc = FunctionDoc{
    30  		Summary:     "Compute unique elements",
    31  		Description: "Return an array with distinct values. Nulls in the input are ignored",
    32  		ArgNames:    []string{"array"},
    33  	}
    34  )
    35  
    36  func Unique(ctx context.Context, values Datum) (Datum, error) {
    37  	return CallFunction(ctx, "unique", nil, values)
    38  }
    39  
    40  func UniqueArray(ctx context.Context, values arrow.Array) (arrow.Array, error) {
    41  	out, err := Unique(ctx, &ArrayDatum{Value: values.Data()})
    42  	if err != nil {
    43  		return nil, err
    44  	}
    45  	defer out.Release()
    46  
    47  	return out.(*ArrayDatum).MakeArray(), nil
    48  }
    49  
    50  func RegisterVectorHash(reg FunctionRegistry) {
    51  	unique, _, _ := kernels.GetVectorHashKernels()
    52  	uniqFn := NewVectorFunction("unique", Unary(), uniqueDoc)
    53  	for _, vd := range unique {
    54  		if err := uniqFn.AddKernel(vd); err != nil {
    55  			panic(err)
    56  		}
    57  	}
    58  	reg.AddFunction(uniqFn, false)
    59  }