github.com/MontFerret/ferret@v0.18.0/pkg/stdlib/arrays/minus.go (about)

     1  package arrays
     2  
     3  import (
     4  	"context"
     5  
     6  	"github.com/MontFerret/ferret/pkg/runtime/core"
     7  	"github.com/MontFerret/ferret/pkg/runtime/values"
     8  	"github.com/MontFerret/ferret/pkg/runtime/values/types"
     9  )
    10  
    11  // MINUS return the difference of all arrays specified.
    12  // The order of the result array is undefined and should not be relied on. Duplicates will be removed.
    13  // @param {Any[], repeated} arrays - An arbitrary number of arrays as multiple arguments (at least 2).
    14  // @return {Any[]} - An array of values that occur in the first array, but not in any of the subsequent arrays.
    15  func Minus(_ context.Context, args ...core.Value) (core.Value, error) {
    16  	err := core.ValidateArgs(args, 2, core.MaxArgs)
    17  
    18  	if err != nil {
    19  		return values.None, err
    20  	}
    21  
    22  	intersections := make(map[uint64]core.Value)
    23  	capacity := values.NewInt(0)
    24  
    25  	for idx, i := range args {
    26  		idx := idx
    27  		err := core.ValidateType(i, types.Array)
    28  
    29  		if err != nil {
    30  			return values.None, err
    31  		}
    32  
    33  		arr := i.(*values.Array)
    34  
    35  		arr.ForEach(func(value core.Value, _ int) bool {
    36  			h := value.Hash()
    37  
    38  			// first array, fill out the map
    39  			if idx == 0 {
    40  				capacity = arr.Length()
    41  				intersections[h] = value
    42  
    43  				return true
    44  			}
    45  
    46  			_, exists := intersections[h]
    47  
    48  			// if it exists in the first array, remove it
    49  			if exists {
    50  				delete(intersections, h)
    51  			}
    52  
    53  			return true
    54  		})
    55  	}
    56  
    57  	result := values.NewArray(int(capacity))
    58  
    59  	for _, item := range intersections {
    60  		result.Push(item)
    61  	}
    62  
    63  	return result, nil
    64  }