github.com/MontFerret/ferret@v0.18.0/pkg/stdlib/arrays/nth.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  // NTH returns the element of an array at a given position.
    12  // It is the same as anyArray[position] for positive positions, but does not support negative positions.
    13  // If position is negative or beyond the upper bound of the array, then NONE will be returned.
    14  // @param {Any[]} array - An array with elements of arbitrary type.
    15  // @param {Int} index - Position of desired element in array, positions start at 0.
    16  // @return {Any} - The array element at the given position.
    17  func Nth(_ context.Context, args ...core.Value) (core.Value, error) {
    18  	err := core.ValidateArgs(args, 2, 2)
    19  
    20  	if err != nil {
    21  		return values.None, err
    22  	}
    23  
    24  	err = core.ValidateType(args[0], types.Array)
    25  
    26  	if err != nil {
    27  		return values.None, err
    28  	}
    29  
    30  	err = core.ValidateType(args[1], types.Int)
    31  
    32  	if err != nil {
    33  		return values.None, err
    34  	}
    35  
    36  	arr := args[0].(*values.Array)
    37  	idx := args[1].(values.Int)
    38  
    39  	return arr.Get(idx), nil
    40  }