rnrs_mutable_pairs.go

//
// Copyright (c) 2022-2023 Markku Rossi
//
// All rights reserved.
//
// The (rnrs mutable-pairs (6)) library.
//

package scheme

import (
	"fmt"

	"github.com/markkurossi/scheme/types"
)

var rnrsMutablePairsBuiltins = []Builtin{
	{
		Name:   "set-car!",
		Args:   []string{"pair", "obj"},
		Return: types.Any,
		Native: func(scm *Scheme, args []Value) (Value, error) {
			pair, ok := args[0].(Pair)
			if !ok {
				return nil, fmt.Errorf("not a pair: %v", args[0])
			}
			err := pair.SetCar(args[1])
			if err != nil {
				return nil, err
			}
			return nil, nil
		},
	},
	{
		Name:   "set-cdr!",
		Args:   []string{"pair", "obj"},
		Return: types.Any,
		Native: func(scm *Scheme, args []Value) (Value, error) {
			pair, ok := args[0].(Pair)
			if !ok {
				return nil, fmt.Errorf("not a pair: %v", args[0])
			}
			err := pair.SetCdr(args[1])
			if err != nil {
				return nil, err
			}
			return nil, nil
		},
	},
}