goenv

var (
	// ErrNoStruct error when given parametetr is not struct
	ErrNoStruct = errors.New("given parameter is not a struct")
	// ErrNoPtr error when given parameter is not pointer
	ErrNoPtr = errors.New("given parameter is not a pointer")
	// DefaultTag tag for loading env key names from struct
	DefaultTag = "env"

	// Default value of env variable
	DefaultValueTag = "default"
	// Required env variable
	DefaultRequiredTag = "required"

	// Built-in parser functions
	BuiltInParsers = map[reflect.Kind]ParserFunc{
		reflect.Bool: func(value string) (interface{}, error) {
			return strconv.ParseBool(value)
		},
		reflect.Int: func(value string) (interface{}, error) {
			return strconv.Atoi(value)
		},
		reflect.Int8: func(value string) (interface{}, error) {
			val, err := strconv.ParseInt(value, 10, 8)
			if err != nil {
				return nil, err
			}

			return int8(val), nil
		},
		reflect.Int16: func(value string) (interface{}, error) {
			val, err := strconv.ParseInt(value, 10, 16)
			if err != nil {
				return nil, err
			}

			return int16(val), nil
		},
		reflect.Int32: func(value string) (interface{}, error) {
			val, err := strconv.ParseInt(value, 10, 32)
			if err != nil {
				return nil, err
			}

			return int32(val), nil
		},
		reflect.Int64: func(value string) (interface{}, error) {
			return strconv.ParseInt(value, 10, 64)
		},
		reflect.Uint: func(value string) (interface{}, error) {
			val, err := strconv.ParseUint(value, 10, 0)
			if err != nil {
				return nil, err
			}

			return uint(val), nil
		},
		reflect.Uint8: func(value string) (interface{}, error) {
			val, err := strconv.ParseUint(value, 10, 8)
			if err != nil {
				return nil, err
			}

			return uint8(val), nil
		},
		reflect.Uint16: func(value string) (interface{}, error) {
			val, err := strconv.ParseUint(value, 10, 16)
			if err != nil {
				return nil, err
			}

			return uint16(val), nil
		},
		reflect.Uint32: func(value string) (interface{}, error) {
			val, err := strconv.ParseUint(value, 10, 32)
			if err != nil {
				return nil, err
			}

			return uint32(val), nil
		},
		reflect.Uint64: func(value string) (interface{}, error) {
			return strconv.ParseUint(value, 10, 64)
		},
		reflect.Float32: func(value string) (interface{}, error) {
			val, err := strconv.ParseFloat(value, 32)
			if err != nil {
				return nil, err
			}

			return float32(val), nil
		},
		reflect.Float64: func(value string) (interface{}, error) {
			return strconv.ParseFloat(value, 64)
		},
		reflect.String: func(value string) (interface{}, error) {
			return value, nil
		},
	}
)