unescape_string Subroutine

public subroutine unescape_string(str_in, str_out, error_message)

Remove the escape characters from a JSON string and return it.

The escaped characters are denoted by the \ character:

  • \" - quotation mark
  • \\ - reverse solidus
  • \/ - solidus
  • \b - backspace
  • \f - formfeed
  • \n - newline (LF)
  • \r - carriage return (CR)
  • \t - horizontal tab
  • \uXXXX - 4 hexadecimal digits

Arguments

Type IntentOptional AttributesName
character(kind=CK,len=*), intent(in) :: str_in

string as stored in a json_value

character(kind=CK,len=:), intent(out), allocatable:: str_out

decoded string

character(kind=CK,len=:), intent(out), allocatable:: error_message

will be allocated if there was an error

Calls

proc~~unescape_string~~CallsGraph proc~unescape_string unescape_string interface~to_unicode to_unicode proc~unescape_string->interface~to_unicode proc~to_uni to_uni interface~to_unicode->proc~to_uni proc~to_uni_vec to_uni_vec interface~to_unicode->proc~to_uni_vec
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Called By

proc~~unescape_string~~CalledByGraph proc~unescape_string unescape_string proc~parse_string parse_string proc~parse_string->proc~unescape_string
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Source Code


Source Code

    subroutine unescape_string(str_in, str_out, error_message)

    implicit none

    character(kind=CK,len=*),intent(in)              :: str_in  !! string as stored in a [[json_value]]
    character(kind=CK,len=:),allocatable,intent(out) :: str_out !! decoded string
    character(kind=CK,len=:),allocatable,intent(out) :: error_message !! will be allocated if there was an error

    integer :: i   !! counter
    integer :: n   !! length of str_in
    integer :: m   !! length of str_out
    character(kind=CK,len=1) :: c  !! for scanning each character in string

#if defined __GFORTRAN__
    character(kind=CK,len=:),allocatable :: tmp  !! for GFortran bug workaround
#endif

    if (scan(str_in,backslash)>0) then

        !there is at least one escape character, so process this string:

        n = len(str_in)
        str_out = repeat(space,n) !size the output string (will be trimmed later)
        m = 0  !counter in str_out
        i = 0  !counter in str_in

        do

            i = i + 1
            if (i>n) exit ! finished
            c = str_in(i:i) ! get next character in the string

            if (c == backslash) then

                if (i<n) then

                    i = i + 1
                    c = str_in(i:i) !character after the escape

                    if (any(c == [quotation_mark,backslash,slash, &
                         to_unicode(['b','f','n','r','t'])])) then

                        select case(c)
                        case (quotation_mark,backslash,slash)
                            !use d as is
                        case (CK_'b')
                             c = bspace
                        case (CK_'f')
                             c = formfeed
                        case (CK_'n')
                             c = newline
                        case (CK_'r')
                             c = carriage_return
                        case (CK_'t')
                             c = horizontal_tab
                        end select

                        m = m + 1
                        str_out(m:m) = c

                    else if (c == 'u') then !expecting 4 hexadecimal digits after
                                            !the escape character    [\uXXXX]

                        !for now, we are just returning them as is
                        ![not checking to see if it is a valid hex value]
                        !
                        ! Example:
                        !   123456
                        !   \uXXXX

                        if (i+4<=n) then
                            m = m + 1
                            str_out(m:m+5) = str_in(i-1:i+4)
                            i = i + 4
                            m = m + 5
                        else
                            error_message = 'Error in unescape_string:'//&
                                                 ' Invalid hexadecimal sequence'//&
                                                 ' in string: '//str_in(i-1:)
                            if (allocated(str_out)) deallocate(str_out)
                            return
                        end if

                    else
                        !unknown escape character
                        error_message = 'Error in unescape_string:'//&
                                             ' unknown escape sequence in string "'//&
                                             trim(str_in)//'" ['//backslash//c//']'
                        if (allocated(str_out)) deallocate(str_out)
                        return
                    end if

                else
                    !an escape character is the last character in
                    ! the string [this may not be valid syntax,
                    ! but just keep it]
                    m = m + 1
                    str_out(m:m) = c
                end if

            else
                m = m + 1
                str_out(m:m) = c
            end if

        end do

        !trim trailing space:
#if defined __GFORTRAN__
        ! workaround for Gfortran 6.1.0 bug
        tmp = str_out(1:m)
        str_out = tmp
#else
        str_out = str_out(1:m)
#endif

    else
        !there are no escape characters, so return as is:
        str_out = str_in
    end if

    end subroutine unescape_string


annotate_invalid_json compact_real_string decode_rfc6901 default_comp_ucs4 default_join_ucs4 default_neq_ucs4 destroy_json_core destroy_json_data encode_rfc6901 escape_string get_current_line_from_file_sequential get_current_line_from_file_stream get_json_core_in_file initialize_json_core initialize_json_core_in_file initialize_json_file initialize_json_file_v2 integer_to_string json_add_double_by_path json_add_double_vec_by_path json_add_integer_by_path json_add_integer_vec_by_path json_add_logical_by_path json_add_logical_vec_by_path json_add_member_by_path json_add_string_by_path json_add_string_by_path_path_ascii json_add_string_by_path_value_ascii json_add_string_vec_by_path json_add_string_vec_by_path_path_ascii json_add_string_vec_by_path_value_ascii json_check_for_errors json_clear_exceptions json_clone json_core json_count json_create_by_path json_failed json_file json_file_add_double json_file_add_double_vec json_file_add_integer json_file_add_integer_vec json_file_add_logical json_file_add_logical_vec json_file_add_object json_file_add_string json_file_add_string_path_ascii json_file_add_string_value_ascii json_file_add_string_vec json_file_add_string_vec_path_ascii json_file_add_string_vec_vec_ascii json_file_check_for_errors json_file_clear_exceptions json_file_destroy json_file_failed json_file_get_alloc_string_vec json_file_get_double json_file_get_double_vec json_file_get_integer json_file_get_integer_vec json_file_get_logical json_file_get_logical_vec json_file_get_object json_file_get_root json_file_get_string json_file_get_string_vec json_file_load json_file_load_from_string json_file_move_pointer json_file_print_1 json_file_print_2 json_file_print_error_message json_file_print_to_console json_file_print_to_string json_file_traverse json_file_update_integer json_file_update_logical json_file_update_real json_file_update_string json_file_update_string_name_ascii json_file_update_string_val_ascii json_file_variable_info json_file_variable_matrix_info json_get_alloc_string_vec json_get_alloc_string_vec_by_path json_get_array json_get_array_by_path json_get_by_path json_get_by_path_default json_get_by_path_rfc6901 json_get_double json_get_double_by_path json_get_double_vec json_get_double_vec_by_path json_get_integer json_get_integer_by_path json_get_integer_vec json_get_integer_vec_by_path json_get_logical json_get_logical_by_path json_get_logical_vec json_get_logical_vec_by_path json_get_next json_get_parent json_get_path json_get_previous json_get_string json_get_string_by_path json_get_string_vec json_get_string_vec_by_path json_get_tail json_info json_info_by_path json_initialize json_matrix_info json_matrix_info_by_path json_parse_file json_parse_string json_print_1 json_print_2 json_print_error_message json_string_info json_throw_exception json_traverse json_update_double json_update_integer json_update_logical json_update_string json_update_string_name_ascii json_update_string_val_ascii json_value_add_double json_value_add_double_vec json_value_add_integer json_value_add_integer_vec json_value_add_logical json_value_add_logical_vec json_value_add_member json_value_add_null json_value_add_string json_value_add_string_name_ascii json_value_add_string_val_ascii json_value_add_string_vec json_value_add_string_vec_name_ascii json_value_add_string_vec_val_ascii json_value_clone_func json_value_create json_value_create_array json_value_create_double json_value_create_integer json_value_create_logical json_value_create_null json_value_create_object json_value_create_string json_value_destroy json_value_get_child json_value_get_child_by_index json_value_get_child_by_name json_value_insert_after json_value_insert_after_child_by_index json_value_is_child_of json_value_print json_value_remove json_value_remove_if_present json_value_rename json_value_replace json_value_reverse json_value_swap json_value_to_string json_value_validate lowercase_character lowercase_string name_equal parse_array parse_for_chars parse_number parse_object parse_string parse_value pop_char push_char real_to_string replace_string set_json_core_in_file string_to_dble string_to_int string_to_integer string_to_real to_array to_double to_integer to_logical to_null to_object to_string to_uni to_uni_vec to_unicode ucs4_comp_default ucs4_join_default ucs4_neq_default unescape_string valid_json_hex wrap_json_add_double_by_path wrap_json_add_double_vec_by_path wrap_json_add_integer_by_path wrap_json_add_integer_vec_by_path wrap_json_add_logical_by_path wrap_json_add_logical_vec_by_path wrap_json_add_member_by_path wrap_json_add_string_by_path wrap_json_add_string_vec_by_path wrap_json_create_by_path wrap_json_file_add_double wrap_json_file_add_double_vec wrap_json_file_add_integer wrap_json_file_add_integer_vec wrap_json_file_add_logical wrap_json_file_add_logical_vec wrap_json_file_add_object wrap_json_file_add_string wrap_json_file_add_string_vec wrap_json_file_get_alloc_string_vec wrap_json_file_get_double wrap_json_file_get_double_vec wrap_json_file_get_integer wrap_json_file_get_integer_vec wrap_json_file_get_logical wrap_json_file_get_logical_vec wrap_json_file_get_object wrap_json_file_get_string wrap_json_file_get_string_vec wrap_json_file_load_from_string wrap_json_file_update_integer wrap_json_file_update_logical wrap_json_file_update_real wrap_json_file_update_string wrap_json_file_variable_info wrap_json_file_variable_matrix_info wrap_json_get_alloc_string_vec_by_path wrap_json_get_array_by_path wrap_json_get_by_path wrap_json_get_double_by_path wrap_json_get_double_vec_by_path wrap_json_get_integer_by_path wrap_json_get_integer_vec_by_path wrap_json_get_logical_by_path wrap_json_get_logical_vec_by_path wrap_json_get_path wrap_json_get_string_by_path wrap_json_get_string_vec_by_path wrap_json_info_by_path wrap_json_matrix_info_by_path wrap_json_parse_string wrap_json_throw_exception wrap_json_update_double wrap_json_update_integer wrap_json_update_logical wrap_json_update_string wrap_json_value_add_double wrap_json_value_add_double_vec wrap_json_value_add_integer wrap_json_value_add_integer_vec wrap_json_value_add_logical wrap_json_value_add_logical_vec wrap_json_value_add_null wrap_json_value_add_string wrap_json_value_add_string_vec wrap_json_value_create_array wrap_json_value_create_double wrap_json_value_create_integer wrap_json_value_create_logical wrap_json_value_create_null wrap_json_value_create_object wrap_json_value_create_string wrap_json_value_get_child_by_name wrap_json_value_remove_if_present wrap_json_value_rename