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Manual Reference Pages  - add_backslash (3m_unicode)

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NAME

ADD_BACKSLASH(3f) - [M_unicode:CONVERSION] Convert UTF-8 encoded data to ASCII-7 C-style backslash escape sequences (LICENSE:MIT)

CONTENTS

Synopsis
Description
Options
Returns
Examples
Author
License

SYNOPSIS

function add_backslash(line) result(out)

    type(unicode_type),intent(in) :: line
     or
    character(len=*),intent(in)   :: line

    character(len=:),allocatable  :: out

DESCRIPTION

ADD_BACKSLASH(3) replaces non-printable ASCII-7 characters and UTF-8 non-ASCII-7 characters to ASCII-7 escape sequences.

Escape sequences will all be preceded by a backslash.

The conversion rules are intended to comply with the conversions performed by the gfortran -fbackslash extension and C-style escape sequences.

Escape sequences

    \      backslash
    0      null
    a      alert (BEL) -- g is an alias for a
    b      backspace
    e      escape
    f      form feed
    n      new line
    r      carriage return
    t      horizontal tab
    v      vertical tab

    xHH        one-byte characters with hexadecimal value HH (2 digits)
    uZZZZ      Unicode codepoint value from FF+1 to FFFF.
    UZZZZZZZZ  Unicode codepoint value from FFFF+1 to FFFFFFFF.

OPTIONS

LINE	An ASCII bytestream optionally containing UTF-8 encoded data or a UNICODE_TYPE() string to convert to an ASCII string containing C-style backslash escape sequences.

RETURNS

The return value is the input line with all characters not representing printable ASCII characters converted to their C-style backslash escape sequences.

EXAMPLES

Sample Program:

     program demo_add_backslash
     ! filter to replace all but printable ASCII-7 characters
     ! with C-like escape sequences
     use iso_fortran_env, only : stdout => output_unit
     use M_unicode,       only : add_backslash
     use M_unicode,       only : assignment(=)
     use M_unicode,       only : ut => unicode_type
     implicit none
     character(len=:),allocatable :: poem(:)
     type(ut)                     :: uline
     character(len=:),allocatable :: aline
     integer                      :: i
        !
        ! “The Crow and the Fox” by Jean de la Fontaine
        !
        poem=[character(len=255) :: &
        ’Le Corbeau et le Renard                               ’,&
        ’                                                      ’,&
        ’Maître Corbeau, sur un arbre perché,                  ’,&
        ’Tenait en son bec un fromage.                         ’,&
        ’Maître Renard, par l’odeur alléché,                   ’,&
        ’Lui tint à peu près ce langage :                      ’,&
        ’«Hé ! bonjour, Monsieur du Corbeau.                   ’,&
        ’Que vous êtes joli ! que vous me semblez beau !       ’,&
        ’Sans mentir, si votre ramage                          ’,&
        ’Se rapporte à votre plumage,                          ’,&
        ’Vous êtes le Phénix des hôtes de ces bois.»           ’,&
        ’A ces mots le Corbeau ne se sent pas de joie ;        ’,&
        ’Et pour montrer sa belle voix,                        ’,&
        ’Il ouvre un large bec, laisse tomber sa proie.        ’,&
        ’Le Renard s’en saisit, et dit : «Mon bon Monsieur,    ’,&
        ’Apprenez que tout flatteur                            ’,&
        ’Vit aux dépens de celui qui l’écoute :                ’,&
        ’Cette leçon vaut bien un fromage, sans doute.»        ’,&
        ’Le Corbeau, honteux et confus,                        ’,&
        ’Jura, mais un peu tard, qu’on ne l’y prendrait plus.  ’,&
        ’ -- Jean de la Fontaine                               ’]

        do i=1,size(poem)
           ! convert UTF-8 to UNICODE_TYPE for demonstration purposes
           uline=poem(i)
           aline=add_backslash(uline)
           write(stdout,’(g0)’)trim(aline)
        enddo

        do i=1,size(poem)
           aline=add_backslash(poem(i))
           write(stdout,’(g0)’)trim(aline)
        enddo

     end program demo_add_backslash

AUTHOR

John S. Urban

LICENSE

    MIT

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