Semi constant strings in Scheme

Lecture notes - all slides and notes together

Slide 9 : 20

Semi constant strings in Scheme

When we compare an SGML family language with a Lisp family programming language we find some major syntactical differences. The observation about semi-constant strings is one of the most important

It would be convenient to support a semi constant string concept analogous to quasi quoted lists in Lisp

  <point> 
    A text with a 
    <a href="subsection/sec1.html">link</a> 
    to a <b>subsection</b>
  </point>

This is a typical HTML/XML fragment

  (point
    "A text with a 
     (a "link" 'href "subsection/sec.html")
     to a (b "subsection")
    ")

Here we attempt to use a semi-constant string in Scheme. This does actually not make sense.

  (point
    (string-append
      "A text with a " 
       (a "link" 'href "subsection/sec.html")
      " to a " (b "subsection")))

Here we see the solution we use in all our examples. This uses a plain Scheme programming approach.

We have dropped the idea of supporting semi-constant strings in Scheme

Instead we go for distinguished editor support of the 'string-append' forms