emph.laml - Elements that depend on their immediate context.

Slide 22 : 26 Program 4

(load (string-append laml-dir "laml.scm"))
(laml-style "simple-xhtml1.0-transitional-validating")
(lib-load "xhtml1.0-convenience.scm")
(set-xml-accept-extended-contents-in 'xhtml10-transitional #t)

(define meta-props 
 (list 'http-equiv "Content-Type" 'content "text/html; charset=iso-8859-1"))

; Return a meta text keywords from the emphasized words in the entire document.
(define (count-elements el-name)
  (lambda (root-ast parent-ast)
    (length (match-ast root-ast (location-step 'descendant "p")))))

(define word
 (xml-in-laml-abstraction
   (lambda (c a)
     (lambda (root-ast parent-ast)
       (cond ((equal? (ast-element-name parent-ast) "b") 
                 (span 'css:font-size "150%" c a))
             ((equal? (ast-element-name parent-ast) "em") 
                 (font 'color (rgb-color-encoding red) c a))
             (else (list c a)))))))

(write-html '(pp prolog)
 (html 
  (head 
   (meta meta-props) 
   (title "Demo of simple document reflection"))
  (body 
    (h1 "Illustration of element elements that depend on their immediate contexts." )

    (p "This document shows who to define context sensite elements")

    (p "This is a demo of simple document introspection aided by" 
       (word "delayed procedural content items")_ "." )

    (p "A delayed procedural content item is a" (b (word "closure")) 
       "which is evaluated at" (em (word "documentation expansion time")) _ "." )

    (p "We show how to extract" (word "meta" "keywords") 
       "from designated and marked up keywords in the text. Notice that the keyword
        element mirror function is produced by an XML-in-LAML abstraction." )

    (when-generated))))

(end-laml)