Markup - why and how

Heinz Wittenbrink

2017-10-24

Goals of the session

Understanding how digital (text) content is stored and processed

Knowledge of basic characteristics of markup languages

Descriptive Markup
Difference of text and markup

Basic knowledge about text encoding

How is text translated into bytes?
ASCII and Unicode

Knowledge of basics of markup processing

What is parsing?
Document Object Model

Descriptive Markup

Essentials

Digital content is mostly stored as marked up text.
The grammar of the markup is standardized.
The standardized markup is the base of the processing of the text by software.
How software processes the text depends largely on the quality of the markup.

Markup before the digital age

The idea and terminology evolved from the “marking up” of paper manuscripts, i.e., the revision instructions by editors, traditionally written with a blue pencil on authors’ manuscripts.

Markup language - Wikipedia

Source: Markup is


<!DOCTYPE html>

<html>

    <head>

        <title>Sample Manuscripts</title>

        <style type="text/css">

        h1 {font-family: Helvetica, sans-serif; font-size: 16}

        p {font-family: Times-Roman, serif; font-size: 16}

        </style>

    </head>

    <body>

        <h1>Sample Manuscripts throughout the Ages</h1>

        <p>The funny thing about sample manuscripts is that they never say anything really interesting.</p>

    </body>

</html>

Procedural vs. descriptive markup

Control of defined applications by procedural markup: Defines the state of processing applications
Descriptive markup: Describes text and leaves the processing to the application

Example PCL


Ec(s0Saufrechter Text Ec(s1Skursiv gesetzter Text

How does a computer distinguish text and markup?

Markup delimiters in HTML and XML: <, >,
Markup delimiters for Entities: &, ;(referencing special characters, escaping the literal values of < and >
Possible markup delimiters in SGML: [, ], {, }

Encoding: Transforming text into bytes

Source: Ascii Table - ASCII character codes and html, octal, hex and decimal chart conversion

Source: Ascii Table - ASCII character codes and html, octal, hex and decimal chart conversion

Source: How does unicode SMS Works? - Quora

Parsing: How a computer reads text

Parsing (US: /ˈpɑːrsɪŋ/; UK: /ˈpɑːzɪŋ/), syntax analysis or syntactic analysis is the process of analysing a string of symbols, either in natural language or in computer languages, conforming to the rules of a formal grammar. The term parsing comes from Latin pars (orationis), meaning part (of speech).

Parsing - Wikipedia