Ein einfacher Makroprozessor in Python 

main.py

techyle = \
{ 'uae': { 'type': 'markup', 'meaning': 'emphasized' }}

techyle_html = \
{ 'uae': { 'pre': '<em>', 'post': '</em>' }}

source = """\
This is `uae:text with `uae:markup``. Is this `uae:cool` or what?
"""

position = 0;

def at( n ):
    if n >= len( source ): return chr( 0 )
    else: return source[ n ]

def getnextch():
    global position
    if position >= len( source ): return chr( 0 )
    else: position += 1; return source[ position -  1 ]

def emit( text ):
  print( end=text )

def check_open():
  """is this an opening of markup?"""
  global position
  # print( '[', at( position ), at( position + 3 ), ']' )
  if( at( position )== 'u' and at( position + 3 )== ':' ):
    result = source[ position:position+3 ]
    position += 4
    return result
  else: return None

def check_text():
  """is this a text reference?"""
  # not yet implemented!
  return None

def pretext( code ):
  return techyle_html[ code ][ 'pre' ];

def posttext( code ):
  return techyle_html[ code ][ 'post' ];

stack = []

def push( text ):
  stack.append( text )

def pop():
  return stack.pop()

looping = True
while looping:
  ch = getnextch()
  if ch == chr( 0 ): break
  if ch != '`': emit( ch )
  else:
    type = check_open()
    if type: 
      text = check_text()
      if text:
        print( "TEXT REFERENCE NOT IMPLEMENTED." )
      else:
        emit( pretext( type ))
        push( posttext( type ))
    else:
      emit( pop() )

Protokoll

  File "main.py", line 2
    
    ^
SyntaxError: invalid syntax

Notizen

This is text with `uae:markup`.
  The tag »uae« means "emphasized". It is applied to the word
  "markup" using the pattern: `tag:...`. All tags have three
  letters and start with »u«.
  Now, I will answer a few questions:
  Q: How do you include a literal backquote in the text?
  A: Probably there will be an extension later with
  something like `utx:gravis` for this. This will create
  one »`« in the output. So if you like to manually markup text
  with a lot of backquotes, this language is not for you.
  Q: Are the patterns intended to be nestable?
  A: Yes, but this was not tested yet.
  Q: How do you diagnose errors?
  A: The first version does not emit diagnostics or
  recovery for errors in the source code. If there are
  mark-up errors in the source, it has undefined behavior.
  Q: What do you mean by "implementation" of a markup
  language?
  A: A translator that translates the language to at
  least one other markup language. The first implementation
  translates to HTML. So, for the input:
This is text with `uae:markup`. Is this cool or what?
  it outputs:
This is text with <em>markup</em>. Is this cool or what?
  And here is the source code (written in 35 minutes):