4.7.8. Domain specific languages (Minilanguages)

• at a certain level of complexity a mini-language can help to
  further sustain the mechanism and policy seperation

• two ways: internal and external DSL

• internal: use an existing language (extend or embed)
  • examples: Lisp in emacs, Ruby

• external: create a new language (write a parser)
  • lex and yacc
  • better: ANTLR
  • examples: dtc, dc, awk, graphviz