Ani - An Interpreter for Action Notation.

Synopsis

ani [ filename ]

Description

Action semantics is a formalism for the specification of programming languages [1,2]. In action semantics the meaning of a program is an action. Ani is an interpreter for actions: given an action, Ani will perform it. The outcome of the performance can be visualized through a convenient output.

Some Features

• 'a1 or a2' is pseudo-nondeterministic.

• The sort operations 'meet' and 'join' can be used to construct new sorts. Also the 'subsort' relation is defined.

The result of the interpretation of an action has the fol- lowing format:

Outcome [outcome status]

Transients

Bindings

Storage

Commitment

For example, the interpretation of the action

bind "x" to 4 or bind "y" to true has the two possible outputs below:

Outcome Completed!
Transients empty-transients
Bindings { y --> true }
Storage empty-storage
Commitment Uncommitted action!

Outcome Completed!
Transients empty-transients
Bindings { x --> 4 }
Storage empty-storage
Commitment Uncommitted action!

If an action diverges, Ani diverges, and in this case, there is no output (the action 'diverge' is interpreted as 'unfolding unfold').

Usage

After load the interpreter, you will see the interpreter prompt 'Ani '. To see information about Ani type '\help'. The following examples illustrate how to use Ani:

• Example 1. To interpret the action 'give 4 then complete':

  Ani give 4 then complete

• Example 2. To interpret the action 'bind "x" to 4.0':

  Ani bind "x" to 4.0

• Example 3. To interpret the action 'fail or diverge', that is in a file called 'crazy.an':

  Ani \iaf crazy

• Example 4. To see how the action 'give 1' is represented inside Ani type:

  Ani \parse give 1

• \iaf filename Interprets the action in the file 'filename.an'.
• \parse action Parses the action action.
• \parsef filename Parses the action in the file 'filename.an'.
• The following useful UNIX commands are also available at top level:
  • \cd cd-arguments
    
  • \ls ls-argumenst
    
  • \more more-arguments
    
  • \system UNIX-command

• After the interpretation of an action, the following Ani directives can be used to inspect the contents of transients, bindings and storage, in the form they are represented internally:
  • \transients (or \t)
  • \bindings (or \b)
  • \storage (or \s)

• The following directives provide some on-line help facilities:
  • \help Displays Ani's manual page.
  • \actions Displays a list of the actions currently implemented.
  • \data Display a list of sorts and data operations currently implemented.

See ani/man/ActionNotation for the set of action notation currently implemented.

Data Notation

See ani/man/DataNotation for the set of data notation currently implemented.

Files

ani/ANNOUNCE announcement file
ani/CONDITIONS copyright note
ani/FILES distribution directory tree
ani/HISTORY history of this and previous versions
ani/INSTALLATION installation guide
ani/MANUAL this file (manual page)
ani/README general information on Ani
ani/actions/ many examples of actions
ani/doc/ supporting documentation
ani/interface/ user interface source files
ani/interpreter/ action notation interpreter source files
ani/parser/ action notation parser source files

Standard ML

Standard ML of New Jersey, Version 0.93, February 15, 1993.

Version

Version 0.22 23 August 1993.

Author

Hermano Moura (hermano@di.ufpe.br)
Federal University of Pernambuco
Department of Informatics

Deryck Brown (Robert Gordon University) provided the original action notation parser used by Ani.

See Also

ag (actioneer generator).

References

1. Peter D. Mosses. "Action Semantics". Cambridge University Press, 1992.
2. David A. Watt. "Programming Language Syntax and Semantics". Prentice Hall, 1991.