% CSci 658-01: Software Language Engineering \
  Spring 2018 Assignment \#3
% **H. Conrad Cunningham**
% **5 March 2018**
 

## Revised Deadline Monday, 2 April, 2018, 11:59 p.m. 

Original deadline Thursday, 29 March, 2018, 11:59 p.m. 

## General Instructions

All homework and programming exercises must be prepared in accordance
with the instructions given in the
[Syllabus ](<../658syl_sp18.html>). Each assignment must be submitted
to your instructor by its stated deadline.

## Assignment \#3 Description

This assignment may overlap with Assignment\ #4, which likely will be a
DSL analysis and design exercise.

### Alternative A (State Machine Internal DSL)

Unless you chose an alternative problem, Assignments #1 and #2
required you to develop a *semantic model* and an *external DSL* for
Fowler's State Machine case study. You could use Python 3 or some
other appropriate language (excluding Java or Scala for which we had
solutions). You could use any of the approaches in the class materials
for designing and implementing external DSLs.
	
This alternative for Assignment #3 asks you to design and implement an
appropriate *internal DSL* for the State Machine problem in the same
programming language. You may use the semantic model you developed for
Assignment #1.

You may use any of the internal DSL techniques we have talked about in
class or that are in the Fowler DSL book. Be systematic in your use of
the DSL techniques. That is, identify what techniques you are using
and, if appropriate, how you are adapting the technique to the
programming language, problem, and DSL design. Think about design
patterns and good programmingn practices.


### Alternative B (Lair Configuration DSL)

This alternative for Assignment #3 asks you to design and implement
*one* of the following options for the Lair Configuration case
study. As above, approach the task in a systematic manner. You may use
the semantic model I provided in Python 3.
	
-   a Python 3 *internal DSL* for which I did **not** provide a
    solution (e.g., Literal Collection, Nested Function calls, etc).

-   a Python 3 *external DSL* using a different approach than I did
    for Parsita-based DSL. (Use either a different parsing technique
    or a significanly different syntax).


### Alternative C (Sandwich DSL)

This alternative for Assignment #3 asks you to design and implement
*one* of the following options related to the Sandwich DSL case study.
As above, approach the task in a systematic manner.  You will need to
implement an appropriate semantic model.

-   a Python 3 *internal* DSL 

-   a Python 3 *external* DSL 

The class lecture notes give solutions in Haskell, Scala, and Lua,
with the older Lua problem description being slightly different.


### Alternative D (Choose Your Own Adventure)

Investigate use of  the following:

-  a Python 3 parser generator library (e.g., Arpeggio/textX)

-  a different parser combinator library (e.g., Parsy) than the one I
   used. 
   
Then design and implement an *external* DSL for the (a) State Machine,
(b) Lair Configuration, or (c) Sandwich DSL case studies. For the
State Machine you may use your semantic model from Assignments 1
and 2. For the Lair Configuration, you may use my semantic model from
class.


## For All Alternatives

-   When complete, submit your source code, test DSL input, test
    program, etc. files to Blackboard.
	
-   Be sure to describe your DSL's syntax and give instructions on how
    to build your program from the source code.
	
-   Remember that the instructor prefers to compile and execute your
    solution on his MacOS systems. Make it easy for him by identifying
    what software is needed, etc.

-   This is an individual assignment. Document what resources you used
    in constructing your solution.


### Looking Ahead

-   Assignment #4 will likely be a group DSL analysis and design
    exercise for a problem. (I am considering using a text-based,
    choose-your-own-adventure game as the problem.)
	
-   Finally, you will need to complete a project in which you choose
    your own problem and then design an implement a DSL to solve it.
    You are encouraged to choose something of interest to your
    research or professional goals or something else interesting.