Computer Organization

1
Computer Organization

• Project 4
• Prof. Jerry Breecher
• CSCI 140
• Spring 2005

2
What You Will Do In This Project

• The purpose of this project is to take the next
  steps in writing a more complex program.
• You are working toward writing a program that can
  take in the following input
• ADQltwsgtstring1ltwsgt.ltwsgtstringN
• Where
• ADQ means Sort in Ascending order, Descending
  order or Quit.
• ltwsgt whitespace space or tab.
• There is a considerable amount of work to do
  here, and so it makes sense to divide this into
  smaller pieces.
• Project 3 Handling arbitrary number of strings.
• Project 4 Parsing a long string looking for
  arbitrary characters.
• Project 5 Putting it all together.

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What You Will Do In This Project

• This week in more detail.
• A really difficult task in any language is to
  parse a string of characters looking for
  particular patterns. In this case a pattern is
  easy looking for one of several characters.
• And when you find these patterns, you must take
  the action of splitting the string youre
  searching on into a number of smaller strings.
• As always, getting your head around the code is
  the hardest part of the job. And so we require
  good coding techniques to do this task.

4
What You Will Do In This Project

• Groundrules
• Credit for Projects
• Is based on deliverables.
• You will be expected to e-mail me a High Level
  Design Program AND a test plan by noon on
  Thursday.
• You will be expected to do a Show and Tell one
  week after the project is assigned. See the
  evaluation sheet.
• You will also be expected to turn in your
  assignment, placing it in the CS140 submissions
  directory. To do this, name your completed code
  as proj4.s, and then from the directory in which
  the code currently resides, type the following
• jbreecher/turnin.pl 140 proj4.s

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What You Will Do In This Project

• LookForDelimiters
• Writing the interfaces and specs for routines
  goes a long way toward breaking up the project.
  One way to do this is to define the routine
  look_for_delimiters with the following interface
• 
  
• look_for_delimiters
• Inputs
• a0 - contains the address of the
  delimiter string.
• a1 - contains the address of the start
  of the string to be parsed.
• The delimiter string has the following
  properties
• lt0 or more characters that are
  delimitersgtltThe NL chargtlt0gt
• The string to be parsed has the following
  properties
• lt0 or more characters, some of which
  MAY be delimitersgtltThe NL chargtlt0gt

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What You Will Do In This Project

• LookForDelimiters
• Heres the continuation of the interface spec.
• Outputs
• a0 (unmodified) - contains the address
  of the delimiter string.
• a1 (unmodified) - contains the address
  of the start of the string that was parsed.
• v0 - A pointer to the location in the
  parsed string where a delimiter was found.
• v1 The delimiter character that was
  found.
• 
  

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What You Will Do In This Project

• So the interface for the next part of the
  assignment will look like this
• What are the delimiter(s) CEF
• What is the String To Parse Now iCeciclEs
  Descend From thE sky
• Result
• Now i
• ecicl
• s Descend
• rom th
• sky
• What are the delimiter(s)

The string of characters between each of the
delimiters is printed out.
8
A Test Plan

• Here are some possible inputs that you can check
  for. I have attempted to give you some
  interesting and unusual conditions. You will
  want to continue this test plan to find other
  possible cases.

9
Project 4 Evaluation Sheet

• Name____________________________________________
  _____________
•  
• Is there a complete set of test cases?
•  
•  
• Is there functioning High Level Language Program
  emulating this Assignment? Do the test cases
  given work on this program?
•  
•  
• Does the MIPS program work as expected on student
  test cases?
•  
•  
• Does the MIPS program work as expected on
  professor test cases?
•  
•  
• Is the code organized as a set of functions
  rather than as one big chunk of main code?
•  
•  
• Is the code readable and well commented?
•