This section will document any updates applied to the project since original release:

• Clarification: in append(), you do not have to make use of getpos()/setpos() as the instructions otherwise indicate. That's a leftover comment when I copied it from insert(). So, do not feel compelled to use them on append() (really, you don't need to).
• revision #: <description> (DATESTRING)

We've commenced on our list explorations, implementing some of the core functionality (adding nodes to a list through insertion) as well as some helper functionality to make our list transactions even more effective (creating, displaying, getting node positions, and setting node positions).

In this project, we continue our list implementation by exploring the appending of nodes to a list, searching for nodes within a list, copying a list, displaying a list in reverse, and comparing two lists for equality.

In inc/ is the list header file: list.h

For this project, we're going to be implementing the following functions:

List *append(List *, Node *, Node *);   // append new node into list after specified place
Node *searchlist(List *, char);         // is there a node containing value in list?
List *cplist(List *);                   // duplicate existing list
void  displayb(List *, int);            // display list backwards
uc    compare(List *, List *, ulli *);  // compare two lists for equality

Additionally, the following content has been added, largely to aid with compare() implementation and operation:

typedef struct list            List;    // because we deserve nice things
typedef unsigned long long int ulli;    // short name for biggest space
typedef unsigned char          uc;      // shorter name for smallest space

and:

// return status codes
//
#define CMP_EQUALITY    0x00
#define CMP_L1_NULL     0x01
#define CMP_L1_EMPTY    0x02
#define CMP_L1_GREATER  0x04
#define CMP_L1_LESS     0x08
#define CMP_L2_NULL     0x10
#define CMP_L2_EMPTY    0x20
#define CMP_L2_GREATER  0x40
#define CMP_L2_LESS     0x80

As a suggestion, I'd recommend implementing them in the order listed above, starting with append() and then searchlist(). By doing this, you get to review a bit from the previous weeks before you continue with base functionality, which will help you in your implementation of the other functions.

An important perspective to keep when implementing these list functions is to be mindful of what functionality can be a unit of something else. Do not reinvent the wheel- utilize functions you've written- it will shorten your code, and reduce the chance of error. Plus, that IS the intent.. to have each function be specific and focused on its particular task; to do one thing, and do that one thing extremely well. We can then use them as base units to build more sophisticated functionality.

In this project, append() can be considered that basic operation, where cplist() can be built using append() (along with any other list/node functions from this and previous projects).

In src/list/, you will find 5 new C files:

• append.c - which will house the append function
• cp.c - which will house the list copy function
• search.c - which will house the list search function
• displayb.c - which will handle displaying the list backwards
• compare.c - which will handle comparing two lists for equality

Take a look at the code there. These are the files that contain functions which will be compiled and archived into the list library (liblist.a) we will be using in this and future projects.

Figure out what is going on, make sure you understand it.

NOTE: None of these files denote an entire runnable program. These are merely standalone functions. The various programs under the unit/ and app/ directories will use these functions in addition to their application logic to create complete executable programs.

You will also notice there are function prototypes for these list library functions in the list.h header file, located in the inc/ subdirectory, which you'll notice all the related programs you'll be playing with in this project are #includeing.

In unit/list/, you will find these new files:

• unit-append.c - unit test for append() library function
• unit-cplist.c - unit test for cplist() library function
• unit-searchlist.c - unit test for searchlist() library function
• unit-displayb.c - unit test for displayb() library function
• unit-compare.c - unit test for compare() library function

These are complete runnable programs (when compiled, and linked against the list library, which is all handled for you by the Makefile system in place).

Of particular importance, I want you to take a close look at:

• the source code to each of these unit tests
  • the purpose of these programs is to validate the correct functionality of the respective library functions
  • follow the logic
  • make sure you understand what is going on
  • ask questions to get clarification!
• the output from these programs once compiled and ran
  • analyze the output
  • make sure you understand what is going on
  • ask questions to get clarification!

To assist you in verifying a correct implementation, a fully working implementation of the node library and list library (up to this point) should resemble the following:

Here is what you should get for all the functions completed so far in the list library (sll0+sll1):

lab46:~/src/data/sll1$ bin/verify-list.sh
======================================================
=     Verifying Singly-Linked List Functionality     =
======================================================
    [mklist] Total:   5, Matches:   5, Mismatches:   0
    [insert] Total:  11, Matches:  11, Mismatches:   0
  [displayf] Total:  10, Matches:  10, Mismatches:   0
    [getpos] Total:   8, Matches:   8, Mismatches:   0
    [setpos] Total:   9, Matches:   9, Mismatches:   0
    [append] Total:  11, Matches:  11, Mismatches:   0
[searchlist] Total:  11, Matches:  11, Mismatches:   0
    [cplist] Total:  11, Matches:  11, Mismatches:   0
  [displayb] Total:  10, Matches:  10, Mismatches:   0
   [compare] Total:  15, Matches:  15, Mismatches:   0
======================================================
   [RESULTS] Total: 101, Matches: 101, Mismatches:   0
======================================================
lab46:~/src/data/sll1$