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--- haas:fall2014:data:projects:node1 [2014/09/21 21:19] – [Your task] wedge
+++ haas:fall2014:data:projects:node1 [2014/09/21 22:02] (current) – [node library] wedge
@@ Line 187: / Line 187: @@
 As such, it is most advisable to have completed work on **node1** before upgrading to the **sll0** project, so any work you've done will be immediately available to build upon in the next project (the projects will be comprehensive to one another-- **sll0** will rely on work completed in **node1**, **sll1** (the project after **sll0**) will rely on the work done in **sll0**, etc.).
-=====Project Operation=====
+=====Project Overview=====
-In **testing/node/app/**, you will find a file called: **node-app-display.c**
-Take a look at the code already there. Figure out what is going on, make sure you understand it. It builds a list of nodes based on user input.
+====node library====
+In **src/node/**, you will find 3 new files: **mk.c**, **cp.c**, and **rm.c** (along with a **Makefile**)
-If you look at the bottom of the program, you'll see the following comment:
+Take a look at the code there. These are the files that contain functions which will be compiled and archived into the node library (**libnode.a**) we will be using in this and future projects.
+Figure out what is going on, make sure you understand it.
+There are 3 functions in the node library:
+  * **mknode()** - creates and initializes a new node, eliminating your need to manually run **malloc()** for new nodes
+  * **cpnode()** - duplicates an existing node
+  * **rmnode()** - removes/deallocates (frees the memory allocated to) a node
+None of these files denote an entire runnable program. These are merely standalone functions. The various programs under the **testing/** directory 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 node library functions in the **node.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 **#include**ing.
+The prototypes (taken right from **inc/node.h** are as follows:
 <code c>
-    // Display list from start to end
+Node *mknode(int   );     // allocate new node containing value
+Node *rmnode(Node *);     // deallocate node
+Node *cpnode(Node *);     // duplicate node
 </code>
-It is here I would like for you to add code that will display the contents of this arbitrary list of nodes, from beginning to end.
+This is your API for the node library. In order to use the node library three things need to happen:
+  * you must **#include "node.h"** (generally already done you in this project)
+  * you must link against **lib/libnode.a** (the Makefiles take care of this for you)
+  * you must call the functions providing the appropriate arguments and handling the return values
+In general, this is no different than what you've already done, each and every time you've used **printf()**, **scanf()**, **atoi()**, **sqrt()**, etc. Only until now, you haven't actually had the code  right in front of you. But these functions all work the same way, these conditions have to be met for them to operate and be used.
+The compiler does a lot of behind-the-scenes work (linking against the C standard library by default, so all you have to do is include **stdio.h** and/or **stdlib.h**).
+If you've ever played with the math library, you've had a slightly closer look, as such code wouldn't compile with only an include of **math.h**, you also needed to add a **-lm** on the compiler command-line.
+Again, same details apply here, only the Makefile system automates the library linking. All we have to do is **#include** the appropriate files.
+====Node library unit tests====
+In **testing/node/unit/**, you will find 3 files (along with a **Makefile**):
+  * **unit-cpnode.c** - unit test for **cpnode()** library function
+  * **unit-mknode.c** - unit test for **mknode()** library function
+  * **unit-rmnode.c** - unit test for **rmnode()** library function
+These are complete runnable programs (when compiled, and linked against the node 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!
+====Node application programs====
+Once again we find ourselves in **testing/node/app/**, which still has the programs from the previous project (**node0**). But you should notice some new files as well:
+  * **node-app-arrtolist.c**
+  * **node-app-display2.c**
+  * **node-app-test3.c**
+Take a look at these new additions. Your task for this project will involve implementing requested functionality/completing these programs.
 ====Building the code====
 You've made changes to **node-app-display2.c**, and are ready to see your results. What do we do?
@@ Line 253: / Line 309: @@
 ====Run the program====
-To run **node-app-display**, we'd do the following (specify a relative path to the executable):
+To run **node-app-display2**, we'd do the following (specify a relative path to the executable):
 <cli>
@@ Line 282: / Line 338: @@
 ======Your task======
-You are specifically responsible for creating this line of output:
+This project has you making changes to 3 files, all in the **testing/node/app/** directory:
+  * **node-app-arrtolist.c** - convert an existing array to a linked list
+  * **node-app-display2.c**  - rewrite the list-building logic using a do-while loop
+  * **node-app-test3.c**     - rewrite **-test2** using node library functions
+In addition to the stated tasks, you are to convert the code in these 3 programs to use node library functions (i.e. once complete, you should no longer be calling **malloc()** to create new nodes, and you shouldn't be initializing node values to 0 or setting initial next pointers to NULL-- let the node library functions do that for you).
+=====node-app-test3=====
+A big aspect of the **node0** and **node1** projects is to get you acclimated to the overall structure of the project organization, and to make use of library functions created to facilitate our on-going explorations.
+So, along that path, your task with **node-app-test3** is to re-implement the functionality of **node-app-test2** (previously provided as a complete running program in the **node0** project), and to convert it over to using node library functions.
+That means:
+  * no more explicit **malloc()** calls, value initializations to 0, initial next pointers to NULL; use **mknode()** instead
+  * use of **cpnode()** where you have instances of duplicated nodes (this DOES happen in **node-app-test2**.
+You are to get a program that produces the same functional output (obviously with different displayed addresses), by using the node library and its functions.
+The skeleton is there, you just need to adapt the code.
+=====node-app-arrtolist=====
+As a means of testing your understanding, this program sets up a pre-existing array, filled with values, and displays it to STDOUT.
+Your task is to add in logic that builds a list, one node at a time, containing the same values (and in the same order) as is found in that array, and to then display the linked list to STDOUT, where we should see identical information.
+Sample output of completed code should look like:
 <cli>
- -> 17 -> 23 -> 4 -> 56 -> 2 -> NULL
+lab46:~/src/data/node1/bin$ ./node-app-arrtolist
+Array: 3 1 4 1 5 9 2 6 5 3 5 8 9 7
+List:  3 1 4 1 5 9 2 6 5 3 5 8 9 7
+lab46:~/src/data/node1/bin$
 </cli>
-It needs to work for whatever values are put in the list (which can range from 0 to infinite values).
+As the array is defined with set values, your output, when complete and correct, should always be the same. This tends to be a good exercise in demonstrating you understand conceptually what is going on and can perform the necessary node manipulations to pull it off.
+Again, be sure to use node library functions (like **mknode()**) in this program.
+=====node-app-display2=====
+In the **node0** project we had to implement the display functionality for the list being built.
+Here, we work with that same idea, only we change a few things around structurally in the program- the final output should still be the same, but the code to produce it will be different.
+Basically, there are three items for you to address:
-You need to display the node's contents, and separate that from the next bit of information with a space separated "->", to help show the continuity of nodes we've joined together.
+  * convert your raw **malloc()** calls and node initializations to **mknode()** calls. There should be 0 instances of **malloc()** in your final code.
+  * switch the main driving loop that builds the list to a **do-while** (the previous version used a **while**). But you're aiming for the same end result.
+    * your display functionality can remain a **while**
+  * move your display code into a dedicated **display()** function, which takes as a parameter a Node pointer pointing to the preferred beginning of the list you'd like to display.
+    * This starts warming us up to future projects, where we'll be using and calling lots of functions
-Finally, when you have exhausted your list, display a terminating "NULL" to visually signify the completion of the task.
+The output should be the same as experienced in **node-app-display**, the first version of the program, as you had to complete in the **node0** project.
 =====Submission Criteria=====
@@ Line 298: / Line 397: @@
   * Code must compile cleanly (no warnings or errors)
+    * **node-app-test3**, **node-app-arrtolist**, and **node-app-display2**
   * Executed programs must display in a manner similar to provided output
   * Processing must be correct based on input given and output requested

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