EP: 16 - HtDF Interval Data Definition

Part 16. HtDF with Interval Data Definition

We have defined the data definition for an interval, now we will make the function using HtDF recipe

The example asks us to make a function that produces true if the given seat number is an aisle

For reference, look at the interpretation of data definition, it seems that seats 1 and 32 are aisle seats.

Here we make the Signature, Purpose and Stub.

Now we make the tests, When making tests for Intervals, include the first and last value and also the midpoints. Include also test for other points of variance across the interval.

Thanks to the Data definition provided, this helped us to create our test. HtDD and HtDF are related which can help us to design our functions.

And finally, we just copy the template from the Data Definition, make sure you point that out. Comment out the stub and create the code.

The function fulfills the requirements in the problem domain. Data definitions can help us define the templates and the tests.

Mga Komento

Mga sikat na post sa blog na ito

Problem Solving using HtDF method

Problem Solving In this problem, we will use the HtDF method to create a function. Problem: Design a function that pluralizes a given word. (Pluralize means to convert the word to its plural form.) For simplicity you may assume that just adding s is enough to pluralize a word. Here is the problem that we need to convert into a function. We need to do it systematically using the HtDF method. First we need the signature, recall that the signature will tell us what is the input and expected output. A word is the input and output of the function, and we can represent words, which is just a sequence of characters if you think about it, like a String. So the signature of the function is ;;String -> String Then we will need to know what is the function's purpose, we can look at the specifications to know the purpose. It says that the word is pluralized in the process "assumption that adding s at the end is the pluralized form of the word". Ther...

Magbasa nang higit pa

EP: 18 - HtDF with Itemization

Part 18. HtDF with Itemization From the Countdown Display definition that we have made earlier, we are going to make a function out of it. We have to output an image depending on the state of the countdown. Here is the Signature, Purpose and Stub. It is recommended to run the code often, the earlier we detect bugs, the better. We need some examples. For tests on itemizations, we need to have as many tests as there are cases. Also, if we have an interval, we have to test points of variance. For the Interval, there is not much variance in the seconds before midnight so it is okay to have only one test for that. There is a primitive called text which converts text to an image, we can also use number->string to convert a number into a string datatype. Note that when we are devising tests, we are already working out the behavior of the function before we start coding. Now we get the template and start creating the function body. ...

Magbasa nang higit pa

EP: 19 - big-bang Mechanism

Part 19. big-bang We are using Dr. Racket to design interactive programs, from this day forward, this is going to be very complicated. Imagine we have 2 interactive programs, one that counts down from 10 to 0 and some animation of a cat walking in the screen. These programs are interactive by just pressing the space key, the program restarts. These interactive programs change state and it affects the program behavior. On the countdown program, it generates a number from 10 to 0 every 1 second. It is also the same with the cat program, it just changes the x coordinate of the cat every miliseconds. These are 2 different functions, now how can we combine these 2 functions. We combine them by using Dr. Rackets big-bang primitive. (big-bang 0 (on-tick next-cat) (to-draw render-cat)) We use 0 as the initial world state, then on every tick, we get the next x coordinate, we pass it to the render c...

Magbasa nang higit pa

Team Leader Mazodan

Hanapan ang Blog na Ito