EP: 17 - HtDF with Enumeration

Part 17. HTDF with Enumeration

In this example, We will be devising a function that gets the grade and bumps it to the next highest grade.

Interesting thing about data definitions is that you do not have to make a data definition for each function. A data definition for that set of data can be reusable for any function that takes it as an input.

Here we will define the signature, purpose and stub. Note that there is no grade above A. We will have to decide what happens to it. For now, there would be no change if we hit the highest grade.

We need some examples. In enumerations, we should at least have as many tests as the total number of cases.

We have 3 cases as defined by the definition. So we should have 3 tests.

We can copy the template from the definition. This makes it easier.

Note. The template must not contain any errors, this will affect our code when we implement them.

Do not forget to change the template name to the actual function name

Run it and the tests should pass.

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EP: 18 - HtDF with Itemization

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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...

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EP: 15 - Itemization Data Definition

Part 15. Itemization Data Definition The Itemization Data Definition is what we use for information compromised of 2 different categories, at least one of each is not a distinct value. This data definition is quite complex. As an example: Design a data definition for the current state of the countdown for the display, which falls in one of 3 categories. Not yet started from 10 to 1 seconds until midnight Complete This is like the countdown clock in TV. By looking at these states, the second one is not a distinct data value. Therefore this is not an enumeration. In this case, we will use the Itemization Data Definition. We have to choose a datatype that fulfills the categories. For someone that has done strict programming style method for a long time now, Data consisting of multiple data types confuse my brain, but I think Lisp Based languages tend to be liberal about the types of parameters unlike the C family or it's influences. This is one of the thing that lisp ...

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