How to convert types with EmojiCode

[Henry Saba]

Emojicode newbie here.

How does one convert:
🔤123🔤 ➡️ test
Into an integer?

Probably best to teach a new Emojicoder "how to fish." I do see this in the docs:

🔢❗️
❗️ 🔢 base 🔢 ➡️ 🍬🔢
This methods tries to construct an integer from this string in the given base. It returns the integer or no value if the string does not match the regular expression [+-]?[0-9a-zA-Z]+ or it does not represent a valid value in the given base.

...but many failed attempts have showed me that I do not yet know how interpret that "declaration." Any help here would be appreciated. Thanks.

[thbwd]

Have you read https://www.emojicode.org/docs/reference/classes-valuetypes.html?

[Joe Skeen]

Don't worry, jumping into Emojicode can be a bit overwhelming. Let me try to teach you how to fish.

When you have a string 🔤123🔤 it is an instance of the class 🔡. That class is documented here: https://www.emojicode.org/docs/packages/s/1f521.html

The 🔡 class has an instance member 🔢❗️ defined here: https://www.emojicode.org/docs/packages/s/1f521.html#s.class_1f521.1f522-s.vt_1f522. This instance method of the string class converts the value into an integer.

• 🔢 is the name of the method, which in this case just happens to also be the same emoji used as the name of the integer value type.
• ❗️is the mood of the method, in this case imperative.

In general, you will call a method using the instance of that class, in your case, to call 🔢❗️ on the test variable of type 🔡, you would do this: 🔢 test❗️. This is the equivalent of doing something like test.toInteger() in another language. One snag, 🔢 test❗️ doesn't actually work, because the 🔢❗️ method takes a parameter base of type 🔢:

DECLARATION
❗️ 🔢  base 🔢 ➡️ 🍬🔢

So in addition to providing the class instance, you also have to provide all the required parameters. The parameters are space-separated after the instance, so to convert it to an integer treating the string as a base-10 value, you would call it as so: 🔢 test 10❗️.

🔤123🔤 ➡️ test 
🔢test 10❗ ➡️ testAsInt

Now that you know how to call the method, you need to understand what it's returning. If you look again at the declaration, it says it returns (➡️) a value of type 🍬🔢. This can be read as "an optional of type integer". There is a good guide on Optional types here: https://www.emojicode.org/docs/reference/optionals.html. Basically what we need to know here is this:

• an optional may be equal to 🤷 (null)
• if you know it's not 🤷, you can unwrap the optional using 🍺

You will likely need to decide what to do if the parsing doesn't work, whether it is throwing an error, or writing a message to the user. Let's write an if statement:

🔢test 10❗ ➡️ intValueMaybe

↪️ intValueMaybe 🙌 🤷 🍇
    😀 🔤the value "🧲test🧲" didn't successfully convert to an integer🔤 ❗
🍉 🙅 🍇
    🍺intValueMaybe ➡️ intValue 
    😀 🔤successfully parsed to integer: 🧲 intValue 🧲🔤 ❗
🍉

If you want to make this code reusable you need to wrap it in a class. Here is my final working code:

🏁 🍇
    🆕🔰 ❗ ➡️ instance

    🌯instance 🔤123🔤❗
    🌯instance 🔤one two three🔤❗
🍉

🐇 🔰 🍇
    🆕 🍇🍉

    📗 
        Tries to convert the value into a 🔢. If it succeeds, it prints it out;
        otherwise prints a message that it wasn't a valid integer.
    📗
    ❗ 🌯 stringValue🔡 🍇
        🔢stringValue 10❗ ➡️ intValue

        ↪️ intValue 🙌 🤷 🍇
            😀 🔤the value "🧲stringValue🧲" didn't successfully convert to an integer🔤 ❗
        🍉 🙅 🍇
            😀 🔤🧲 🍺intValue 🧲🔤 ❗
        🍉
    🍉
🍉

Running this should yield the result:

123
the value "one two three" didn't successfully convert to an integer

Hope this makes sense and gets you more comfortable with some of the fundamentals of Emojicode. It's really a fun language once you get the hang of it.

[thbwd]

@joeskeen Thanks for providing this wonderful explanation!

[Henry Saba]

WOW! Thanks to both of you! Is there a better location for me to interact more with the Emojicode community?

[Joe Skeen]

https://gitter.im/emojicode/emojicode