Unary negation operator

[betseg]

✏️ Proposed change

Adding a new operator for negating an expression. I'm thinking of 🔃, because positive values are above the negative ones, and this emoji is vertical.

🤔 Rationale

It's useful 🤷

🕺Example

🍦 a 3
🍦 b 🔃a
↪️ 😛 b -3

or

🍦 a 3
🍦 b 🔃a
↪️ 😛 b 🔃3

[thbwd]

I think ➖ is more intuitive. In 0.6 binary operators are infix anyway, so this should work just fine:

3 ➡️ a
➖a ➡️ b
↪️ b 🙌 -3 🍇 💭...

[betseg]

yeh forgot that, nice.

also, ➖3 🙌 -3?

[thbwd]

➖3 🙌 -3 Yep.

[thbwd]

➖ is actually not possible – I realised when I first tried to implement this – because it is ambiguous. For instance:

🤭 10 ➖4❗️

Is this a method call on 10 with one argument or on 6 with no arguments?

We need to reconsider alternatives. The original 🔃 might not be optimal as it is very similar to 🔁, which is a flow control statement but not an operator.

[Daniel]

Why do you need a new operator in the first place? Why don't the minus sign work?
In every other languages I know of, you use the minus sign for this.

In Java, these two lines gives the same result:
a = 0 - b;
a = -b;

[thbwd]

As I stated before, it’s ambiguous. Technically it is possible, of course, but it probably isn't what you'd expect.

The lines you showed work in Emojicode just as well, but Java has a completely different call syntax than Java, that does not allow the ambiguity seen above:

10.beQuiet(-4)
// or
(10 -4).beQuiet(4)

[betseg]

🔋 because batteries have a positive and a negative side? Or 🧲 because magnets have a north and a south poles?

[thbwd]

@betseg Valid options, but I don’t think these are very clear for something as simple as this.

Giving this a second thought, we could solve the above problem with 🤜🤛 in cases like this:

🤭 10 🤜➖4🤛❗️

But maybe this is overly verbose.

[thbwd]

Since 🤜➖4🤛 would still require a substantial amount of the changes to the grammar, I’ll go with @betseg’s suggestion of 🔋. The + and - on the battery do make some sense and it’s important we finally resolve this.