New feature: string interpolation

[Sasino97]

It would be nice to add support for direct string interpolation in Teal.

This:

local val: number = 15.5
print($"value is {val}")

Would be compiled into this:

local val = 15.5
print(string.format("value is %f", val))

Of course, if you don't like the C#-like syntax above feel free to change it, but in general being able to do that is great for readability.

EDIT

I wanna add that since Teal is able to detect types, it would be easy for the compiler to choose between %s, %d, %f and so on.

For things like formatting, e.g. %0.2f or %04d, it would be nice to specify the format inside of the brackets, e.g. $"value is {val:0.2}" (compiled into string.format("value is %0.2f", val)).

Also overriding the whole type should be possible by adding the f/d/s... at the end, like $"value is {val:04d}" (compiled into string.format("value is %04d", val)), ignoring whether val is actually an integer or something else.

[Frityet]

@Sasino97 Might be a better thing to implement with macros. Already you can do pretty good string interp