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I'd rather be covering obscure edge cases and be complete than to limit to seemingly sane options and be inconsistent. One of the things that are very common in Object-Oriented languages is type casting. Also this doesn't introduce a new syntax.
Most validation has to happen at runtime. READY; case 400: return DeploymentStatus. A great way to tout those runtime exceptions is static type checking, so I think having TypeScript assert that would be greatly helpful. The source for this interactive example is stored in a GitHub repository. As for those constructors, I could see frequent use of BigInt. This mean that you can either use the parseInt limbo or to simply add a plus sign in from of your string. I've also got a low need for BigInt, but that's a different deal. In fact I would tend to think that having for rule that : int are always initialized and 0 by default like in other met language like ActionScript would make sense for me. Best way to convert string to a number. Also const enums should be restricted to primitive types, and the whole reason they aren't emitted is to lessen code size especially minifiedwhich would not usually be the case with other jesus, such as strings and booleans. Indeed it would make it much closer to a class but with hard restrictions : Also, i don't know if having a mutable enum entry is a good idea at all, it's the kind of thing that would get abused and would print to side-effects. Formats a number with a typescript convert string to number number of digits to the right of the decimal.
It is not possible to directly reference the Null type itself. Suppose you have the type definition for x in a. Make sure to always check for NaN values in your app to avoid surprises Plus, it retains the problem as parseInt with characters in the number: parseFloat '44. Values A double can be everything a number can be except undefined or null, including Infinity, -Infinity and NaN.
Integer & double proposal - Full support 4 Full support Yes Full support Yes Full support Yes? If you don't want value inference, then don't use it.
First, 3 is not assignable to bool, so the second assignment should definitely fail. This makes optional int parameters very dangerous, because you couldn't check them for undefined. How would you deal with that? Emit locations for 0 Can you clarify the rules for where exactly 0 would be emitted? I have to assume that the type of 1. First, 3 is not assignable to bool, so the second assignment should definitely fail. Emit locations for 0 Can you clarify the rules for where exactly 0 would be emitted? This makes optional int parameters very dangerous, because you couldn't check them for undefined. How would you deal with that? In fact I would tend to think that having for rule that : int are always initialized and 0 by default like in other typed language like ActionScript would make sense for me. Both are bad -- one introduces a floating point number into an int, and the other breaks JavaScript compatibility this is not something we would do. This one is more in line with asm. Both extends the number type. It was designed for 2 reasons, for compile time type checking and for run time optimalizations like ASM. Naming I chose for integer instead of int, because bool has been renamed to boolean in TypeScript, and integer is more in line with boolean than int. Values A double can be everything a number can be except undefined or null, including Infinity, -Infinity and NaN. An integer can be every number without a decimal point. An integer cannot be undefined, null, Infinity, -Infinity nor NaN. When you declare a variable with the type double or integer, it will automaticly be 0. Any number literal that contains no decimal point and does not have an negative exponent after the E like 9E-4 is an integer. All other number literals are doubles. The value will be converted at run time see Generated JavaScript. When converting to an integer, the number will be truncated, the numbers after the decimal point will be removed. A value that cannot be converted by truncating eg undefined or NaN to an integer will become 0. When no default value is given, 0 is used as the default value because an integer or a double cannot be undefined. Generated JavaScript Most expressions will be wrapped with... Function arguments Arguments will be reassigned according to the ASM. Typecasting A cast to double is wrapped with +... Indeed, there needs to be a rule that a non-typed variable declaration won't get the type integer or double, but always number. If you want a variable to be an integer or double, you'll need to specify that explicitly. I chose for runtime semantics to cast operations because of various reasons. For performance, js engines know better how much space they need to allocate for a number and they know which overload of the + operator is used. Integer calculations are most times faster than floating point ones. There also needs to be a way to convert the different number types between each other. If you already generate JavaScript for cast operations, why not use a cast to convert a number type? Also this doesn't introduce a new syntax. An alternative would be to write ~~ or + to convert numbers, but in my opinion the cast look better: How do you propose to deal with constants in an expression, for instance what does 1 + 2 compile to. If the constants are integers, then you'll need to insert the coercion, which will break existing TypeScript code. If you assume that they are numbers then the expression x + 1 will always be of type number. It feels to me like you need to buy into the asm. When you call add in this example with a Base and a Bar, it'll return a Foo. The + operator is overloaded the same way in my proposal. I've also got a low need for BigInt, but that's a different deal. BigInts don't interest me as much, since I rarely deal with data that large in practice. As for those constructors, I could see frequent use of BigInt. It's also a bit more verbose than I'd like, although I could live with it. I think there's a pretty natural mapping of those constructors to sized integer types, e. JavaScript finally has native integers, and ones which will raise runtime exceptions if you attempt to perform arithmetic on a mixture of BigInts and numbers. A great way to avoid those runtime exceptions is static type checking, so I think having TypeScript assert that would be greatly helpful. Suppose you have the type definition for x in a. Suppose therefore, then, that the type definition may change, without your knowledge or intent. Should your compiled emit fundamentally change, without error or warning? Suppose further that the change introduced some sort of bug. How much of a nightmare would it be to ultimately trace that bug down to a change in a. I've been cautious on suggesting any of that, since that kind of thing has been repeatedly shot down by the TS team. This may be too much syntax sugar to swallow, but the benefits outweigh the drawbacks, IMO. Should your compiled emit fundamentally change, without error or warning? So, again, for context: we're discussing integer literals. So to answer your question: yes, for untagged integer literals, there shouldn't be an error or warning even though the type changed. If you're worried about type confusion there, yes the tagged syntax should be supported to, and that should fail if a type changes from a BigInt to a number. Just let the type system be purely static checks for convenience. It can also be smart. And same for floats.