TS seems like a great choice syntactically for WASM because it’s familiar to developers who are writing WASM, ie frontend programmers. Compared to rust WASM, this seems to be much better for on boarding.
However, because it’s not actually compiling to JavaScript like typescript is normally, this means there must be quirks and differences that must be understood to solve harder problems. Depending on how friendly the compiler is, this can be very painful or intuitive.
I’m guessing it’s infeasible to compile TS to WASM since they’re targeting very different outputs - a ahead of time, dynamic weakly typed scripting language can’t possibly be compatible with an ahead of time, strongly typed, binary output.
And if someone tells you it is, I suspect they’re doing a lot of magic that’s hiding problems that only become obvious after writing nontrivial programs.
I think the developer base still remains to be seen. As long as WebAssembly doesn't provide significant speedups over tuned JS, it seems likely we'll continue to mostly see it used for porting code from platforms and languages that don't natively target the web.
On Firefix and Safari we have the same missing optimizations. Basically wasm in all browsers reuse the same codegen from JS. But this will improved in the future.
Also, don't forget about SIMD, multi-threading with stared buffers and atomics and multi-values, a lot of special instructions like popcnt, ctz, clz, rotl/rotr and etc which not supported by JS and usually emulate not in the best way that complicates or make impossible to optimize this by the JS compiler.
In some points JS is really fast, so much that it is not inferior, for example, to the C language with the LLVM compiler without vectorization (-O2). Obviously
WebAssembly can't outperform JS in such cases.
However, because it’s not actually compiling to JavaScript like typescript is normally, this means there must be quirks and differences that must be understood to solve harder problems. Depending on how friendly the compiler is, this can be very painful or intuitive.
I’m guessing it’s infeasible to compile TS to WASM since they’re targeting very different outputs - a ahead of time, dynamic weakly typed scripting language can’t possibly be compatible with an ahead of time, strongly typed, binary output.
And if someone tells you it is, I suspect they’re doing a lot of magic that’s hiding problems that only become obvious after writing nontrivial programs.