It really isn't though. PCC just walked the AST, writing out text to a file with hardly any optimizations just like most of what people call 'transpilers'. But you wouldn't call a c compiler to asm a transpiler, right? Pretty much everything that gets attributed to some intrinsic difference between source-source and source-machine compilers is just a function of the immature tooling on the web.
What I would do is ask 'what part there is any different than any other compiler?'
Why do you think it is helpful to be unambiguous between atoms that make up a human or atoms of any goods in the back of a truck? /s
> translates between programming languages that operate at approximately the same level of abstraction
That's fairly straightforward, though a bit subjective (which doesn't preclude a word from having meaning)
There's the (albeit not 100% correct) meme that C is portable PDP-11 asm. What is correct in my mind is that PCC has much fewer, much less complicated transformations to go to PDP-11 (or M68k) asm than Babel does to go from ES-next to ES5.
But for some reason Babel is a transpiler because it's all high level and that's magically different. And no one in their right mind would attempt to call the c compiler of the 1980s a transpiler.
Anyways, how is a transpiler different from a bytecode compiler, except that the bytecode is human readable?
The bytecode is human readable.
In my mind your argument is equivalent to to separating novels based on if they were written with a pen or a pencil. Yes, there's a difference between a pen and a pencil, but that has no effective bearing on the novel as written. And it doesn't make sense to categorize novels based on that.
Cfront was Bjarne's original C++ compiler. It translated C++ code into C code which would then be passed through a C compiler.
I didn't think Cfront should be called a compiler, because it didn't compile down to machine code and not even to assembly, only to another relatively high level language.
Bjarne was quite insistent that Cfront really was a compiler, and the fact that it compiled to another source language was immaterial. It did essentially the same things as any compiler, it only had a different back end code generator. And the code generator could later be swapped out for one that generates machine code.
Of course you can call it whatever you want, but Bjarne called it a compiler.
* Which I admittedly didn't make clear in the parent comments, but did mention elsewhere in this thread.