iansjack wrote:
Compilers, assemblers, and text editors already exist and can be ported to a new OS with little real effort. As for the OS described, it took Thompson about a month to write a more powerful OS than described here, complete with assembler and text editor.
Three decades seems a little long for such a simple system.
Three decades seems a little long for such a simple system.
Thompson didn't write the compiler. He modified the BCPL interpreter to have a syntax he liked, he and his colleagues realized they wanted more than one type and compilation would be nice, then Dennis Ritchie wrote the C compiler. I don't know how this sequence of events relates with writing the initial, assembly-language version of Unix, but I'm pretty sure they started writing Unix in 1969 and weren't finished until some point in 1970.
@kerravon: I think your full C90 support makes your C standard library much more complex than the original C of 1970 or so. I'm sure it's much easier to make a simple C without worrying about compatibility. And there's the question of how much energy different devs have for coding after the other activities in their life. Someone who codes for a living might take 10 years to get their OS into a good state even when using gcc and glibc, (we used to quote that figure all the time,) but once, some guy holed up in a cabin in the woods with nothing but laptops for company produced a GUI OS in 5 months.
As for the compiler, I'm told recursive descent parsers are very easy to write. I wouldn't know. I'm going for Forth because many people have done exactly what @flossy would like to, but with Forth instead of C. It's supposed to be relatively easy to make a Forth compiler, but my brain keeps getting tripped up over the indirection in the one tutorial I've looked at -- JonesForth. I'm looking at hForth now; small, simple, designed for embedded work and public domain. Lots of Forths are public domain. Perhaps that's because it had a very different niche to C.