Re: [9fans] Replacements for lex

["Bruce Ellis" <bruce.ellis@gmail.com>]

I taught a course in advanced compiler construction where the
students were required to write a lisp interpreter in C and then
write a rudimentry C compiler in their lisp.

The "bits you don't have to do" included the c lex function which
was presented to them in lisp as a (c:token) function.  I've written
a lot of lex-ers and it was just the same code again (in c) which
stopped the students from spending all of their time trying to do
the same in lisp.  This enabled them to concentrate on the more
interesting tasks (I also supplied the lisp alloc and gc code).

It was a fun course and I hope things were learnt.

For most stuff something like lex is fine.  Have a try at getting
<integer/float constant> reg-exp useable and I'll type in a lex-er
faster than you can debug the reg-exps (a chore i decided was
a waste of time for the course).

brucee

On 1/20/07, William Josephson <jkw@eecs.harvard.edu> wrote:
> On Fri, Jan 19, 2007 at 02:26:47PM -0500, Joel Salomon wrote:
> > >I think that most people roll their own lexical analyzers under Plan 9.
> > >That's typically not too hard to do, though.
> >
> > That's likely what I'll do for the final project (probably yet another
> > C complier, but I might try my hand with [a subset of] D), but the
>
> You'll learn a lot more if you don't try anything like C
> let alone C++ or D.  For a semester-length project, you'll
> learn far more if you work on a much smaller language --
> ideally domain specific, in my opinion -- and really see it
> through in detail.
>