How Lang does
conversion to C or Lisp
Lang has a reader, reading trees with the symbols, a
resolver, which resolves all the types from constants
specification by the user and function overloading. This
little article is about what follows, converting to C, or
Lisp. (Or anything else)
From that last one one also, of course wants to convert to
something that can actually execute. I used to have a rather
ugly function to convert to C directly. The problem with
that is that C does not have higher order functions or
bodies inside function arguments.
The older solution solved that in the conversion itself,
which is probably why it stunk so much. The newer version
works differently; it uses conversion functions that can
only convert a subset of Lang.
However, i add transformations that change Lang code such
that it is in those subsets. That way, if i want to add
conversions to other languages, it should be easy, unless
the language a smaller subset then previously encountered.
In that case, i would have to make another transformation. I
might be overconfident here, though.
Note that it is still very incomplete, no higher order
functions yet. Making a transformation to that subset for C
might be tricky, for conversion to Common Lisp it isn't a
Another thing that i didn't do yet is types for the common
lisp version. First, i am planning to express number types
like this: (integer from to) and (number from to), that
would work with lisp better. (I also want to keep C-like
number treatment though.)
This principle, and the code might well be able to convert
Common Lisp to other stuff as wel, i guess i don't have to
worry that this work is useless if the Lang project fails.