Re: Bart's Language

On 18/03/2025 15:10, Waldek Hebisch wrote:

bart <bc@freeuk.com> wrote:

On 18/03/2025 12:17, Waldek Hebisch wrote:

There were some tweaks needed; it indicates some basic info missing from
my write-up! (For example, that the function call needs to be bar() not
bar; 'const' is only for compile-time expressions; and that C's 'const'
doesn't exist - it only briefly mentions an attempt at 'let'.)
>
The revised code is shown below, with what I assumed were your
intentions.

 Well, my intentions beter correspond to the C version below:
 int foo() {
     const int c = c1(10);
     const int b = c + c2(2);
     const int a = b+c3(c);
     bar();
     baz();
     return c;
}
 Part of the question was if "execution" of declarations is
interleaved with execution of code or if declarations go
before the code.

A declaration like:
    int a := x
can be considered to be:
    int a; a := x
where the declaration can go anywhere in the scope=, but the assignment must be done here. There are languages where you have:
     print x
     where x is ...
But the typical usage pattern in my own programs is that local variable are declared before first use.
(Maybe a compiler option can enforce that, but I don't see it as critical.)

      print a
      int a:=100
>
the assignment is done at that place in the code (after print), but the
scope of 'a' is function-wide. My compiler doesn't detect accesses to
unitialised variables, but I could add a debug option to clear
stack-frame variables on function entry.)

 I see.  So your feature conflicts with C feature "variable which is
initialized at declaration time is always used initialized".

That doesn't happen here:
   int a = a;
gcc (with no extra options) tcc and bcc both put some undefined value in a.
gcc won't warn until you say '-Wextra', and then only for:
   int a = a + 1;