A collection of additional Carbon examples demonstrating current
language capabilities and some limitations of the current state of the
toolchain.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
In order to support these examples, this adds two new builtins to the
toolchain: `print.char` and `read.char`, which map to the libc functions
`putchar` and `getchar`.
Instead of treating `Core.Int` as the toolchain's builtin `IntType`,
model it as a class that adapts the builtin type. This aligns us better
with the intended language model, gives an associated library for
`impl`s involving `Core.Int` to live within, and opens the door adding
member functions to `Core.Int` if we decide that is desirable.
Remarkably it also seems to make the formatted SemIR a little smaller,
because a call to a generic class generates less IR than a call to a
function.
When an `IntLiteral` appears as an operand of an `if` expression,
convert it to `i32` for now, so that we don't reject things like `if
cond then 1 else 2` due to having a non-constant value of type
`IntLiteral`.
For tuple indexing expressions such as `(a, b).0`, convert the index to
type `IntLiteral`, not to type `i32`. This isn't strictly necessary to
do in this PR, but avoids the need to provide an `IntLiteral` -> `i32`
implicit conversion for `no_prelude` tests using this syntax.
We'd been discussing that explorer remains necessary for print, and I
was wondering if this kind of approach would be okay (we _probably_ want
this to work, based on #2110, albeit with more overloads -- but I don't
think there's a good way to support overloads at the moment).
```
╚╡../bazel-bin/examples/sieve
2
3
5
7
11
13
17
19
23
29
31
37
41
43
...
```
Note, I assume this doesn't affect all the TODOs (like for i32.carbon),
but does cut some things down (and requires updating some tests that
have prelude name conflicts, but I think they were intended to be
updated this way).
The driver now looks for all files under core/prelude/ and considers
them all to be part of the prelude. The driver also now only processes
the prelude in `--phase=check` and later, when it would actually be
imported.
With that done, add a simple `carbon_binary` build rule and use it to
build the example in `//examples`. This should cause the example to be
built as part of our continuous integration.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Move completeness check to the point where the function is defined or
first called. This means we also defer deciding whether the function has
a return slot until that point. Instead of storing a return slot per
function, store the location of the return storage, which may or may not
be used, and compute and store a separate flag saying whether to use it
at the point of first use or definition.
This is the final piece in supporting simple `Make` functions in classes
as a replacement for constructors.
Split apart the interfaces into separate libraries by theme. We don't
yet have a way to re-export them, so for now change importers to use the
fine-grained names.
This is almost certainly not how we'll want these to be organized, and
if the examples/ directory is kept it should have BUILD files. But this
at least lets me park these files somewhere that's more global than my
own checkout.
Richard SmithandJon Ross-Perkins
josh11bandJosh L