HandleExceptions only takes an array of exceptions, and returns Some if only one
of them is Some, None if they are all None, or raises a conflict error
otherwise.
The compilation of default terms then wraps this in a match (for the result of
HandleExceptions), and an if-then-else (for the justification-consequence in the
None case).
This avoids the complexity of having to handle thunked functions as arguments.
*Disclaimer*: This is intended for discussion
My impression is that the with-exceptions backend is to be superseded by the
without-exception backend, which is more general and more efficient. Therefore,
seeing the added complexity of maintaining the two in parallel, I see no good
reason to keep the with-exceptions version now that the equivalence of their
semantics have been proved.
It will also be nice to reduce divergences between the different backends ; and
this should make further simplifications possible (e.g. some thunkings may no
longer be needed)
Of course I am ready to hear arguments in favor of keeping it, be it in the mid-
or long-term.
This patch removes the `--avoid-exceptions` flag, making it the only option, and
the corresponding `with_exceptions` variant of the dcalc->lcalc translation. It
doesn't do further simplifications.
This includes a few separate changes:
- pass visibility information of declarations (depending on wether the
declaration was in a ```catala-metadata block or not)
- add reasonable hash computation functions to discriminate the interfaces. In
particular:
* Uids have a `hash` function that depends on their string, but not on their
actual uid (which is not stable between runs of the compiler) ; the existing
`hash` function and its uses have been renamed to `id`.
* The `Hash` module provides the tools to properly combine hashes, etc. While
we rely on `Hashtbl.hash` for the atoms, we take care not to use it on any
recursive structure (it relies on a bounded traversal).
- insert the hashes in the artefacts, and properly check and report those (for
OCaml)
**Remains to do**:
- Record and check the hashes in the other backends
- Provide a way to get stable inline-test outputs in the presence of module
hashes
- Provide a way to write external modules that don't break at every Catala
update.
- Clearly distinguish Exceptions from Errors. The only catchable exception
available in our AST is `EmptyError`, so the corresponding nodes are made less
generic, and a node `FatalError` is added
- Runtime errors are defined as a specific type in the OCaml runtime, with a
carrier exception and printing functions. These are used throughout, and
consistently by the interpreter. They always carry a position, that can be
converted to be printed with the fancy compiler location printer, or in a
simpler way from the backends.
- All operators that might be subject to an error take a position as argument,
in order to print an informative message without relying on backtraces from
the backend
--trace and --avoid-exceptions is a warning, but we want to be able to test with
the combination (in particular, api_web as forcing --trace, so we couldn't
detect its issues with exceptions).
- This adds a `catala depends` command that recursively tracks module dependency.
It can then be used by Clerk for linking.
- Generation of cmo object files are added for OCaml (we only built native
objects, but jsoo requires bytecode).
- Some fixes to the generation of value embed/deembed shims (related to types
coming from different modules ; add support for options ; etc.)
As part of making tuples first-class citizens, expliciting the arity upon
function application was needed (so that a function of two args can
transparently -- in the surface language -- be applied to either two arguments
or a pair).
It was decided to actually explicit the whole type of arguments because the cost
is the same, and this is consistent with lambda definitions.
A related change done here is the replacement of the `EOp` node for operators by
an "operator application" `EAppOp` node, enforcing a pervasive invariant that
operators are always directly applied. This makes matches terser, and highlights
the fact that the treatment of operator application is almost always different
from function application in practice.
This changes the `decl_ctx` to be toplevel only, with flattened references to
uids for most elements. The module hierarchy, which is still useful in a few
places, is kept separately.
Module names are also changed to UIDs early on, and support for module aliases
has been added (needs testing).
This resolves some issues with lookup, and should be much more robust, as well
as more convenient for most lookups.
The `decl_ctx` was also extended for string ident lookups, which avoids having
to keep the desugared resolution structure available throughout the compilation
chain.
* Obsolete code for included tests has been removed
* The engine uses a proper lexer and is much simplified
* An inline test in the middle of the file now only "sees" the file up to that
point. This fixes an issue where we had spurious errors when a type error was
added at the end of a file, and it would pop up in tests before it. This makes
files including many tests much more practical.
* diffing and resetting the tests has been reintroduced (done at the moment in
Ninja, but for more control (count number of failed tests, etc.) we could put it
back into Clerk at some point
* The Catala CLI can now take an input from stdin (with the possibility to link
a (possibly fake) on-disk file for error reporting and file locations ; this
is useful for running tests)
We need a concrete intermediate target for e.g. transitive uses of `> Include`
for Ninja to correctly handle them.
Of course we could also unroll all transitive dependencies, but meh.
Note also that now tests now just generate the outputs but facilities for
diffing and resetting are temporarily absent.
Rather than require all files to be listed on the command-line (and having to
check consistency with `> Using` directives), the main catala CLI is now a bit
more clever.
⇒ There is a new assumption that a module name definition must match the file
name (up to case and extension) — with appropriate error handling to enforce it.
In exchange, `> Using` directives are now used to more transparently lookup the
appropriate `.catala_*` interfaces and the compiled artifacts for the used modules (handling transitive dependencies), with just standard `-I` flags for when they need to be looked up in different places.
rather than scattered in structures
The context is still hierarchical for defs though, so one needs to retrieve the
path to lookup in the correct context for info. Exceptions are enums and struct
defs, which are re-exposed at toplevel.
This makes sure `catala module` finds the local runtime when run from the catala
source tree; and fixes lookup of the catala exec on custom uses of `clerk runtest`.
... and add a custom printer
Since this is a very common bug, this patch should gain us a lot of time when
debugging uncaught Not_found errors, because the element not found can now be
printed straight away without the need for further debugging.
The small cost is that one should remember to catch the correct specialised
`Foo.Map.Not_found _` exception rather than the standard `Not_found` (which
would type-check but not catch the exception). Using `find_opt` should be
preferred anyway.
Note that the other functions from the module `Map` that raise `Not_found` are
not affected ; these functions are `choose`, `min/max_binding`,
`find_first/last` which either take a predicate or fail on the empty map, so it
wouldn't make sense for them (and we probably don't use them much).
