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.
The way nested priorities are encoded use `< < excs | true :- nested > :- x >`,
which imply that `nested` can actually be ∅ ; to cope with this, the typing of
default terms is made more generic (the return type is now the same as the
`cons` type `'a`, rather than `<'a>`). For the general case, we add an explicit
`EPureDefault` node which just encapsulates its argument (a `return`, in monad
terminology).
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 patch functorises the generic expression printer, in order to be able to
re-use it for end-user printing.
It makes it possible to have an end-user, localised printer that shares the code
for e.g. priority and automatic parens handling.
A generic AST rewriting that disambiguates variables (very simple to write with
bindlib) is also added and used in the OCaml backend for something safer than
just appending `_user` (-- this also handles clashing variables that could be
introduced during compilation which would have generated wrong code before this)
Finally, the `explain` plugin is adapted to use the new printer.
Ah, and `String.format_t` was tweaked to correctly print strings that might
contain unicode without breaking alignment, and should be used instead of
`format_string` or `%s` whenever unicode can be expected.
- Use separate functions for successive passes in module `Driver.Passes`
- Use other functions for end results printing in module `Driver.Commands`
As a consequence, it is much more flexible to use by plugins or libs and we no
longer need the complex polymorphic variant parameter.
This patch leverages previous changes to use Cmdliner subcommands and
effectively specialises the flags of each Catala subcommand.
Other changes include:
- an attempt to normalise the generic options and reduce the number of global
references. Some are ok, like `debug` ; some would better be further cleaned up,
e.g. the ones used by Proof backend were moved to a `Proof.globals` module and
need discussion. The printer no longer relies on the global languages and prints
money amounts in an agnostic way.
- the plugin directory is automatically guessed and loaded even in dev setups.
Plugins are shown by the main `catala` command and listed in `catala --help`
- exception catching at the toplevel has been refactored a bit as well; return
codes are normalised to follow the manpage and avoid codes >= 128 that are
generally reserved for shells.
Update tests
(first working dynload test with compilation done by manual calls to ocaml)
A few pieces of the puzzle:
* Loading of interfaces only from Catala files
* Registration of toplevel values in modules compiled to OCaml, to allow access
using dynlink
* Shady conversion from OCaml runtime values to/from Catala expressions, to
allow interop (ffi) of compiled modules and the interpreter
