Previously we had some heuristics in the backends trying to achieve this with a
lot of holes ; this should be much more solid, relying on `Bindlib` to do the
correct renamings.
**Note1**: it's not plugged into the backends other than OCaml at the moment.
**Note2**: the related, obsolete heuristics haven't been cleaned out yet
**Note3**: we conservatively suppose a single namespace at the moment. This is
required for e.g. Python, but it forces vars named like struct fields to be
renamed, which is more verbose in e.g. OCaml. The renaming engine could be
improved to support different namespaces, with a way to select how to route the
different kinds of identifiers into them.
Similarly, customisation for what needs to be uppercase or lowercase is not
available yet.
**Note4**: besides excluding keywords, we should also be careful to exclude (or
namespace):
- the idents used in the runtime (e.g. `o_add_int_int`)
- the dynamically generated idents (e.g. `embed_*`)
**Note5**: module names themselves aren't handled yet. The reason is that they
must be discoverable by the user, and even need to match the filenames, etc. In
other words, imagine that `Mod` is a keyword in the target language. You can't
rename a module called `Mod` to `Mod1` without knowing the whole module context,
because that would destroy the mapping for a module already called `Mod1`.
A reliable solution would be to translate all module names to e.g.
`CatalaModule_*`, which we can assume will never conflict with any built-in, and
forbid idents starting with that prefix. We may also want to restrict their
names to ASCII ? Currently we use a projection, but what if I have two modules
called `Là` and `La` ?
- 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
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.
- 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
The module is renamed to `Mark`, and functions renamed to avoid redundancy:
`Marked.mark` is now `Mark.add`
`Marked.unmark` is now `Mark.remove`
`Marked.map_under_mark` is now simply `Mark.map`
etc.
`Marked.same_mark_as` is replaced by `Mark.copy`, but with the arguments
swapped (which seemed more convenient throughout)
Since a type `Mark.t` would indicate a mark, and to avoid confusion, the type
`Marked.t` is renamed to `Mark.ed` as a shorthand for `Mark.marked` ; this part
can easily be removed if that's too much quirkiness.
- Fix the printer for scopes
- Improve the printer for struct types
- Remove `Print.expr'`. Use `Expr.format` as the function with simplified arguments instead.
- `Print.expr` no longer needs the context
- This removes the need for `expr ~debug` + `expr_debug` ;
use `Print.expr` for normal (non-debug) output,
and `Print.expr' ?debug ()` for possibly debug output.
- This improves consistency of debug expr output in many places
- Prints simplified operators (without type suffix) in non-verbose mode
(this patch also fixes some cases of `Expr.skip_wrappers` and leverages the
binder equality provided by Bindlib)
This uses the same disambiguation mechanism put in place for
structures, calling the typer on individual rules on the desugared AST
to propagate types, in order to resolve ambiguous operators like `+`
to their strongly typed counterparts (`+!`, `+.`, `+$`, `+@`, `+$`) in
the translation to scopelang.
The patch includes some normalisation of the definition of all the
operators, and classifies them based on their typing policy instead of
their arity. It also adds a little more flexibility:
- a couple new operators, like `-` on date and duration
- optional type annotation on some aggregation constructions
The `Shared_ast` lib is also lightly restructured, with the `Expr`
module split into `Type`, `Operator` and `Expr`.
Many changes got bundled in here and would be too tedious to separate.
Closes#330
See changes in `shared_ast/definitions.ml` to check the main point.
- the biggest change is a modification of the struct and enum types in
expressions: they are now stored as `Map`s throughout passes, and no longer
converted to indexed lists after scopelang. Their accessors are also changed,
and tuples only exist in Lcalc (they're used for closure conversion).
This implied adding some more information in the contexts, to keep the mapping
between struct fields and scope output variables. It should also be much more
robust (no longer relying on assumptions upon different orderings).
- another very pervasive change is more cosmetic: the rewrite of the main AST to
use inline records, labelling individual subfields.
- moved the checks for correct definitions and accesses of structures from
`Scope_to_dcalc` to `Typing`
- defining some new shallow iterators in module `Shared_ast.Expr`, and
factorising a few same-pass rewriting functions accordingly (closure
conversion, optimisations, etc.)
- some smaller style improvements (ensuring we use the proper compare/equal
functions instead of `=` in a few `when` closes, for example)
This was the only reasonable solution I found to the issue raised
[here](https://github.com/CatalaLang/catala/pull/334#discussion_r987175884).
This was a pretty tedious rewrite, but it should now ensure we are doing things
correctly. As a bonus, the "smart" expression constructors are now used
everywhere to build expressions (so another refactoring like this one should be
much easier) and this makes the code overall feel more
straightforward (`Bindlib.box_apply` or `let+` no longer need to be visible!)
---
Basically, we were using values of type `gexpr box = naked_gexpr marked box`
throughout when (re-)building expressions. This was done 99% of the time by
using `Bindlib.box_apply add_mark naked_e` right after building `naked_e`. In
lots of places, we needed to recover the annotation of this expression later on,
typically to build its parent term (to inherit the position, or build the type).
Since it wasn't always possible to wrap these uses within `box_apply` (esp. as
bindlib boxes aren't a monad), here and there we had to call `Bindlib.unbox`,
just to recover the position or type. This had the very unpleasant effect of
forcing the resolution of the whole box (including applying any stored closures)
to reach the top-level annotation which isn't even dependant on specific
variable bindings. Then, generally, throwing away the result.
Therefore, the change proposed here transforms
- `naked_gexpr marked Bindlib.box` into
- `naked_gexpr Bindlib.box marked` (aliased to `boxed_gexpr` or `gexpr boxed` for
convenience)
This means only
1. not fitting the mark into the box right away when building, and
2. accessing the top-level mark directly without unboxing
The functions for building terms from module `Shared_ast.Expr` could be changed
easily. But then they needed to be consistently used throughout, without
manually building terms through `Bindlib.apply_box` -- which covers most of the
changes in this patch.
`Expr.Box.inj` is provided to swap back to a box, before binding for example.
Additionally, this gives a 40% speedup on `make -C examples pass_all_tests`,
which hints at the amount of unnecessary work we were doing --'
Note that there were significant differences between the two printers (see the test diff!). Overall the `dcalc` one seemed newer so that's what I took, with only the required additions from `lcalc` (exceptions, raise and catch)
Handling code should now be reasonably well sorted between `Shared_ast.{Var,Expr,Scope,Program}`
The function parameters (e.g. `make_let_in`) could be removed from the
scope handling functions since now the types are compatible, which
makes them much easier to read.
