Since they'll be incompatible between different Idris2 versions, this
helps protect against importing the wrong thing by mistake. Also, it
means the canonical place for the version number is now the top level
Makefile.
You'll need to delete src/YafflePaths.idr before rebuilding, since it's
now generated slightly differently.
This is so that we can put other build artefacts (e.g. executables) in
properly organised subdirectories of build, e.g. build/bin/chez,
build/bin/js, etc.
In the Chez back end, if the library spec is a name and a version
number, build an appropriate guess for the library file name based on
the system extension.
Functions can be declared as %foreign with a list of calling
conventions, which a backend will work through until it finds one it can
understand. Currently implemented only in Chez backend. If this works
out, I'll implement it for Racket too, and remove the old primitive
functions.
There's a bit more boiler plate here than before, but it has the benefit
of being more extensible and portable between different back ends.
Some examples, pending proper documentation:
%foreign "C:puts,libc" "scheme:display"
putline : String -> PrimIO ()
%foreign "C:exp, libm.so.6, math.h"
fexp : Double -> Double
%foreign "C:initscr, ncurses_glue.so, ncurses.h"
prim_initscr : PrimIO ()
On NixOS, idris2 can't find scheme in the usual locations, so it
defaults to generating the following shebang:
#!/usr/bin/env scheme --script
The `env` program interprets `scheme --script` as one monolithic
command, instead of as a command and one argument.
/usr/bin/env: ‘scheme --script’: No such file or directory
/usr/bin/env: use -[v]S to pass options in shebang lines
The -S flag forces `env` to split on whitespace in the intuitive
manner.
Fixes#92, because it wasn't re-evaluating the type and establishing
that the thing it was looking for must be a Fin for fromInteger so
resorting to the default integer literal instead.
Sometimes we swap the arguments, to reduce code duplication, but we need
to remember we've done that since (1 x : a) -> b is valid for an
argument of type (x : a) -> b, but not vice versa (that is, we have a
teensy bit of subtying to deal with, for convenience...).
This fix seems a bit ugly, but we do at least now propagate the
information. Fixes#82.
This ignores empty lines in the REPL and doesn't show a parse error on
CTRL+D/EOF anymore.
Add NOP variant to REPLCmd to represent an empty command.
Split command in eoi or nonEmptyCommand. nonEmptyCommand is still
guaranteed to consume input. command may be eoi in which case it does
not consume input.
Print a newline after receiving EOF on the console. Since this is only
relevant in the REPL (quiet or not) this uses putStrLn rather than
iputStrLn.
I don't know why I originally made it 'Inf' only in the evaluator... but
we certainly want 'Lazy' delays to block too, especially if they're
guarding non-terminating computations.
This is supported by Idris 1 and is handy for breaking cycles in
modules. To achieve this, we just need to make sure that complete
definitions aren't overwritten with empty definitions on loading.
Checking the let expression in full can break sharing when unifying the
types, and it's unnecessary because we've already checked the type of
the scope unifies with the expected type.
Fixes#63
Elaborate the scope of a let without the computational behaviour,
meaning that `let x = v in e` is equivalent to `(\x => e) v`. This makes
things more consistent (in that let bindings already don't propagate
inside case or with blocks) at the cost of not being able to rely on the
computational behaviour in types. More importantly, it removes a
significant potential source of slowness.
Fixes#58
If you need the computational behaviour, you can use a local function
definition instead.
This is for finding support libraries for code generators, e.g. the
shared objects that chez will load for glue code for foreign libraries.
It'll be used more shortly...
Fixes#42. If we don't do this, the name is treated in the saem way as
an unbound implicit, which is not what we want, so update with the
method applied to the parameters.
We were only doing implicits, so add auto implicits too. It's slightly
tricky, because we might also have implicits given of the form @{x}
which stands for the next auto implicit.
Fixes#50
Just like all other pi-bound things, if m is an unbound implicit and we
have m ?x = m y as a unification problem, we can conclude ?x = y because
it has to be true for all ms.
This was implemented in Blodwen but I hadn't got around to it yet for
Idris2... fortunately it's a bit easier in Idris2!
Fixes#44
This will be useful shortly, and in general because it'll give us more
flexibility in unification to be able to spot things which are
guaranteed invertible like constructors.
We were only checking parameters, meaning that there were potential
clashes leading to confusing behaviour, and meaning that it was somehow
relevant what the names were in the interface!
Now by marking a method as multiplicity 0, we can explicitly say that
it's compile time only, so we can use it to compute types based on other
erased things - see tests/idris2/interface008 for a small example.
This fixes#8 - at least in that it allows the interface to be expressed
properly now, although the multiplicity annotations mean that
unfortunately it can't be compatible with Idris 1.
A local variable can't be applied to itself when searching (otherwise,
for example, we could end up trying something like id id id id id id etc
forever). So remove it from the environment before searching for its
arguments.
This and the previous patch fix#24. (Or, at least, the minimised cases
reported as part of it!)
Don't use the interface itself when checking parent implementations
exist, otherwise we'll end up in a cycle (because the parent
implementation will sort of exist as a result!)
We can't begin a search until we know what we're searching for! For some
reason I forgot to add this case, and without it the search space can
explode, or we might find an answer too soon and commit to the wrong
thing!
Fixes#36
This means that even if the relevant parameters aren't used by a method
body, the method can still see what the implicits are (though they will
be 0 multiplicity).
This is relevant to #8, but doesn't really fix it because we still need
a way of saying that methods are 0 multiplicity.
We need to turn pairs into separate constraints, which is a bit of a
hack but the constraints need to be separate in order to build the
chasing functions which find the parent constraints correctly.
Possibly there is a neater way, which is to teach the search algorithm
to look in the hints for pairs, but that's a lot more complicated (and
probably unnecessarily so).
Fixes#25
This is a bit rough, but does yield an executable with a ~40% speedup in
startup latency on one test. The resulting executable is a .so file with a #!
invocation of the local chez scheme executable to run it, so the binary isn't
portable (even to a machine with the same architecture/OS) unless there's an
identical chez installation on both machines.
As with the .ss source, the .so is currently leaked in the temporary directory.
They're just about deciding whether it's okay to start an auto implicit
search, not whether it's okay to continue search, which is part of the
problem in #25.
This hasn't been tested much (and indeed isn't in the test suite because
I haven't found the way to load shared objects nicely portably yet!) so
I hadn't noticed, but primitive types are translated to names before
compilation to support matching on types, so we need to account for
this.
Also, CG directives need to be processed after loading from ttc
We can't nest delayed elaborators (this is an efficiency constraint, to
prevent excessive searching for ambiguous names) to run elaborator
immediately if delays aren't allowed in delayElab
This is part of what we used to have in Enum but I think it's better to
separate the two. Added implementations for Nat, and anything in
Integral/Ord/Neg, so that we get range syntax (at least when its
implemeted) for the most useful cases.
This required a small change to auto implicit search (and I'm still not
sure about this). Now search arguments right to left, because solving
later arguments may resolve earlier arguments by unification and this
can happen in particular when chasing parent interfaces (which may have
fewer parameters).
Take the earliest failure message, since they'll typically be more
precise (later search groups being for chasing parent interfaces and
defaults). This is mostly as a heuristic to help show whether one part
of a pair failed in implicit search.
At least on Linux, \r needs to be in singles quotes as an argument to tr
or it removes all the 'r' instead! Hopefully it also works this way on
Windows...
These are 'nested' namespaces which are a bit special in that even
private names are visible from the enclosing namespace. This gets the
behaviour for record visibility from Idris 1.
Need to set up nested names appropriately for the with function so that
the environment gets passed through correctly, and use abstractEnvType
to get the type of the with function rather than simply binding the
environment as is.
Now supports with applications on the RHS when auto implicits are
involved. Auto implicit bound names in patterns now become searches on
the rhs in a with-application (I should write this construct up properly
in a paper some time!)
We don't use level, so remove it. Added a field bindingVars which
records whether implicit names should be bound if unsolved. This needs
to be separate from the elaboration mode because we might encounter new
holes inside dot patterns which are matched elsewhere.
We use this to decide whether a determining argument is satisfied or not
for unbound implicits. We can tell from the name, which would be a PV,
but this way relies on fewer assumptions.
Elaborate via either === (homogeneous equality) or ~=~ (heterogeneous
equality) both of which are synonyms for Equal. This is to get the Idris
1 behaviour that equality is homogeneous by default to reduce the need
for type annotations, but heterogeneous if that doesn't work.
There's a bit of a trade off here. It would be better to report the
ambiguity but this would lead to a need for (I think) excessive
precision in types which would impact usability. It will always take the
leftmost interface.
Chapter 7 tests added.
Idris 1 will fill in the last metavariables by matching rather than
unification, as a convenience. I still think this is okay, even if it's
a bit hacky, because it's a huge convenience and doesn't affect other
unification problems.
Also abstract over lets in guesses, like in delayed elaborators, to
avoid any difficulties when linearity checking and to make sure that let
bound things don't get reevaluated.
This is enough to get the Chapter 6 TypeDD tests working
Allow matching rather than unification, as long as it doesn't solve any
metavariables on the way. I noticed a potential unification bug on the
way, forgetting to update whether holes are solved when unifying
argument lists.
This was left over from Blodwen (where it was also wrong :)) but the way
we apply metavariables now means we don't need to do anything fancy when
unelaborating them for pretty printing.
Like in delayed ambiguity resolution, we need to reevaluate the target
type because it might have changed - and that's why we delayed in the
first place!
Where "simple" means the solution is just a local variable or smaller
metavariable application. This is a big win when environments get big,
and I suspect there might be more where this came from if we always
shrink the environments of metavariable solutions as far as possible. It
really saves a lot of work in "quote" in particular.
Surprisingly == on Nat in the Idris prelude is linear! So shortcut that
by converting to an Integer first. Also a couple of small things in the
evaluator that have a small but noticeable effect when environments are
big.
This has shown up a problem with 'case' which is hard to fix - since it
works by generating a function with the appropriate type, it's hard to
ensure that let bindings computational behaviour is propagated while
maintaining appropriate dependencies between arguments and keeping the
let so that it only evaluates once. So, I've disabled the computational
behaviour of 'let' inside case blocks. I hope this isn't a big
inconvenience (there are workarounds if it's ever needed, anyway).
Need to add by full name, due to ordering of loading (the name it's
attached to may not be resolved yet!). This doesn't seem to cause any
performance problems but we can revisit if it does.
Don't use the type of a scrutinee to restrict possible patterns, because
it might have been refined by a Rig0 argument that has a missing case.
Instead, generate all the possible cases and check that the generated
ones are impossible (there's no obvious change in performance)
Small change needed to fix one - assume given implicits which are of the
form x@_ arise from types. It's a bit of a hack but I don't think
there's any need for anything more complicated.
Only valid if unifying the pattern at the end doesn't solve any
metavariables. Also when elaborating applications of fromInteger etc to
constants on the LHS we need to be in expression mode, then reduce the
result later.
This was a slight difference from Blodwen that wasn't accounted for -
there might be lets in the nested environment, so when building the
expanded application type, make sure we go under them
This wasn't necessary before, since we always inlined, but since we can
now postpone things longer and don't always inline until much later, we
need to know what names everything refers to earlier.
Since lookup up a binding can be expensive in a big environment, and we
only need to reduce it if it turns out to be a let, caching it can be a
noticeable win
We can't refine by a name in Rig0 because we can't assume it covers all
possibilities, so only refine by them at the end, at which point we
check that there's only one case left (otherwise we have to match on it,
which is not allowed for an erased thing)
Then on reloading, only decode the Binary when it's first looked up.
This is a huge win on loading because it's decoding the binary blob that
costs, rather than loading it!
Also fix a bug where the elaborator state wasn't updated on completing
the delayed elaborator, which could cause issues with implicitly bound
names in particular.
Need to run delayed elaborators before binding implicits, since there
might be some inside the delayed elaborator. Also reorganise TTC
implementations so they're all in one place.
Needs to be allowed to search for things indexed by pattern variables,
which are not really holes in the same sense, or it might not find
things in types.
(Aside: we're currently implicitly binding failed searches in types,
which is, I think, wrong... better to report the failure)
Don't build these until we've completed the whole clause (that is, don't
do it if we're inside a case block) because we might need to collect
more information to complete checking the case block. e.g. there may be
constraints inside the case block that are resolved outside.
It's just in the way, we don't use it for anything, and everything we
might get out of it we're already getting out of the type. Revisit later
if it turns out to be worth it.
If we store them on the type constructor, we're required to have the
construction available, which might not be the case when reloading ttcs,
because we load and process modules *before* things they import.
With the --yaffle flag, you get the old behaviour which is to invoke the
checker for the core theory (and all the tests are updated appropriately
for this).
This gives useful information for expression search, because we can add
lambdas while we're still building the environment, and start looking at
locals after that.
It turns out we need a new kind of map, mapping possibly ambiguous names
to values. This is what 'Context' does but we can only have one of them
because it resolves names to a position in an array and it'd be
confusing to have more than one index per name.
Mostly direct from Blodwen (some minor modifications to deal with new
way of going into a new scope in the elaborator as well as the usual
bits dealing with name lookup and Glued terms)
And process them on loading. We record that hints need saving out when
adding them, and clear that list unless we happen to be reexporting the
thing we've just read (import public).
Like Idris 1, these are implicitly added on encountering a repeated name
or a non-constructor application. Unlike Idris 1 (and Blodwen) they are
checking by unification rather than matching (which means in particular
that function argument names can't be bound in dot patterns) which is
slightly less expressive, but better overall because matching is
potentially more error prone.
Slight change of plan: instead of having special names, add Lazy, Inf,
Delay and Force and keywords and elaborate them specially.
Correspondingly, add DelayCase for case trees. Given that implicit
laziness is important, it seems better to do it this way than constantly
check whether the name we're working with is important.
This turns out to make implicit laziness much easier, because the
unifier can flag whether it had to go under a 'Delayed' to succeed, and
report that back to the elaborator which can then insert the necessary
coercion.
This shortcuts ambiguity checking by only keeping the things which have
the target type. Given a set of ambiguous applications, the rules are:
- keep any which return the expected target type (a concrete match), or
a polymorphic type (a possible match)
- if there are any concrete matches, drop any possible match which has
the '%allow_overloads' flag set (in practice this will be interface
methods, but other things can be flagged).
- if there ar eno matches, keep everything so that the error messages
show everything that went wrong.
Most notably, when elaborating deferring argument, if the hole
standing for the argument is still a hole, fill it in directly rather
than going via unification. This prevents some needless evaluation.
This slows things down a bit because to find the holes and give them the
right multiplicities, we need to normalise all the arguments which might
have been metavariables. Maybe we should skip this if we're not using
anything linear, for efficiency?
As patterns are handled by deciding which side of the as is considered
'used'. In case blocks, that should be the variable name, but in general
it should be the pattern, so IAs now has a flag to say which one.
Need to record which holes are still to be solved (not counting
elaborations where there are user defined holes) and check at the end
that they are now solved.
