* Remove Dhall.X and replace with Data.Void
This commit removes the Dhall.X module and the Dhall.X.X type,
preferring the use of Data.Void.Void. As I'm sure a lot of people are
actually using X, I've added a type-alias type X = Void. However,
pattern matching on X would be a breaking change.
Fixes#1120.
* Restore unsafeCoerce
* Fix regression
* Unused
* Reorganise exports
* Fix dhall-nix
* Another fix
* Fix Dhall.LSP.Backend.Typing
* Fix dhall-bash
…to fix build failures due to the submodule pointing at an unreachable commit.
* Disable a currently failing testcase.
* Update the extra-source-files in dhall.cabal.
Several failed remote import messages didn't include the URL that
the interpreter failed to resolve. This change fixes that and includes
some slight tweaks to improve consistency in how the messages are
formatted.
* Remove most uses of `StandardVersion` from the API
We no longer support multiple versions of the standard, except for
supporting old integrity checks, so this change removes all inessential
uses of `StandardVersion` from the API and command-line interface.
* Fix `dhall-lsp-server` build
The motivation for this is two-fold:
* To get rid of the standard version from the output
Currently it's just "None", which could be fixed, but keeping it up to
date is error-prone, so I prefer to just remove it.
* To make the output machine-readable
Example:
```
$ dhall version
1.24.0
```
The motivation for this change is to avoid α-normalizing all imported
expressions.
For example, before this change you would get the following behavior
beginning with an empty cache
```
$ cat ./example.dhall
λ(a : Type) → a
$ dhall <<< './example.dhall'
λ(_ : Type) → _
```
The reason why is that the current code α-normalizes all imported
expressions, even when returning them fresh.
To fix this, I changed the `ImportSemantics` type to not require that
expressions are α-normalized. Instead, the α-normalization only
happens at the last minute when interacting with the semantic cache, but
nowhere else.
I figured that this change would also be fine from the perspective of
the semi-semantic cache because false-negatives for this cache are
fine. In particular, we probably don't mind if we get a cache miss for
the semi-semantic cache if the user renames a variable.
After this change imports are no longer α-normalized, whether loaded
from a hot or cold cache:
```
$ cat ./example.dhall
λ(a : Type) → a
$ dhall <<< './example.dhall'
λ(a : Type) → a
$ dhall <<< './example.dhall'
λ(a : Type) → a
```
* Allow customization of remote import resolution
Makes the `Status` type more general; previously support for
`Network.HTTP.Client` was hardcoded. In short:
```
data Status = Status
{ _stack :: NonEmpty Chained
[...]
-- , _manager :: Maybe Dynamic
-- -- importing the same expression twice with different values
++ , _remote :: URL -> StateT Status IO Data.Text.Text
++ -- ^ The remote resolver, fetches the content at the given URL.
[...]
}
```
* Simplify and expose `toHeaders`
`toHeaders` will be needed for mock http testing
* Fix compilation without `with-http` flag
* Fix compilation with `with-http` flag
* Fix tests without `with-http` flag
Implements a mock http client that handles requests to:
- `https://raw.githubusercontent.com/dhall-lang/dhall-lang/master/`
- `https://test.dhall-lang.org/Bool/package.dhall`
- `https://httpbin.org/user-agent`
This allows tests involving remote imports to succeed even when compiled
without the `with-http` flag.
* Build `dhall` with HTTP support compiled out in CI
... to prevent regressions from occurring in the future
* Tag ImportSemantics with their semantic hashes
This is in preparation for semi-semantic caching.
* Collect the list of imports during import resolution
The final step needed in preparation for semi-semantic caching!
* Implement semi-semantic caching
This completes the implementation of the "semi-semantic caching"
proposal (issue #1098).
We compute the semi-semantic hash of a dhall import/file/expression as
follows:
- Parse the input;
- compute the semantic hashes of all imports referenced in the AST, i.e.
the hashes of their normal forms;
- compute the syntactic hash of the input (hashing the parsed AST);
- concatenate the syntactic hash of the input with the semantic hashes
of its imports and hash the result.
The "semi-semantic" cache (normal forms, indexed by semi-semantic
hashes) has the following properties:
- For a given input we can quickly find out if it is in the cache: we
only need to parse the input – we don't need to typecheck or normalise
it!
- The cache stays consistent, that is, we don't need to ‘invalidate’ old
cache entries if their dependencies change!
* Simplify semi-semantic hash
As suggested by @Gabriel439.
* Simplify code
We don't actually need to carry the list of imports around when loading.
* Restore `load`
* Fix `isNormalized` test
The test in question failed intermittently because `isNormalized` is
more thorough than `normalize`, in the sense that it throws exceptions
for more non-welltyped expressions. As a result, we need to use `spoon`
not just when computing the normal form of a raw expression, but also
when calling `isNormalized` on the result. Note that the test may still
randomly fail in the future, because normalizing non-welltyped
expressions needn't terminate!
* Comment on non-totality of `isNormalized`
From dhall/tests/Dhall/Test/Regression.hs:
These two examples contain the following expression that loops
infinitely if you normalize the expression before type-checking the
expression:
(λ(x : A) → x x) (λ(x : A) → x x)
The problem is typechecking that snipped already fails even before we
hit the self-application with the following error:
Unbound variable: A
This is fixed by quantifying over `A`, resulting in the desired type
error:
Error: Not a function
1│ x x
Previously, `BAD="0 0" dhall <<< "env:BAD ? 0"` resulted in the
following error:
```
↳ env:BAD
Error: Not a function
1│ 0 0
BAD:1:1
```
According to the standard the above expression was supposed to evaluate
successfully to `0`. See #1146 for further discussion.
* Load imports recursively
This is the big change that enables us to implement 'semi-semantic'
caching.
* Use `throwM` instead of `liftIO . throwIO`
* Fix build with __GHCJS__
* Fix exceptions in Dhall.Import
* Fix dhall-lsp-server
* Revert exception behaviour on typecheck errors
This is one for a separate pull request!
* Make sure loadImportFresh returns alpha-normal expression
As caught by @Gabriel439, `loadImportFresh` violated the invariant that
`ImportSemantics` should be alpha-beta-normal. This fix also means that
we don't have to alpha-normalise again in `loadImportWithSemanticCache`.
* Remove old comment
* Fix regression test for issue 216
Turns out the test was testing the wrong thing, because it was
pretty-printing an import. This worked previously because when importing
uncached expressions we would not alpha-normalise them.
* Restore `dhall freeze` bevhaviour
Newly frozen imports should also be present in the cache.
* Forbid invalid codepoints
... as standardized in https://github.com/dhall-lang/dhall-lang/pull/640
* Don't validate code points outside of escape sequences
... as suggested by @sjakobi
It's not necessary (since the `text` package forbids invalid UTF8) and
slows down performance as verified by the `dhall-parser` comment parsing
benchmarks
* Restore `nonCharacter` parsing test
Previously, ill-typed expressions like this one got into normalization:
toMap {=} : <>.x
Also:
* Tweak Expr's Arbitrary instance:
- Boring nullary constructors don't need to be so frequent.
- Large NaturalLits can cause normalization to OOM, which we don't
want when running the testsuite.
* Add property test to check that all well-typed expressions can be
normalized.
* Implement dhall.freezeImport and dhall.freezeAllImports
* Remove old (broken) test suite
* Rename `relativePosition` to `subtractPosition`
as suggested by @Gabriel439
* Add doctest for `subtractPosition`
as suggested by @Gabriel439
* Simplify getImportHashPosition
As spotted by @Gabriel439
* Use `forM` instead of `mapM` for prettier code
As suggested by @Gabriel439
* Check normalizeWithM for consistency with normalize
* Implements constant folding of Natural/fold applications normalizeWithM.
* Changes the Arbitrary Var instance to generate only non-negative indices.
Otherwise failures like this one would pop up:
normalizeWithM should be consistent with normalize: FAIL (8.51s)
*** Failed! Falsified (after 318133 tests and 6 shrinks):
Let (Binding {variable = "", annotation = Nothing, value = List} :| []) (Var (V "" (-1)))
Var (V "" (-1)) /= Var (V "" (-2))
Use --quickcheck-replay=180244 to reproduce.
Fixes https://github.com/dhall-lang/dhall-haskell/issues/1114.
* QuickCheck tests: Specialize the 'natural' Gen to Naturals
Previously it could produce about any number, not just non-negative
ones.
To be more precise (citing the haddocks):
Given a well-typed expression e, (isNormalized e) is equivalent to
(e == normalize e).
Given an ill-typed expression, isNormalized may return True or False.
An even closer correspondence between isNormalized and 'normalize' is
currently tricky to achieve as 'normalize' returns errors only for some
ill-typed expressions. Once 'normalize' is more principled in this
regard, isNormalized could be changed to return a (Maybe Bool).
This re-enables a property test checking this consistency. Since
'normalize' returns errors for some ill-typed expressions, we
catch have to catch these, which requires an NFData for Expr.
* Fix misleading comment
* Add `Chained` type to capture fully chained imports
Until now we used `Import` two mean two different things:
- The syntactic construct; e.g. `./a.dhall` corresponds to the following
AST:
```
Embed
(Import
(ImportHashed Nothing (Local Here (Directory ["."]) "a.dhall"))
Code)
```
- The physical location the import is pointing to, computed by
'chaining' the syntactical import with the the 'physical' parent import.
For example the syntactic import `./a.dhall` might actually refer to the
remote file `http://host/directory/a.dhall`.
This commit adds a `Chained` newtype on top of `Import` to make this
distinction explicit at type level.
* Use `HTTPHeaders` alias for binary headers
I claim that `HTTPHeaders` is more readable and informative than the
unfolded type `(CI ByteString, ByteString)`.
* Typecheck and normalise http headers earlier
Previously we would typecheck and normalise http headers in
`exprFromImport`, i.e. while loading the import. This commit adds the
invariant that any headers in 'Chained' imports are already typechecked
and normalised, and moves this step into `loadWith` accordingly.
This causes a subtle difference in behaviour when importing remote files
with headers `as Location`: previously, nonsensical expressions like
`http://a using 0 0 as Location` were valid, while they would now cause
a type error.
* Fix dhall-lsp-server
* Fix Dhall.Import API regarding `Chained` imports
Do not expose the `Chained` constructor; we don't want external code
breaking our invariants! Also further clarifies the comment describing
the `Chained` type.
* Fix dhall-lsp-server
Since we are no longer able to construct `Chained` imports directly we
need to export a few additional helper functions from Dhall.Import.
Furthermore, since VSCode (and presumably the other editors out there
implementing the LSP protocol) does not support opening remote files
anyway we can get rid of some complications by dropping support for
remote files entirely on the back-end.
* Generalise decodeExpression, fixes TODO
* Fix tests
* Fix benchmarks
* Remove Travis cache for `~/.local/bin`
* Fix copy-pasted comment
Thanks to @Gabriel439 for spotting this!
* Add clarifying comment to `toHeaders`
It is not the case that
canonicalize (a <> b) = canonicalize a <> canonicalize b.
For example
canonicalize (Directory ["asd"] <> Directory [".."])
= Directory [],
but
canonicalize (Directory ["asd"]) <> canonicalize (Directory [".."])
= Directory ["..", "asd"].
The law we want instead is:
canonicalize (a <> b)
= canonicalize (canonicalize a <> canonicalize b)
* Expose `localToPath` in Dhall.Import
Also modifies `localToPath` to return a relative path if the input was
relative, rather than resolving relative paths by appending the current
directory.
* Turn imports into clickable links
This implements a handler for 'Document Link' requests. As a result,
imports are now clickable!
* Recover original behaviour
* Move "Dot" import graph generation to Dhall.Main
Previously `Dhall.Import` would generate the import graph in "dot"
format while resolving imports. This change simplifies `Dhall.Import` to
only keep track of the adjacency list representing the import graph,
moving the logic for generating "dot" files to Dhall.Main.
This change will allow us to implement proper cache invalidation for
`dhall-lsp-server`.
* Correctly invalidate transitive dependencies
Fixes dhall-lsp-server`s caching behaviour to correctly invalidate
cached imports that (possibly indirectly) depend on the changed file.
Example:
Suppose we have the following three files:
{- In A.dhall -} 2 : ./B.dhall
{- In B.dhall -} ./C.dhall
{- In C.dhall -} Natural
Previously, changing C.dhall to `Text` would not cause `A.dhall` to stop
type-checking, since the old version of `B.dhall` (which evaluated to
`Natural`) would still have been in the cache. This change fixes that
behaviour.
* Make edges of import graph self-documenting
As suggested by @Gabriel439
* Don't cache expressions manually
After computing the diagnostics for a given file we added its normal
form to the cache, but forgot to add its dependencies to the dependency
graph. This bug points out that keeping the import graph consistent
manually is probably not a good idea. With this commit we never mess
with the import cache manually; this means that files are only cached
once they are depended upon by some other file, potentially causing us
to duplicate work (but no more than once).
* Fix left-overs from previous commit
Fixes https://github.com/dhall-lang/dhall-haskell/issues/1082
All of the successes are due to accepting expressions that would not
have been produced by a compliant encoder, such as:
* Expressions that use a variable name of `_` that could have been
encoded more compactly
* An expression tagged as a `Natural` number storing a negative number
* An expression encoding a function appled to 0 arguments
