When enabled, we handle protected imports as if the semantic cache was
empty:
* Protected imports are resolved again, downloaded or read from
the filesystem as necessary.
* Protected imports are β-normalized, not αβ-normalized.
* Protected imports are checked against their SHA256 hashes,
failing to resolve if they don't match.
Context:
https://github.com/dhall-lang/dhall-haskell/pull/1275#issuecomment-528847192
* Add a haddock to explain the various `Binding` fields.
* Add combinators to make dealing with `Binding` less awkward.
With all of the source information flying around, manually
deconstructing and reconstructing `Binding`s is a pain. These
combinators cover some very common cases.
* Use `bindingExprs` to simplify `subExpressions`.
* Use bindingExprs and chunkExprs to simplify another traversal.
Closes#1185.
This mostly reverts "Add support for multi-`let` (#675)" /
8a5bfaa3b9.
Also:
* Add fields for Src
This is useful for to make 'Note's less noisy during debugging:
first srcText expr
* 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
* 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 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`
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.
* 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
Part of https://github.com/dhall-lang/dhall-lang/issues/563
This flag freezes imports in the same way as the Prelude by providing a
fallback unprotected import without an integrity check. The primary use
case for this is caching imports with a graceful fallback, which is why
the flag is named `--cache`
This adds a new `Dhall.Test.Util.discover` utility for auto-generating
a `TestTree` from a directory tree. This simplifies keeping up to date
with changes to the standard test suite.
- Dhall.Eval: new evaluator, conversion checker and normalizer.
There is no standalone alpha normalizer yet.
- There is a new option "new-normalize" for dhall executable, which uses
the new normalizer.
- Type checker is unchanged.
- new implementation: alphaNormalize, judgmentallyEqual, normalize
- normalizeWith takes a Maybe ReifiedNormalizer argument now, and switches to
the new evaluator whenever the input normalizer is Nothing
- QuickCheck test for isNormalized removed, because we don't support evaluation
of ill-typed terms, which the test would require.
... as standardized in https://github.com/dhall-lang/dhall-lang/pull/426
This adds two new `ToTerm`/`FromTerm` classes in order to minimize
code disruption. The main disruption is due to renaming the old
`encode`/`decode` to `encodeExpression`/`decodeExpression`
... as standardized in https://github.com/dhall-lang/dhall-lang/pull/438
This also adds `dhall-json` support for empty alternatives
In particular, this translates empty alternatives to strings encoding the alternative name
```haskell
-- ./example.dhall
let Role = < Wizard | Fighter | Rogue >
in [ Role.Wizard, Role.Fighter ]
```
```
$ dhall-to-json <<< './example.dhall'
["Wizard","Fighter"]
```
.. as caught by @Profpatsch in:
https://github.com/dhall-lang/dhall-haskell/pull/812#issuecomment-462134701
Before this change the location was always being reported as `(stdin):1:1`
because the `SourcedException` kept getting modified with a broader
source location in the `Note` branch of `loadWith`.
This was originally done so that alternative imports would show the entire
source span, but it mistakenly just kept bubbling up regardless of whether or
not there were alternative imports.
Instead, this includes an approximate source span for alternative imports.
The source span bounds are correct but the contents just show which imports
were alternated, even if they might have been buried in a larger expression.
For example, if the original expression had been:
```haskell
Some ./x ? None ./y
```
... then the source span for the error message would display just:
```haskell
./x ? ./y
```
... which is probably as good as it will get for now.
This is essentially a revert of 25d86e8e5d
The primary motivation for this is so that paths beginning with `../`
don't get reformatted to begin `./../`.
The secondary motivation for this is to more closely match the standard.
There are fewer special cases in the logic if there is a dedicated
constructor for the `Parent` case.
* Add dotgen as a dependency
Signed-off-by: Basile Henry <bjm.henry@gmail.com>
* Build up dot graph while resolving imports
Signed-off-by: Basile Henry <bjm.henry@gmail.com>
* Add --dot option to resolve in CLI
Signed-off-by: Basile Henry <bjm.henry@gmail.com>
* Handle diamond dependencies in dot graph
* Refactor dot graph generation
This fixes an apparently very old bug in import caching caught by @basile-henry
Before this change the import resolution algorithm was:
1. Retrieving the cache
2. Transitively resolving all imports
3. Setting the new cache to be current import insert into the cache retrieved in
step 1
The bug is that all of the transitive imports resolved in step 2 added
entries of their own to the cache and those new cache entries were being
clobbered by step 3.
The fix is simple: don't use the cache retrieved in step 1 to compute
the updated cache in step 3. Rather, use `modify` instead of `put` to
create the new cache so that we preserve newly-added cache entries.
Javier Neira
Simon Jakobi
Patrick Mylund Nielsen
quasicomputational
Gabriel Gonzalez
Ollie Charles
Frederik Ramcke
Mario
Fabrizio Ferrai
AndrasKovacs
Basile Henry