fdd5aec172
This refactors and improves the `#eval` command, introducing some new
features.
* Now evaluated results can be represented using `ToExpr` and pretty
printing. This means **hoverable output**. If `ToExpr` fails, it then
tries `Repr` and then `ToString`. The `eval.pp` option controls whether
or not to try `ToExpr`.
* There is now **auto-derivation** of `Repr` instances, enabled with the
`pp.derive.repr` option (default to **true**). For example:
```lean
inductive Baz
| a | b
#eval Baz.a
-- Baz.a
```
It simply does `deriving instance Repr for Baz` when there's no way to
represent `Baz`. If core Lean gets `ToExpr` derive handlers, they could
be used here as well.
* The option `eval.type` controls whether or not to include the type in
the output. For now the default is false.
* Now things like `#eval do return 2` work. It tries using
`CommandElabM`, `TermElabM`, or `IO` when the monad is unknown.
* Now there is no longer `Lean.Eval` or `Lean.MetaEval`. These each used
to be responsible for both adapting monads and printing results. The
concerns have been split into two. (1) The `MonadEval` class is
responsible for adapting monads for evaluation (it is similar to
`MonadLift`, but instances are allowed to use default data when
initializing state) and (2) finding a way to represent results is
handled separately.
* Error messages about failed instance synthesis are now more precise.
Once it detects that a `MonadEval` class applies, then the error message
will be specific about missing `ToExpr`/`Repr`/`ToString` instances.
* Fixes a bug where `Repr`/`ToString` instances can't be found by
unfolding types "under the monad". For example, this works now:
```lean
def Foo := List Nat
def Foo.mk (l : List Nat) : Foo := l
#eval show Lean.CoreM Foo from do return Foo.mk [1,2,3]
```
* Elaboration errors now abort evaluation. This eliminates some
not-so-relevant error messages.
* Now evaluating a value of type `m Unit` never prints a blank message.
* Fixes bugs where evaluating `MetaM` and `CoreM` wouldn't collect log
messages.
The `run_cmd`, `run_elab`, and `run_meta` commands are now frontends for
`#eval`.
26 lines
734 B
Text
26 lines
734 B
Text
import Lean.CoreM
|
|
|
|
/-!
|
|
Check that C++ exceptions are properly translated to Lean data.
|
|
In particular, runtime exceptions such as `interrupted_exception` should properly transition from
|
|
`libInit_shared` to `libleanshared`, which requires correct linking of the unwinding library.
|
|
-/
|
|
|
|
open Lean
|
|
#guard_msgs in
|
|
#eval show CoreM _ from do
|
|
let env ← getEnv
|
|
let envPromise ← IO.Promise.new
|
|
let tk ← IO.CancelToken.new
|
|
let t := Task.spawn fun _ =>
|
|
let env := envPromise.result.get
|
|
let decl := .axiomDecl {
|
|
name := `test
|
|
levelParams := []
|
|
type := mkConst `Nat
|
|
isUnsafe := false
|
|
}
|
|
env.addDeclCore 1000 decl tk
|
|
tk.set
|
|
envPromise.resolve env
|
|
assert! t.get matches .error .interrupted
|