d4dca3baac
This adds a `test_extern` command. Usage: ``` import Lean.Util.TestExtern test_extern Nat.add 17 37 ``` This: * Checks that the head symbol has an `@[extern]` attribute. * Writes down `t == t'`, where `t` is the term provided, and `t'` is the reference implementation (specifically, `t` with the head symbol unfolded). * Tries to reduce this to `true`, and complains if this fails. Note that the type of the term must have a `BEq` instance for this to work: there's a self-explanatory error message if it isn't available.
3 lines
97 B
Text
3 lines
97 B
Text
@[extern "lean_nat_add"]
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protected def Nat.not_add : (@& Nat) → (@& Nat) → Nat
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| _, _ => 0
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