refactor: use a refinement type for Data.Vec#586
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4e554c4c wants to merge 28 commits intothe1lab:mainfrom
Open
refactor: use a refinement type for Data.Vec#5864e554c4c wants to merge 28 commits intothe1lab:mainfrom
4e554c4c wants to merge 28 commits intothe1lab:mainfrom
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| instance | ||
| Length-zero : Length {A = A} [] zero | ||
| Length-zero = zero | ||
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| Length-suc : ∀ {x n} {xs : List A} → ⦃ _ : Length xs n ⦄ | ||
| → Length (x ∷ xs) (suc n) | ||
| Length-suc ⦃ l ⦄ = suc l | ||
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| Length-length : ∀ {xs : List A} → Length xs (length xs) | ||
| Length-length {xs = []} = zero | ||
| Length-length {xs = x ∷ xs} = suc Length-length |
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Is there a point to having these as instances? Also, I think Length-length would have to be marked INCOHERENT...?
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i think i ran into this at some point yeahg
This makes a lot of inductive arguments easier
Now that lower < n is a definitional proposition, we don't need to worry about irrelevance here
This file typechecks, but I suspect that there is an Agda bug lurking
in the shaddows. If you try to typecheck Homotopy.Truncation, a call
to elim! throws the following error:
> Projection _≤_.is-leq is irrelevant.
> Turn on option --irrelevant-projections to use it (unsafe)
> when checking that the expression ._≤_.is-leq (Leq-refl {n}) has
> type Data.Bool.Base.is-true (suc (suc n) ≤? suc (suc n))
This seems to trigger when resolving the 'Inductive' instance using
Inductive-n-Tr, which has the type
> Inductive-n-Tr
> : ∀ {ℓ ℓ' ℓm} {A : Type ℓ} {n} {P : n-Tr A (suc n) → Type ℓ'} ⦃ i : Inductive (∀ x → P (inc x)) ℓm ⦄
> → ⦃ _ : ∀ {x} → H-Level (P x) (suc n) ⦄
> → Inductive (∀ x → P x) ℓm
Moreover, the problematic elim! is eliminating into the universe of
n-Types, which require us to use a hlevel-projection, so I think that
some sequence of events is causing the proof Leq-refl {n} to get
η-expanded to a (bogus) irrelevant projection, which then gets
re-checked by reflection, which then (rightfully) complains.
This seems to solve the issues with Homotopy.Truncation
Suggested-by: Amélia Liao <me@amelia.how>
resolves: the1lab#567 Co-authored-by: Reed Mullanix <reedmullanix@gmail.com>
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this is now rebased on #597 and doesn't chmod borceaux |
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resolves: #567
Description
As per a suggestion by @TOTBWF, this changes
Data.Vecto use a refinement type which codeslength xs = n.Unfortunately this means that induction on vecs now needs
vec-view, which makes some things messier. Worse still, I can't seem to use[]as a pattern for the empty vec since it conflicts with list, and use∷at all since it can't be a pattern.The order of instances is also changed a little bit, which means
[ p ]fails to realize as a list in1Lab.Reflection.List.I'd love some tips on how to make this a little bit cleaner :)
Checklist
Before submitting a merge request, please check the items below:
support/sort-imports.hs(ornix run --experimental-features nix-command -f . sort-imports).