statement
stringlengths
6
506
proof
stringlengths
0
2.66k
type
stringclasses
17 values
symbolic_name
stringlengths
1
55
library
stringclasses
5 values
filename
stringclasses
22 values
imports
listlengths
2
12
deps
listlengths
0
20
docstring
stringlengths
0
1.35k
source_url
stringclasses
1 value
commit
stringclasses
1 value
contract_equ `(c1 : contract i Ω1) `(c2 : contract i Ω2) : Type
:= | mk_contract_equ (f : Ω1 -> Ω2) (g : Ω2 -> Ω1) (iso1 : forall x, f (g x) = x) (iso2 : forall x, g (f x) = x) (caller_equ : contract_caller_equ c1 c2 f) (callee_equ : contract_callee_equ c1 c2 f) (witness_equ : contract_witness_equ c1 c2 f) : contract_equ c1 c2.
Inductive
contract_equ
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "contract", "contract_callee_equ", "contract_caller_equ", "contract_witness_equ" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
contract_iso_lr `(c1 : contract i Ω1) `(c2 : contract i Ω2) (equ : contract_equ c1 c2) (ω1 : Ω1) : Ω2
:= match equ with | @mk_contract_equ _ _ _ _ _ f _ _ _ _ _ _ => f ω1 end.
Definition
contract_iso_lr
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "contract", "contract_equ" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
contract_iso_rl `(c1 : contract i Ω1) `(c2 : contract i Ω2) (equ : contract_equ c1 c2) (ω2 : Ω2) : Ω1
:= match equ with | @mk_contract_equ _ _ _ _ _ _ g _ _ _ _ _ => g ω2 end.
Definition
contract_iso_rl
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "contract", "contract_equ" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
contract_equ_refl `(c : contract i Ω) : contract_equ c c.
Proof. apply mk_contract_equ with (f:=fun x => x) (g:=fun x => x); auto. + now intros ω α p. + now intros ω α p x. + now intros ω α p x. Defined.
Lemma
contract_equ_refl
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "contract", "contract_equ" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
contract_equ_sym `(c1 : contract i Ω1) `(c2 : contract i Ω2) (equ : contract_equ c1 c2) : contract_equ c2 c1.
Proof. induction equ. apply mk_contract_equ with (f0:=g) (g0:=f). + apply iso2. + apply iso1. + intros ω α p. transitivity (caller_obligation c2 (f (g ω)) p). ++ now rewrite iso1. ++ now symmetry. + intros ω α p x. transitivity (callee_obligation c2 (f (g ω)) p x). ++ now rewrite iso1. ...
Lemma
contract_equ_sym
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "contract", "contract_equ" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
contract_equ_trans `(c1 : contract i Ω1) `(c2 : contract i Ω2) `(c3 : contract i Ω3) `(is_equ12 : contract_equ c1 c2) `(is_equ23 : contract_equ c2 c3) : contract_equ c1 c3.
Proof. destruct is_equ12 as [f12 g21 isofg12 isogf12 caller_equ12 callee_equ12 witness_equ12]. destruct is_equ23 as [f23 g32 isofg23 isogf23 caller_equ23 callee_equ23 witness_equ23]. apply mk_contract_equ with (f:=fun x => f23 (f12 x)) (g:=fun x => g21 (g32 x)). + setoid_rewrite isofg12. now setoid_rewr...
Lemma
contract_equ_trans
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "contract", "contract_equ" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
gen_witness_update `{MayProvide ix i} {Ω α} (c : contract i Ω) (ω : Ω) (e : ix α) (x : α) : Ω
:= match proj_p e with | Some e => witness_update c ω e x | None => ω end.
Definition
gen_witness_update
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "MayProvide", "contract" ]
As we compose interfaces and operational semantics, we can easily compose contracts together, by means of the [contractprod] operator. Given [i] and [j] two interfaces, if we can reason about [i] and [j] independently (e.g., the caller obligations of [j] do not vary when we use [i]), then we can compose ...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
gen_caller_obligation `{MayProvide ix i} {Ω α} (c : contract i Ω) (ω : Ω) (e : ix α) : Prop
:= match proj_p e with | Some e => caller_obligation c ω e | None => True end.
Definition
gen_caller_obligation
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "MayProvide", "contract" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
gen_callee_obligation `{MayProvide ix i} {Ω α} (c : contract i Ω) (ω : Ω) (e : ix α) (x : α) : Prop
:= match proj_p e with | Some e => callee_obligation c ω e x | None => True end.
Definition
gen_callee_obligation
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "MayProvide", "contract" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
contractprod `{Provide ix i, Provide ix j} {Ωi Ωj} (ci : contract i Ωi) (cj : contract j Ωj) : contract ix (Ωi * Ωj)
:= {| witness_update := fun (ω : Ωi * Ωj) (α : Type) (e : ix α) (x : α) => (gen_witness_update ci (fst ω) e x, gen_witness_update cj (snd ω) e x) ; caller_obligation := fun (ω : Ωi * Ωj) (α : Type) (e : ix α) => gen_caller_obligation ci (fst ω) e /\ gen_caller_obliga...
Definition
contractprod
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "Provide", "contract", "gen_callee_obligation", "gen_caller_obligation", "gen_witness_update" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
sharedcontractprod `{Provide ix i, Provide ix j} `(ci : contract i Ω) (cj : contract j Ω) : contract ix Ω
:= {| witness_update := fun (ω : Ω) (α : Type) (e : ix α) (x : α) => (* we need to check [i] before [j] because [sharedcontractprod] will be right associative *) match proj_p (i:=i) e with | Some e => witness_update ci ω e x | _ => match proj_p (i:=j) e with | Some ...
Definition
sharedcontractprod
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "Provide", "contract", "gen_callee_obligation", "gen_caller_obligation" ]
FIXME: Should be [StrictProvide2 ix i j]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
store_update (s : Type)
:= fun (x : s) (α : Type) (e : STORE s α) (_ : α) => match e with | Get => x | Put x' => x' end.
Definition
store_update
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "STORE" ]
Finally, and as an example, we define a contract for the interface [STORE s] we discuss in [FreeSpec.Core.Impure]. As a reminder, the interface is defined as follows: << Inductive STORE (s : Type) : interface := | Get : STORE s s | Put (x : s) : STORE s unit. >> For [STORE s], the best witness is the act...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
o_callee_store (s : Type) (x : s) : forall (α : Type), STORE s α -> α -> Prop
:= | get_o_callee (x' : s) (equ : x = x') : o_callee_store s x s Get x' | put_o_callee (x' : s) (u : unit) : o_callee_store s x unit (Put x') u.
Inductive
o_callee_store
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "STORE" ]
Assuming the mutable variable is being initialized prior to any impure computation interpretation, we do not have any obligations over the use of [STORE s] primitives. We will get back to this assertion once we have defined our contract, but in the meantime, we define its callee obligation. The logic ...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
store_specs (s : Type) : contract (STORE s) s
:= {| witness_update := store_update s ; caller_obligation := no_caller_obligation ; callee_obligation := o_callee_store s |}.
Definition
store_specs
Core
theories/Core/Contract.v
[ "Coq", "Setoid", "Morphisms", "ExtLib", "StateMonad", "MonadState", "MonadTrans", "FreeSpec.Core", "Interface", "Impure", "Semantics", "Component" ]
[ "STORE", "contract", "no_caller_obligation", "o_callee_store", "store_update" ]
The actual contract can therefore be defined as follows:
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare (Σ : Type) (α : Type) : Type
:= mk_hoare { pre : Σ -> Prop ; post : Σ -> α -> Σ -> Prop }.
Record
hoare
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[]
* Definition
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare_pure {Σ α} (x : α) : hoare Σ α
:= mk_hoare (fun _ => True) (fun s y s' => x = y /\ s = s').
Definition
hoare_pure
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[ "hoare" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare_bind {Σ α β} (h : hoare Σ α) (k : α -> hoare Σ β) : hoare Σ β
:= mk_hoare (fun s => pre h s /\ (forall x s', post h s x s' -> pre (k x) s')) (fun s x s'' => exists y s', post h s y s' /\ post (k y) s' x s'').
Definition
hoare_bind
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[ "hoare" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare_map {Σ α β} (f : α -> β) (h : hoare Σ α) : hoare Σ β
:= hoare_bind h (fun x => hoare_pure (f x)).
Definition
hoare_map
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[ "hoare", "hoare_bind", "hoare_pure" ]
** Functor
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare_Functor Σ : Functor (hoare Σ)
:= { fmap := fun _ _ => hoare_map }.
Instance
hoare_Functor
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[ "hoare", "hoare_map" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare_apply {Σ α β} (hf : hoare Σ (α -> β)) (h : hoare Σ α) : hoare Σ β
:= hoare_bind hf (fun f => hoare_map f h).
Definition
hoare_apply
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[ "hoare", "hoare_bind", "hoare_map" ]
** Applicative
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare_Applicative Σ : Applicative (hoare Σ)
:= { ap := fun _ _ => hoare_apply ; pure := fun _ => hoare_pure }.
Instance
hoare_Applicative
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[ "hoare", "hoare_apply", "hoare_pure" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare_Monad Σ : Monad (hoare Σ)
:= { ret := @hoare_pure Σ; bind := @hoare_bind Σ }.
Instance
hoare_Monad
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[ "hoare", "hoare_bind", "hoare_pure" ]
** Monad
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
interface_to_hoare `{MayProvide ix i} `(c : contract i Ω) : ix ~> hoare Ω
:= fun a e => {| pre := fun ω => gen_caller_obligation c ω e ; post := fun ω x ω' => gen_callee_obligation c ω e x /\ ω' = gen_witness_update c ω e x |}.
Definition
interface_to_hoare
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[ "MayProvide", "contract", "gen_callee_obligation", "gen_caller_obligation", "gen_witness_update", "hoare" ]
* Reasoning about Programs
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
to_hoare `{MayProvide ix i} `(c : contract i Ω) : impure ix ~> hoare Ω
:= impure_lift (interface_to_hoare c).
Definition
to_hoare
Core
theories/Core/Hoare.v
[ "ExtLib", "Functor", "Applicative", "Monad", "FreeSpec.Core", "Interface", "Impure", "Contract" ]
[ "MayProvide", "contract", "hoare", "impure", "impure_lift", "interface_to_hoare" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare_eq {Σ α} (h1 h2 : hoare Σ α) : Prop
:= | mk_hoare_eq (pre_eq : forall s, pre h1 s <-> pre h2 s) (post_eq : forall s x s', post h1 s x s' <-> post h2 s x s') : hoare_eq h1 h2.
Inductive
hoare_eq
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "hoare" ]
* Equivalence Relation
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
hoare_Equivalence Σ α : @Equivalence (hoare Σ α) hoare_eq.
Next Obligation. easy. Qed.
Instance
hoare_Equivalence
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "hoare", "hoare_eq" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
pre_Proper Σ α : Proper (hoare_eq ==> eq ==> iff) (@pre Σ α).
Next Obligation. add_morphism_tactic. intros h1 h2 equ s. apply equ. Qed.
Instance
pre_Proper
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "hoare_eq" ]
* Proper Instances
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
post_Proper Σ α : Proper (hoare_eq ==> eq ==> eq ==> eq ==> iff) (@post Σ α).
Next Obligation. add_morphism_tactic. intros h1 h2 equ s x s'. apply equ. Qed.
Instance
post_Proper
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "hoare_eq" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
to_hoare_Proper ix i Ω c α MP : Proper (impure_eq ==> hoare_eq) (@to_hoare ix i MP Ω c α).
Next Obligation. add_morphism_tactic. intros p q equ. induction equ. + reflexivity. + constructor. ++ intros ω. cbn in *. setoid_rewrite H. reflexivity. ++ intros ω x ω'. cbn in *. setoid_rewrite H. reflexivity. Qed.
Instance
to_hoare_Proper
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "hoare_eq", "impure_eq", "to_hoare" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
to_hoare_step `{MayProvide ix i} `(c : contract i Ω) `(e : ix a) `(f : a -> impure ix a) `(hpre : pre (to_hoare c (request_then e f)) ω) (x : a) (step : gen_callee_obligation c ω e x) : pre (to_hoare c (f x)) (gen_witness_update c ω e x).
Proof. destruct hpre as [hbefore hafter]. apply hafter. cbn. unfold gen_callee_obligation, gen_witness_update in *. now destruct proj_p. Qed.
Lemma
to_hoare_step
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "MayProvide", "contract", "gen_callee_obligation", "gen_witness_update", "impure", "step", "to_hoare" ]
* General Lemmas
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
to_hoare_pre_bind_assoc `{MayProvide ix i} `(c : contract i Ω) `(p : impure ix a) `(Hp : pre (to_hoare c p) ω) `(f : a -> impure ix b) (run : forall (x : a) (ω' : Ω), post (to_hoare c p) ω x ω' -> pre (to_hoare c (f x)) ω') : pre (to_hoare c (p >>= f)) ω.
Proof. revert ω Hp run. induction p; intros ω Hp run. + now apply run. + cbn in Hp. destruct Hp as [He Hn]. change (request_then e f0 >>= f) with (request_then e (fun x => f0 x >>= f)). split. ++ exact He. ++ intros x ω' Hpost. specialize Hn with x ω'. destruct Hpost. ...
Lemma
to_hoare_pre_bind_assoc
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "MayProvide", "contract", "gen_witness_update", "impure", "to_hoare" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
to_hoare_post_bind_assoc `{MayProvide ix i} `(c : contract i Ω) `(p : impure ix a) `(f : a -> impure ix b) `(Hp : post (to_hoare c (impure_bind p f)) ω x ω') : exists y ω'', post (to_hoare c p) ω y ω'' /\ post (to_hoare c $ f y) ω'' x ω'.
Proof. revert ω Hp. induction p; intros ω Hp. + now exists x0, ω. + destruct Hp as [y [ω'' [Hp1 Hp2]]]. apply H0 in Hp2. destruct Hp2 as [z [ω''' [Hp2 Hp3]]]. exists z, ω'''. split; [| apply Hp3]. exists y, ω''. now split. Qed.
Lemma
to_hoare_post_bind_assoc
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "MayProvide", "contract", "impure", "impure_bind", "to_hoare" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
to_hoare_contractprod `{Provide ix i, Provide ix j} `(ci : contract i Ωi) `(cj : contract j Ωj) `(p : impure ix a) `(prei : pre (to_hoare ci p) ωi) `(prej : pre (to_hoare cj p) ωj) : pre (to_hoare (ci * cj) p) (ωi, ωj).
Proof. revert ωi prei ωj prej. induction p; intros ωi prei ωj prej. + auto. + destruct prei as [calleri Hcalleei]. destruct prej as [callerj Hcalleej]. split. ++ now split. ++ intros x [ωi' ωj'] [[calleei calleej] equωs]. cbn in equωs. inversion equωs; subst. apply H3. ...
Lemma
to_hoare_contractprod
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "Provide", "contract", "impure", "to_hoare" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
contract_equ_pre `(c1 : contract i Ω1) `(c2 : contract i Ω2) `(equ : contract_equ c1 c2) (ω1 : Ω1) `(p : impure i a) : pre (to_hoare c1 p) ω1 <-> pre (to_hoare c2 p) (contract_iso_lr equ ω1).
Proof. induction equ. revert ω1. induction p; intros ω1. + now split. + cbn. rewrite (caller_equ ω1 β e). setoid_rewrite (callee_equ ω1 β e). split. ++ intros [ocaller onext]. split; auto. intros x ω1' [ocallee owitness]. rewrite owitness. rewrite <- witness_equ. ...
Lemma
contract_equ_pre
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "contract", "contract_equ", "contract_iso_lr", "impure", "to_hoare" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
contract_equ_post `(c1 : contract i Ω1) `(c2 : contract i Ω2) `(equ : contract_equ c1 c2) (ω1 ω1' : Ω1) `(p : impure i a) (x : a) (post1 : post (to_hoare c1 p) ω1 x ω1') : post (to_hoare c2 p) (contract_iso_lr equ ω1) x (contract_iso_lr equ ω1').
Proof. induction equ. cbn in *. revert x ω1 ω1' post1. induction p; intros y ω1 ω1' post1. + destruct post1 as [xequ ω1equ]. cbn. now subst. + cbn in post1. destruct post1 as [x [ω1'' [[ocallee owitness] post1]]]. eapply H in post1. exists x. exists (f ω1''). split; auto. cbn...
Lemma
contract_equ_post
Core
theories/Core/HoareFacts.v
[ "FreeSpec.Core", "Interface", "ImpureFacts", "Contract", "Hoare" ]
[ "contract", "contract_equ", "contract_iso_lr", "impure", "repeat", "to_hoare" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure (i : interface) (α : Type) : Type
:= | local (x : α) : impure i α | request_then {β} (e : i β) (f : β -> impure i α) : impure i α.
Inductive
impure
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "interface" ]
The [impure] monad is an inductive datatype with two parameters: the interface [i] to be used, and the type [α] of the result of the computation. The fact that [impure] is inductive rather than co-inductive means it is not possible to describe infinite computations. This also means it is possible to in...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_bind {i α β} (p : impure i α) (f : α -> impure i β) : impure i β
:= match p with | local x => f x | request_then e g => request_then e (fun x => impure_bind (g x) f) end.
Fixpoint
impure_bind
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "impure" ]
We then provide the necessary instances of the <<coq-prelude>> Monad typeclasses hierarchy.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_map {i α β} (f : α -> β) (p : impure i α) : impure i β
:= impure_bind p (fun x => local (f x)).
Definition
impure_map
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "impure", "impure_bind" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_Functor i : Functor (impure i)
:= { fmap := @impure_map i }.
Instance
impure_Functor
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "impure", "impure_map" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_pure {i α} (x : α) : impure i α
:= local x.
Definition
impure_pure
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "impure" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_apply {i α β} (p : impure i (α -> β)) (q : impure i α) : impure i β
:= impure_bind p (fun f => fmap f q).
Definition
impure_apply
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "impure", "impure_bind" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_Applicative i : Applicative (impure i)
:= { pure := @impure_pure i ; ap := @impure_apply i }.
Instance
impure_Applicative
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "impure", "impure_apply", "impure_pure" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_Monad (i : interface) : Monad (impure i)
:= { ret := @impure_pure i ; bind := @impure_bind i }.
Instance
impure_Monad
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "impure", "impure_bind", "impure_pure", "interface" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
request `{Provide ix i} {α} (e : i α) : impure ix α
:= request_then (inj_p e) (fun x => pure x).
Definition
request
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "Provide", "impure" ]
FreeSpec users shall not use the [impure] monad constructors directly. The [pure] function from the [Applicative] typeclass allows for defining pure computations which do not depend on any impure primitive. The [bind] function from the [Monad] typeclass allows for seamlessly combine impure computation...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
store_monad_state (s : Type) (ix : interface) `{Provide ix (STORE s)} : MonadState s (impure ix)
:= { put := fun (x : s) => request (Put x) ; get := request Get }.
Instance
store_monad_state
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "Provide", "STORE", "impure", "interface", "request" ]
Note: there have been attempts to turn [request] into a typeclass function (to seamlessly use [request] with a [MonadTrans] instance such as [state_t]). The reason why it has not been kept into the codebase is that the flexibility it gives for writing code has a real impact on the verification process. ...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_lift `{Monad m} `(l : i ~> m) : impure i ~> m
:= fix aux a (p : impure i a) := match p with | local x => ret x | request_then e f => let* x := l _ e in aux a (f x) end.
Definition
impure_lift
Core
theories/Core/Impure.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "MonadState", "FreeSpec.Core", "Interface" ]
[ "impure" ]
* Lift
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_eq {i α} : impure i α -> impure i α -> Prop
:= (** - Two impure computations are equivalent if and only if they compute the exact same term (wrt. Coq [eq] function). *) | local_eq (x : α) : impure_eq (local x) (local x) (** - Two computations which consist in requesting the interpretation of an primitive and passing the result to a monadic continu...
Inductive
impure_eq
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "function_eq", "impure" ]
The definition of [impure_equiv] is two-fold.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_Equivalence i α : @Equivalence (impure i α) impure_eq := {}.
Next Obligation. intros p. induction p; constructor. intros x. apply H. Qed.
Instance
impure_Equivalence
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "impure", "impure_eq" ]
The definition of [impure_equiv] is very similar to [eq], with the exception of the treatment of the continuation. There is no much effort to put into proving this is indeed a proper equivalence.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
change_request_then
:= match goal with | |- (request_then ?e ?f === request_then ?e ?g)%impure => let R := fresh "R" in assert (R: function_eq impure_eq f g); [ intros ?x | rewrite R; clear R ] end.
Ltac
change_request_then
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "function_eq", "impure", "impure_eq" ]
** Proper Instances
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
change_impure_bind
:= match goal with | |- (impure_bind ?e ?f === impure_bind ?e ?g)%impure => let R := fresh "R" in assert (R: function_eq impure_eq f g); [ intros ?x | now rewrite R ] end.
Ltac
change_impure_bind
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "function_eq", "impure", "impure_bind", "impure_eq" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
request_then_Proper i α β : Proper (eq ==> function_eq impure_eq ==> impure_eq) (@request_then i α β).
Next Obligation. add_morphism_tactic. intros e f g equ. constructor. intros y. specialize (equ y). now rewrite equ. Qed.
Instance
request_then_Proper
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "function_eq", "impure_eq" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_bind_Proper i α β : Proper (impure_eq ==> function_eq impure_eq ==> impure_eq) (@impure_bind i α β).
Next Obligation. add_morphism_tactic. intros x y equ1 f g equ2. induction equ1. + cbn. now rewrite (equ2 x). + cbn. constructor. intros x. apply H. Qed.
Instance
impure_bind_Proper
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "function_eq", "impure_bind", "impure_eq" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_map_Proper i α β : Proper (function_eq eq ==> impure_eq ==> impure_eq) (@impure_map i α β).
Proof. add_morphism_tactic. intros f g equf p q equp. unfold impure_map. rewrite equp. change_impure_bind. now rewrite equf. Qed.
Instance
impure_map_Proper
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "change_impure_bind", "function_eq", "impure_eq", "impure_map" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_apply_Proper i α β : Proper (impure_eq ==> impure_eq ==> impure_eq) (@impure_apply i α β).
Next Obligation. add_morphism_tactic. intros p q equ1 r s equ2. unfold impure_apply. rewrite equ1. change_impure_bind. cbn. now rewrite equ2. Qed.
Instance
impure_apply_Proper
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "change_impure_bind", "impure_apply", "impure_eq" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_bind_local {i α} (p : impure i α) : (impure_bind p (fun x => local x) === p)%impure.
Proof. induction p. + reflexivity. + cbn. change_request_then; [| reflexivity]. now rewrite H. Qed.
Lemma
impure_bind_local
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "change_request_then", "impure", "impure_bind" ]
Monadic laws as defined in [ExtLib.Structures.MonadLaws] an related are expressed against [eq], which is too strong in the general case, and in [impure]’s case in particular. We could prove them using the functional extensionality axiom, but we’d rather provide an alternative implementaiton of these law...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
impure_bind_assoc {i α β δ} (p : impure i α) (f : α -> impure i β) (g : β -> impure i δ) : (impure_bind (impure_bind p f) g === impure_bind p (fun x => impure_bind (f x) g))%impure.
Proof. induction p; [reflexivity |]. cbn. change_request_then; auto. reflexivity. Qed.
Lemma
impure_bind_assoc
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "change_request_then", "impure", "impure_bind" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
bind_request_then_assoc `(e : i a) `(f : a -> impure i b) `(g : b -> impure i c) : request_then e f >>= g = request_then e (fun x => f x >>= g).
Proof. reflexivity. Qed.
Lemma
bind_request_then_assoc
Core
theories/Core/ImpureFacts.v
[ "FreeSpec.Core", "Impure" ]
[ "impure" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
when {m : Type -> Type} `{Monad m} (cond : bool) `(p : m a) : m unit
:= if cond then (p;; pure tt) else pure tt.
Definition
when
Core
theories/Core/Init.v
[ "Coq", "Eqdep" ]
[]
* Utils Functions
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
ssubst
:= lazymatch goal with | [ H : existT _ _ _ = existT _ _ _ |- _ ] => apply Eqdep.EqdepTheory.inj_pair2 in H; ssubst | [ |- _] => subst end.
Ltac
ssubst
Core
theories/Core/Init.v
[ "Coq", "Eqdep" ]
[]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
"m '~>' n"
:= (forall (α : Type), m α -> n α) (at level 80, no associativity) : type_scope.
Notation
m '~>' n
Core
theories/Core/Init.v
[ "Coq", "Eqdep" ]
[]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
function_eq {a b} (r : b -> b -> Prop) (f g : a -> b) : Prop
:= forall (x : a), r (f x) (g x).
Definition
function_eq
Core
theories/Core/Init.v
[ "Coq", "Eqdep" ]
[]
* Generalizable Functions Equality
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
function_eq_Equivalence a `(Equivalence b r) : @Equivalence (a -> b) (function_eq r).
Next Obligation. now intros f x. Qed.
Instance
function_eq_Equivalence
Core
theories/Core/Init.v
[ "Coq", "Eqdep" ]
[ "function_eq" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
instrument Ω i
:= (stateT Ω (state (semantics i))).
Notation
instrument
Core
theories/Core/Instrument.v
[ "ExtLib", "StateMonad", "MonadTrans", "FreeSpec.Core", "Interface", "Semantics", "Contract" ]
[ "semantics" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
interface_to_instrument `{MayProvide ix i} `(c : contract i Ω) : ix ~> instrument Ω ix
:= fun a e => let* x := lift $ interface_to_state _ e in modify (fun ω => gen_witness_update c ω e x);; ret x.
Definition
interface_to_instrument
Core
theories/Core/Instrument.v
[ "ExtLib", "StateMonad", "MonadTrans", "FreeSpec.Core", "Interface", "Semantics", "Contract" ]
[ "MayProvide", "contract", "gen_witness_update", "instrument", "interface_to_state" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
to_instrument `{MayProvide ix i} `(c : contract i Ω) : impure ix ~> instrument Ω ix
:= impure_lift $ interface_to_instrument c.
Definition
to_instrument
Core
theories/Core/Instrument.v
[ "ExtLib", "StateMonad", "MonadTrans", "FreeSpec.Core", "Interface", "Semantics", "Contract" ]
[ "MayProvide", "contract", "impure", "impure_lift", "instrument", "interface_to_instrument" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
instrument_to_state {i} `(ω : Ω) : instrument Ω i ~> state (semantics i)
:= fun a instr => fst <$> runStateT instr ω.
Definition
instrument_to_state
Core
theories/Core/Instrument.v
[ "ExtLib", "StateMonad", "MonadTrans", "FreeSpec.Core", "Interface", "Semantics", "Contract" ]
[ "instrument", "semantics" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
instrument_to_state_eval_morphism `{MayProvide ix i} `(c : contract i Ω) `(p : impure ix a) (ω : Ω) : forall (sem : semantics ix), evalState (to_state p) sem = fst (evalState (runStateT (to_instrument c p) ω) sem).
Proof. unfold evalState. revert ω. induction p. + reflexivity. + intros ω sem. cbn -[gen_witness_update]. destruct run_effect; cbn. now rewrite H0 with (ω := gen_witness_update c ω e β0). Qed.
Lemma
instrument_to_state_eval_morphism
Core
theories/Core/InstrumentFacts.v
[ "ExtLib", "StateMonad", "FreeSpec.Core", "Contract", "HoareFacts", "SemanticsFacts", "Instrument" ]
[ "MayProvide", "contract", "gen_witness_update", "impure", "run_effect", "semantics", "to_instrument", "to_state" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
instrument_to_state_exec_morphism `{MayProvide ix i} `(c : contract i Ω) `(p : impure ix a) (ω : Ω) : forall (sem : semantics ix), execState (to_state p) sem = execState (runStateT (to_instrument c p) ω) sem.
Proof. unfold execState. revert ω. induction p. + reflexivity. + intros ω sem. cbn -[gen_witness_update]. destruct run_effect; cbn. now rewrite H0 with (ω := gen_witness_update c ω e β0). Qed.
Lemma
instrument_to_state_exec_morphism
Core
theories/Core/InstrumentFacts.v
[ "ExtLib", "StateMonad", "FreeSpec.Core", "Contract", "HoareFacts", "SemanticsFacts", "Instrument" ]
[ "MayProvide", "contract", "gen_witness_update", "impure", "run_effect", "semantics", "to_instrument", "to_state" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
instrument_satisfies_hoare `{MayProvide ix i} `(c : contract i Ω) `(p : impure ix a) `(comp : compliant_semantics c ω sem) : pre (to_hoare c p) ω -> post (to_hoare c p) ω (fst $ evalState (runStateT (to_instrument c p) ω) sem) (snd $ evalState (runStateT (to_instrument c ...
Proof. revert comp. revert ω. revert sem. induction p; intros sem ω comp. + cbn. intros _. split; reflexivity. + intros pre. cbn -[interface_to_hoare] in pre. destruct pre as [He Hf]. cbn in He. inversion comp; subst. pose proof He as He'. apply o_callee in He. cbn. exist...
Lemma
instrument_satisfies_hoare
Core
theories/Core/InstrumentFacts.v
[ "ExtLib", "StateMonad", "FreeSpec.Core", "Contract", "HoareFacts", "SemanticsFacts", "Instrument" ]
[ "MayProvide", "compliant_semantics", "contract", "eval_effect", "gen_witness_update", "impure", "interface_to_hoare", "repeat", "run_effect_equation", "to_hoare", "to_instrument" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
instrument_preserves_compliance `{MayProvide ix i} `(c : contract i Ω) `(p : impure ix a) `(comp : compliant_semantics c ω sem) : pre (to_hoare c p) ω -> compliant_semantics c (snd $ evalState (runStateT (to_instrument c p) ω) sem) (execState (runStateT (to_instrument c p) ω) sem)...
Proof. revert comp. revert ω. revert sem. induction p; intros sem ω comp pre. + auto. + cbn in pre. destruct pre as [He Hn]. specialize Hn with (eval_effect sem e) (gen_witness_update (H := H) c ω e (eval_effect sem e)). inversion comp; subst. assert (Hn' : pre (to_hoare c...
Lemma
instrument_preserves_compliance
Core
theories/Core/InstrumentFacts.v
[ "ExtLib", "StateMonad", "FreeSpec.Core", "Contract", "HoareFacts", "SemanticsFacts", "Instrument" ]
[ "MayProvide", "compliant_semantics", "contract", "eval_effect", "exec_effect", "gen_witness_update", "impure", "run_effect_equation", "to_hoare", "to_instrument" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
interface
:= Type -> Type.
Definition
interface
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[]
Following the definition of the <<operational>> package, interfaces in FreeSpec are parameterized inductive types whose terms purposely describe the primitives the interface provides.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iempty : interface
:= .
Inductive
iempty
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "interface" ]
Given [i : interface], a term of type [i α] identifies a primitive of [i] expected to produce a result of type [α]. The simpler interface is the empty interface, which provides no primitives whatsoever.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
STORE (s : Type) : interface
:= | Get : STORE s s | Put (x : s) : STORE s unit.
Inductive
STORE
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "interface" ]
Another example of general-purpose interface we can define is the [STORE s] interface, where [s] is a type for a state, and [STORE s] allows for manipulating a global, mutable variable of type [s] within an impure computation.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
MayProvide (ix i : interface) : Type
:= { proj_p {α} (e : ix α) : option (i α) }.
Class
MayProvide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "interface" ]
When defining general-purpose impure computations that we expect to reuse in different context, we want to leave the interface as a parameter, and rather express the constraints in terms of interface availability. We tackle this challenge by means of _interface composites_. - We say an interface compo...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
Provide (ix i : interface) `{MayProvide ix i} : Type
:= { inj_p {α} (e : i α) : ix α ; proj_inj_p_equ {α} (e : i α) : proj_p (inj_p e) = Some e }.
Class
Provide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "MayProvide", "interface" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
default_MayProvide (i j : interface) : MayProvide i j|1000
:= { proj_p := fun _ _ => None }.
Instance
default_MayProvide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "MayProvide", "interface" ]
We provide a default instance for [MayProvide] in the form of a function [proj_p] which always return [None]. We give to this default instance a ridiculously high priority number to ensure it is selected only if no other instances are found.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
Distinguish (ix i j : interface) `{Provide ix i, MayProvide ix j} : Prop
:= { distinguish : forall {α} (e : i α), proj_p (i := j) (inj_p (ix := ix) e) = None }.
Class
Distinguish
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "MayProvide", "Provide", "interface" ]
It is expected that, for an interface composite [ix] which provides [i] and may provide [j], [inj_p] and [proj_p] do not mix up [i] and [j] primitives. That is, injecting a primitive [e] of [i] inside [ix], then projecting the resulting primitive into [j] returns [None] as long as [i] and [j] are two di...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus (i j : interface) (α : Type)
:= | in_left (e : i α) : iplus i j α | in_right (e : j α) : iplus i j α.
Inductive
iplus
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "interface" ]
We provide the [iplus] operator to compose interface together. That is, [iplus] can be used to build _concrete_ (as opposed to polymorphic) interface composite.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
refl_MayProvide (i : interface) : MayProvide i i
:= { proj_p := fun _ e => Some e }.
Instance
refl_MayProvide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "MayProvide", "interface" ]
For [iplus] to be used seamlessly as a concrete interface composite, we provide the necessary instances for the [MayProvide], [Provide] and [Distinguish] type classes. Note that these instances always prefer the left operand of [iplus]. For instance, considering a situation where there is an instance fo...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
refl_Provide (i : interface) : @Provide i i (refl_MayProvide i)
:= { inj_p := fun (a : Type) (e : i a) => e }.
Instance
refl_Provide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Provide", "interface", "refl_MayProvide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_left_MayProvide (ix i j : interface) `{MayProvide ix i} : MayProvide (ix + j) i
:= { proj_p := fun _ e => match e with | in_left e => proj_p e | _ => None end }.
Instance
iplus_left_MayProvide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "MayProvide", "interface" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_left_Provide (ix i j : interface) `{Provide ix i} : @Provide (ix + j) i (iplus_left_MayProvide ix i j) := { inj_p := fun (a : Type) (e : i a) => in_left (inj_p e) }.
Next Obligation. now rewrite proj_inj_p_equ. Qed.
Instance
iplus_left_Provide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Provide", "interface", "iplus_left_MayProvide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_right_MayProvide (i jx j : interface) `{MayProvide jx j} : MayProvide (i + jx) j
:= { proj_p := fun _ e => match e with | in_right e => proj_p e | _ => None end }.
Instance
iplus_right_MayProvide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "MayProvide", "interface" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_right_Provide (i jx j : interface) `{Provide jx j} : @Provide (i + jx) j (iplus_right_MayProvide i jx j) := { inj_p := fun _ e => in_right (inj_p e) }.
Next Obligation. now rewrite proj_inj_p_equ. Qed.
Instance
iplus_right_Provide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Provide", "interface", "iplus_right_MayProvide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
find_may_provide
:= eapply refl_MayProvide + (eapply iplus_left_MayProvide; find_may_provide) + (eapply iplus_right_MayProvide; find_may_provide).
Ltac
find_may_provide
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "iplus_left_MayProvide", "iplus_right_MayProvide", "refl_MayProvide" ]
By default, Coq's inference algorithm for type classe instances inference is a depth-first search. This is not without consequence in our case. For instance, if we consider the search of an instance for [MayProvide (i + j) j], Coq will first try [iplus_right_MayProvide] (as explained previously), meanin...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
refl_Distinguish (i j : interface) : @Distinguish i i j (@refl_MayProvide i) (@refl_Provide i) (@default_MayProvide i j).
Instance
refl_Distinguish
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Distinguish", "default_MayProvide", "interface", "refl_MayProvide", "refl_Provide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_left_default_Distinguish (ix jx i j : interface) `{M1 : MayProvide ix i} `{P1 : @Provide ix i M1} : @Distinguish (ix + jx) i j (@iplus_left_MayProvide ix i jx M1) (@iplus_left_Provide ix i jx M1 P1) (@default_MayProvide _ j).
Instance
iplus_left_default_Distinguish
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Distinguish", "MayProvide", "Provide", "default_MayProvide", "interface", "iplus_left_MayProvide", "iplus_left_Provide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_right_default_Distinguish (ix jx i j : interface) `{M1 : MayProvide jx i} `{P1 : @Provide jx i M1} : @Distinguish (ix + jx) i j (@iplus_right_MayProvide ix jx i M1) (@iplus_right_Provide ix jx i M1 P1) (@default_MayProvide _ j).
Instance
iplus_right_default_Distinguish
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Distinguish", "MayProvide", "Provide", "default_MayProvide", "interface", "iplus_right_MayProvide", "iplus_right_Provide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_left_may_right_Distinguish (ix jx i j : interface) `{M1 : MayProvide ix i} `{P1 : @Provide ix i M1} `{M2 : MayProvide jx j} : @Distinguish (ix + jx) i j (@iplus_left_MayProvide ix i jx M1) (@iplus_left_Provide ix i jx M1 P1) (@iplus_right_MayProvide ix jx j ...
Instance
iplus_left_may_right_Distinguish
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Distinguish", "MayProvide", "Provide", "interface", "iplus_left_MayProvide", "iplus_left_Provide", "iplus_right_MayProvide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_right_may_left_Distinguish (ix jx i j : interface) `{M1 : MayProvide jx i} `{P1 : @Provide jx i M1} `{M2 : MayProvide ix j} : @Distinguish (ix + jx) i j (@iplus_right_MayProvide ix jx i M1) (@iplus_right_Provide ix jx i M1 P1) (@iplus_left_MayProvide ix j jx...
Instance
iplus_right_may_left_Distinguish
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Distinguish", "MayProvide", "Provide", "interface", "iplus_left_MayProvide", "iplus_right_MayProvide", "iplus_right_Provide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_left_distinguish_left_Distinguish (ix jx i j : interface) `{M1 : MayProvide ix i} `{P1 : @Provide ix i M1} `{M2 : MayProvide ix j} `{@Distinguish ix i j M1 P1 M2} : @Distinguish (ix + jx) i j (@iplus_left_MayProvide ix i jx M1) (@iplus_left_Provide ix i jx M1 P1) ...
Next Obligation. apply distinguish. Defined.
Instance
iplus_left_distinguish_left_Distinguish
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Distinguish", "MayProvide", "Provide", "interface", "iplus_left_MayProvide", "iplus_left_Provide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iplus_right_distinguish_right_Distinguish (ix jx i j : interface) `{M1 : MayProvide jx i} `{P1 : @Provide jx i M1} `{M2 : MayProvide jx j} `{@Distinguish jx i j M1 P1 M2} : @Distinguish (ix + jx) i j (@iplus_right_MayProvide ix jx i M1) (@iplus_right_Provide ix jx i M1 P1) ...
Next Obligation. apply distinguish. Defined.
Instance
iplus_right_distinguish_right_Distinguish
Core
theories/Core/Interface.v
[ "FreeSpec.Core", "Init", "Coq", "Program" ]
[ "Distinguish", "MayProvide", "Provide", "interface", "iplus_right_MayProvide", "iplus_right_Provide" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
semantics (i : interface) : Type
:= | mk_semantics (f : forall (α : Type), i α -> α * semantics i) : semantics i.
CoInductive
semantics
Core
theories/Core/Semantics.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "Monad", "StateMonad", "FreeSpec.Core", "Interface", "Impure" ]
[ "interface" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
iempty_semantics : semantics iempty
:= mk_semantics (fun α (e : iempty α) => match e with end).
Definition
iempty_semantics
Core
theories/Core/Semantics.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "Monad", "StateMonad", "FreeSpec.Core", "Interface", "Impure" ]
[ "iempty", "semantics" ]
Thus, a [semantics] does not only compute a result for a primitive, but also provides a new semantics. This is necessary to model impurity: the same primitive may or may not return the same result when called several times. As for interfaces, the simpler [semantics] is the operational semantics for ...
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
store {s} (init : s) : semantics (STORE s)
:= mk_semantics (fun α (e : STORE s α) => match e with | Get => (init, store init) | Put next => (tt, store next) end).
CoFixpoint
store
Core
theories/Core/Semantics.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "Monad", "StateMonad", "FreeSpec.Core", "Interface", "Impure" ]
[ "STORE", "semantics" ]
We also provide a semantics for the [STORE s] interface:
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
run_effect {i α} (sem : semantics i) (e : i α) : α * semantics i
:= match sem with mk_semantics f => f α e end.
Definition
run_effect
Core
theories/Core/Semantics.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "Monad", "StateMonad", "FreeSpec.Core", "Interface", "Impure" ]
[ "semantics" ]
We provide several helper functions to interpret primitives with semantics.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
eval_effect {i α} (sem : semantics i) (e : i α) : α
:= fst (run_effect sem e).
Definition
eval_effect
Core
theories/Core/Semantics.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "Monad", "StateMonad", "FreeSpec.Core", "Interface", "Impure" ]
[ "run_effect", "semantics" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
exec_effect {i α} (sem : semantics i) (e : i α) : semantics i
:= snd (run_effect sem e).
Definition
exec_effect
Core
theories/Core/Semantics.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "Monad", "StateMonad", "FreeSpec.Core", "Interface", "Impure" ]
[ "run_effect", "semantics" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
run_effect_equation {i α} (sem : semantics i) (e : i α) : run_effect sem e = (eval_effect sem e, exec_effect sem e).
Proof. unfold eval_effect, exec_effect. destruct run_effect; reflexivity. Qed.
Lemma
run_effect_equation
Core
theories/Core/Semantics.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "Monad", "StateMonad", "FreeSpec.Core", "Interface", "Impure" ]
[ "eval_effect", "exec_effect", "run_effect", "semantics" ]
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663
semprod {i j} (sem_i : semantics i) (sem_j : semantics j) : semantics (i + j)
:= mk_semantics (fun _ e => match e with | in_left e => let (x, out) := run_effect sem_i e in (x, semprod out sem_j) | in_right e => let (x, out) := run_effect sem_j e in (x, semprod s...
CoFixpoint
semprod
Core
theories/Core/Semantics.v
[ "Coq", "Program", "Setoid", "Morphisms", "ExtLib", "Monad", "StateMonad", "FreeSpec.Core", "Interface", "Impure" ]
[ "run_effect", "semantics" ]
Besides, and similarly to interfaces, operational semantics can and should be composed together. To that end, we provide the [semprod] operator.
https://github.com/lthms/FreeSpec
d4e2f3a3fc7e82effddca202a8b0210dbbcf3663