Merge pull request #80 from VariantSync/module-structure-refactorings

Module structure refactorings

Author: pmbittner

.gitignore

@@ -5,6 +5,9 @@
 *.#*
 .dir-locals.el
 
+# emacs' agda mode
+src/agda2-mode*
+
 # build
 src/cc
 src/Main

default.nix

@@ -9,7 +9,7 @@
     },
 }:
 pkgs.agdaPackages.mkDerivation {
-  version = "1.0";
+  version = "2.0";
   pname = "Vatras";
   src = with pkgs.lib.fileset;
     toSource {

src/Vatras/Lang/2CC.lagda.md

@@ -3,23 +3,19 @@
 ## Module
 
 ```agda
-open import Vatras.Framework.Definitions
-module Vatras.Lang.2CC where
+open import Vatras.Framework.Definitions using (𝔽; 𝔸; atoms; 𝔼; ℂ)
+module Vatras.Lang.2CC (Dimension : 𝔽) where
 ```
 
 ## Imports
 
 ```agda
-open import Data.Bool using (Bool; true; false; if_then_else_)
-open import Data.List
-  using (List; []; _∷_; lookup)
-  renaming (map to mapl)
-open import Data.Product using (_,_)
-open import Function using (id)
+open import Data.Bool using (Bool; if_then_else_)
+open import Data.List as List using (List)
 open import Size using (Size; ↑_; ∞)
 
 open import Vatras.Framework.Variants as V using (Rose)
-open import Vatras.Framework.VariabilityLanguage
+open import Vatras.Framework.VariabilityLanguage using (𝔼-Semantics; VariabilityLanguage; ⟪_,_,_⟫)
 ```
 
 ## Syntax
@@ -31,9 +27,9 @@ or a binary choice `D ⟨ l , r ⟩` between two sub-expressions `l` and `r`, wh
 to identify the choice upon configuration.
 Dimensions `D` can be of any given type `Dimension : 𝔽`.
 ```agda
-data 2CC (Dimension : 𝔽) : Size → 𝔼 where
-   _-<_>- : ∀ {i A} → atoms A → List (2CC Dimension i A) → 2CC Dimension (↑ i) A
-   _⟨_,_⟩ : ∀ {i A} → Dimension → 2CC Dimension i A → 2CC Dimension i A → 2CC Dimension (↑ i) A
+data 2CC : Size → 𝔼 where
+   _-<_>- : ∀ {i A} → atoms A → List (2CC i A) → 2CC (↑ i) A
+   _⟨_,_⟩ : ∀ {i A} → Dimension → 2CC i A → 2CC i A → 2CC (↑ i) A
 ```
 
 ## Semantics
@@ -47,175 +43,16 @@ We define `true` to mean choosing the left alternative and `false` to choose the
 Defining it the other way around is also possible but we have to pick one definition and stay consistent.
 We choose this order to follow the known _if c then a else b_ pattern where the evaluation of a condition _c_ to true means choosing the then-branch, which is the left one.
 ```agda
-Configuration : (Dimension : 𝔽) → ℂ
-Configuration Dimension = Dimension → Bool
+Configuration : ℂ
+Configuration = Dimension → Bool
 
-⟦_⟧ : ∀ {i : Size} {Dimension : 𝔽} → 𝔼-Semantics (Rose ∞) (Configuration Dimension) (2CC Dimension i)
-⟦ a -< cs >-  ⟧ c = a V.-< mapl (λ e → ⟦ e ⟧ c) cs >-
+⟦_⟧ : ∀ {i : Size} → 𝔼-Semantics (Rose ∞) Configuration (2CC i)
+⟦ a -< cs >-  ⟧ c = a V.-< List.map (λ e → ⟦ e ⟧ c) cs >-
 ⟦ D ⟨ l , r ⟩ ⟧ c =
   if c D
   then ⟦ l ⟧ c
   else ⟦ r ⟧ c
 
-2CCL : ∀ {i : Size} (Dimension : 𝔽) → VariabilityLanguage (Rose ∞)
-2CCL {i} Dimension = ⟪ 2CC Dimension i , Configuration Dimension , ⟦_⟧ ⟫
-```
-
-In the following, we prove some interesting properties about binary choice calculus,
-known from the respective papers.
-
-```agda
-module _ {Dimension : 𝔽} where
-```
-
-## Properties
-
-Some transformation rules:
-```agda
-  open Data.List using ([_])
-  open import Data.List.Properties using (map-∘; map-cong)
-  open import Data.Nat using (ℕ)
-  open import Data.Vec as Vec using (Vec; toList; zipWith)
-  import Data.Vec.Properties as Vec
-  import Vatras.Util.Vec as Vec
-
-  open import Relation.Binary.PropositionalEquality as Eq using (_≡_; refl; _≗_)
-
-  module Properties where
-    open import Vatras.Framework.Relation.Expression (Rose ∞)
-
-    module _ {A : 𝔸} where
-      {-|
-      Given a choice between two artifacts with the same atom 'a',
-      we can factor out this atom 'a' outside of the choice because no matter
-      how we configure the choice, the resulting expression will always have 'a'
-      at the top.
-      -}
-      choice-factoring : ∀ {i} {D : Dimension} {a : atoms A} {n : ℕ}
-        → (xs ys : Vec (2CC Dimension i A) n)
-          ------------------------------------------------
-        → 2CCL Dimension ⊢
-              D ⟨ a -< toList xs >- , a -< toList ys >- ⟩
-            ≣₁ a -< toList (zipWith (D ⟨_,_⟩) xs ys) >-
-      choice-factoring {i} {D} {a} {n} xs ys c =
-          ⟦ D ⟨ a -< toList xs >- , a -< toList ys >- ⟩ ⟧ c
-        ≡⟨⟩
-          (if c D then ⟦ a -< toList xs >- ⟧ c else ⟦ a -< toList ys >- ⟧ c)
-        ≡⟨ lemma (c D) ⟩
-          a V.-< toList (zipWith (λ x y → if c D then ⟦ x ⟧ c else ⟦ y ⟧ c) xs ys) >-
-        ≡⟨⟩
-          a V.-< toList (zipWith (λ x y → ⟦ D ⟨ x , y ⟩ ⟧ c) xs ys) >-
-        ≡⟨ Eq.cong (a V.-<_>-) (Eq.cong toList (Vec.map-zipWith (λ e → ⟦ e ⟧ c) (D ⟨_,_⟩) xs ys)) ⟨
-          a V.-< toList (Vec.map (λ e → ⟦ e ⟧ c) (zipWith (D ⟨_,_⟩) xs ys)) >-
-        ≡⟨ Eq.cong (a V.-<_>-) (Vec.toList-map (λ e → ⟦ e ⟧ c) (zipWith (D ⟨_,_⟩) xs ys)) ⟩
-          a V.-< mapl (λ e → ⟦ e ⟧ c) (toList (zipWith (D ⟨_,_⟩) xs ys)) >-
-        ≡⟨⟩
-          ⟦ a -< toList (zipWith (D ⟨_,_⟩) xs ys) >- ⟧ c
-        ∎
-        where
-          open Eq.≡-Reasoning
-          lemma : (b : Bool) →
-              (if b then ⟦ a -< toList xs >- ⟧ c else ⟦ a -< toList ys >- ⟧ c)
-            ≡ a V.-< toList (zipWith (λ x y → if b then ⟦ x ⟧ c else ⟦ y ⟧ c) xs ys) >-
-          lemma false =
-              (if false then ⟦ a -< toList xs >- ⟧ c else ⟦ a -< toList ys >- ⟧ c)
-            ≡⟨⟩
-              ⟦ a -< toList ys >- ⟧ c
-            ≡⟨⟩
-              a V.-< mapl (λ e → ⟦ e ⟧ c) (toList ys) >-
-            ≡⟨ Eq.cong (a V.-<_>-) (Vec.toList-map (λ e → ⟦ e ⟧ c) ys) ⟨
-              a V.-< toList (Vec.map (λ y → ⟦ y ⟧ c) ys) >-
-            ≡⟨ Eq.cong (a V.-<_>-) (Eq.cong toList (Vec.zipWith₂ (λ y → ⟦ y ⟧ c) xs ys)) ⟨
-              a V.-< toList (zipWith (λ x y → ⟦ y ⟧ c) xs ys) >-
-            ≡⟨⟩
-              a V.-< toList (zipWith (λ x y → if false then ⟦ x ⟧ c else ⟦ y ⟧ c) xs ys) >-
-            ∎
-          lemma true =
-              (if true then ⟦ a -< toList xs >- ⟧ c else ⟦ a -< toList ys >- ⟧ c)
-            ≡⟨⟩
-              ⟦ a -< toList xs >- ⟧ c
-            ≡⟨⟩
-              a V.-< mapl (λ e → ⟦ e ⟧ c) (toList xs) >-
-            ≡⟨ Eq.cong (a V.-<_>-) (Vec.toList-map (λ e → ⟦ e ⟧ c) xs) ⟨
-              a V.-< toList (Vec.map (λ x → ⟦ x ⟧ c) xs) >-
-            ≡⟨ Eq.cong (a V.-<_>-) (Eq.cong toList (Vec.zipWith₁ (λ x → ⟦ x ⟧ c) xs ys)) ⟨
-              a V.-< toList (zipWith (λ x y → ⟦ x ⟧ c) xs ys) >-
-            ≡⟨⟩
-              a V.-< toList (zipWith (λ x y → if true then ⟦ x ⟧ c else ⟦ y ⟧ c) xs ys) >-
-            ∎
-
-      {-|
-      A choice between two equal alternatives is no choice.
-      No matter how we configure the choice, the result stays the same.
-      -}
-      choice-idempotency : ∀ {D} {e : 2CC Dimension ∞ A}
-          ---------------------------------
-        → 2CCL Dimension ⊢ D ⟨ e , e ⟩ ≣₁ e
-      choice-idempotency {D} {e} c with c D
-      ... | false = refl
-      ... | true  = refl
-
-      {-|
-      If the left alternative of a choice is semantically equivalent
-      to another expression l′, we can replace the left alternative with l′.
-      -}
-      choice-l-congruence : ∀ {i : Size} {D : Dimension} {l l′ r : 2CC Dimension i A}
-        → 2CCL Dimension ⊢ l ≣₁ l′
-          ---------------------------------------
-        → 2CCL Dimension ⊢ D ⟨ l , r ⟩ ≣₁ D ⟨ l′ , r ⟩
-      choice-l-congruence {D = D} l≣l′ c with c D
-      ... | false = refl
-      ... | true  = l≣l′ c
-
-      {-|
-      If the right alternative of a choice is semantically equivalent
-      to another expression r′, we can replace the right alternative with r′.
-      -}
-      choice-r-congruence : ∀ {i : Size} {D : Dimension} {l r r′ : 2CC Dimension i A}
-        → 2CCL Dimension ⊢ r ≣₁ r′
-          ---------------------------------------
-        → 2CCL Dimension ⊢ D ⟨ l , r ⟩ ≣₁ D ⟨ l , r′ ⟩
-      choice-r-congruence {D = D} r≣r′ c with c D
-      ... | false = r≣r′ c
-      ... | true  = refl
-```
-
-## Utility
-
-```agda
-  open Data.List using (concatMap) renaming (_++_ to _++l_)
-
-  {-|
-  Recursively, collect all dimensions used in a binary CC expression
-  -}
-  dims : ∀ {i : Size} {A : 𝔸} → 2CC Dimension i A → List Dimension
-  dims (_ -< es >-)  = concatMap dims es
-  dims (D ⟨ l , r ⟩) = D ∷ (dims l ++l dims r)
-```
-
-## Show
-
-```agda
-  open import Data.String as String using (String; _++_; intersperse)
-  module Pretty (show-D : Dimension → String) where
-    open import Vatras.Show.Lines
-
-    show : ∀ {i} → 2CC Dimension i (String , String._≟_) → String
-    show (a -< [] >-) = a
-    show (a -< es@(_ ∷ _) >-) = a ++ "-<" ++ (intersperse ", " (mapl show es)) ++ ">-"
-    show (D ⟨ l , r ⟩) = show-D D ++ "⟨" ++ (show l) ++ ", " ++ (show r) ++ "⟩"
-
-    pretty : ∀ {i : Size} → 2CC Dimension i (String , String._≟_) → Lines
-    pretty (a -< [] >-) = > a
-    pretty (a -< es@(_ ∷ _) >-) = do
-      > a ++ "-<"
-      indent 2 do
-        intersperseCommas (mapl pretty es)
-      > ">-"
-    pretty (D ⟨ l , r ⟩) = do
-      > show-D D ++ "⟨"
-      indent 2 do
-        appendToLastLine "," (pretty l)
-        pretty r
-      > "⟩"
+2CCL : ∀ {i : Size} → VariabilityLanguage (Rose ∞)
+2CCL {i} = ⟪ 2CC i , Configuration , ⟦_⟧ ⟫
 ```

src/Vatras/Lang/2CC/Properties.agda

@@ -0,0 +1,114 @@
+open import Vatras.Framework.Definitions using (𝔽; 𝔸; atoms; 𝔼; ℂ)
+module Vatras.Lang.2CC.Properties {Dimension : 𝔽} {A : 𝔸} where
+
+{-
+In the following, we prove some interesting properties about binary choice calculus,
+known from the respective papers.
+-}
+
+open import Size using (Size; ∞)
+open import Data.Bool using (Bool; true; false; if_then_else_)
+import Data.List as List
+open import Data.Nat using (ℕ)
+open import Data.Vec as Vec using (Vec; toList; zipWith)
+import Data.Vec.Properties as Vec
+open import Relation.Binary.PropositionalEquality as Eq using (_≡_; refl)
+
+import Vatras.Util.Vec as Vec
+open import Vatras.Framework.Variants as V using (Rose)
+open import Vatras.Framework.Relation.Expression (Rose ∞) using (_⊢_≣₁_)
+open import Vatras.Lang.2CC Dimension using (2CC; _-<_>-; _⟨_,_⟩; 2CCL; ⟦_⟧)
+
+{-|
+Given a choice between two artifacts with the same atom 'a',
+we can factor out this atom 'a' outside of the choice because no matter
+how we configure the choice, the resulting expression will always have 'a'
+at the top.
+-}
+choice-factoring : ∀ {i} {D : Dimension} {a : atoms A} {n : ℕ}
+  → (xs ys : Vec (2CC i A) n)
+    ------------------------------------------------
+  → 2CCL ⊢
+        D ⟨ a -< toList xs >- , a -< toList ys >- ⟩
+      ≣₁ a -< toList (zipWith (D ⟨_,_⟩) xs ys) >-
+choice-factoring {i} {D} {a} {n} xs ys c =
+    ⟦ D ⟨ a -< toList xs >- , a -< toList ys >- ⟩ ⟧ c
+  ≡⟨⟩
+    (if c D then ⟦ a -< toList xs >- ⟧ c else ⟦ a -< toList ys >- ⟧ c)
+  ≡⟨ lemma (c D) ⟩
+    a V.-< toList (zipWith (λ x y → if c D then ⟦ x ⟧ c else ⟦ y ⟧ c) xs ys) >-
+  ≡⟨⟩
+    a V.-< toList (zipWith (λ x y → ⟦ D ⟨ x , y ⟩ ⟧ c) xs ys) >-
+  ≡⟨ Eq.cong (a V.-<_>-) (Eq.cong toList (Vec.map-zipWith (λ e → ⟦ e ⟧ c) (D ⟨_,_⟩) xs ys)) ⟨
+    a V.-< toList (Vec.map (λ e → ⟦ e ⟧ c) (zipWith (D ⟨_,_⟩) xs ys)) >-
+  ≡⟨ Eq.cong (a V.-<_>-) (Vec.toList-map (λ e → ⟦ e ⟧ c) (zipWith (D ⟨_,_⟩) xs ys)) ⟩
+    a V.-< List.map (λ e → ⟦ e ⟧ c) (toList (zipWith (D ⟨_,_⟩) xs ys)) >-
+  ≡⟨⟩
+    ⟦ a -< toList (zipWith (D ⟨_,_⟩) xs ys) >- ⟧ c
+  ∎
+  where
+    open Eq.≡-Reasoning
+    lemma : (b : Bool) →
+        (if b then ⟦ a -< toList xs >- ⟧ c else ⟦ a -< toList ys >- ⟧ c)
+      ≡ a V.-< toList (zipWith (λ x y → if b then ⟦ x ⟧ c else ⟦ y ⟧ c) xs ys) >-
+    lemma false =
+        (if false then ⟦ a -< toList xs >- ⟧ c else ⟦ a -< toList ys >- ⟧ c)
+      ≡⟨⟩
+        ⟦ a -< toList ys >- ⟧ c
+      ≡⟨⟩
+        a V.-< List.map (λ e → ⟦ e ⟧ c) (toList ys) >-
+      ≡⟨ Eq.cong (a V.-<_>-) (Vec.toList-map (λ e → ⟦ e ⟧ c) ys) ⟨
+        a V.-< toList (Vec.map (λ y → ⟦ y ⟧ c) ys) >-
+      ≡⟨ Eq.cong (a V.-<_>-) (Eq.cong toList (Vec.zipWith₂ (λ y → ⟦ y ⟧ c) xs ys)) ⟨
+        a V.-< toList (zipWith (λ x y → ⟦ y ⟧ c) xs ys) >-
+      ≡⟨⟩
+        a V.-< toList (zipWith (λ x y → if false then ⟦ x ⟧ c else ⟦ y ⟧ c) xs ys) >-
+      ∎
+    lemma true =
+        (if true then ⟦ a -< toList xs >- ⟧ c else ⟦ a -< toList ys >- ⟧ c)
+      ≡⟨⟩
+        ⟦ a -< toList xs >- ⟧ c
+      ≡⟨⟩
+        a V.-< List.map (λ e → ⟦ e ⟧ c) (toList xs) >-
+      ≡⟨ Eq.cong (a V.-<_>-) (Vec.toList-map (λ e → ⟦ e ⟧ c) xs) ⟨
+        a V.-< toList (Vec.map (λ x → ⟦ x ⟧ c) xs) >-
+      ≡⟨ Eq.cong (a V.-<_>-) (Eq.cong toList (Vec.zipWith₁ (λ x → ⟦ x ⟧ c) xs ys)) ⟨
+        a V.-< toList (zipWith (λ x y → ⟦ x ⟧ c) xs ys) >-
+      ≡⟨⟩
+        a V.-< toList (zipWith (λ x y → if true then ⟦ x ⟧ c else ⟦ y ⟧ c) xs ys) >-
+      ∎
+
+{-|
+A choice between two equal alternatives is no choice.
+No matter how we configure the choice, the result stays the same.
+-}
+choice-idempotency : ∀ {D} {e : 2CC ∞ A}
+    ---------------------------------
+  → 2CCL ⊢ D ⟨ e , e ⟩ ≣₁ e
+choice-idempotency {D} {e} c with c D
+... | false = refl
+... | true  = refl
+
+{-|
+If the left alternative of a choice is semantically equivalent
+to another expression l′, we can replace the left alternative with l′.
+-}
+choice-l-congruence : ∀ {i : Size} {D : Dimension} {l l′ r : 2CC i A}
+  → 2CCL ⊢ l ≣₁ l′
+    ---------------------------------------
+  → 2CCL ⊢ D ⟨ l , r ⟩ ≣₁ D ⟨ l′ , r ⟩
+choice-l-congruence {D = D} l≣l′ c with c D
+... | false = refl
+... | true  = l≣l′ c
+
+{-|
+If the right alternative of a choice is semantically equivalent
+to another expression r′, we can replace the right alternative with r′.
+-}
+choice-r-congruence : ∀ {i : Size} {D : Dimension} {l r r′ : 2CC i A}
+  → 2CCL ⊢ r ≣₁ r′
+    ---------------------------------------
+  → 2CCL ⊢ D ⟨ l , r ⟩ ≣₁ D ⟨ l , r′ ⟩
+choice-r-congruence {D = D} r≣r′ c with c D
+... | false = r≣r′ c
+... | true  = refl

src/Vatras/Lang/2CC/Show.agda

@@ -0,0 +1,29 @@
+open import Vatras.Framework.Definitions
+open import Data.String as String using (String; _++_)
+module Vatras.Lang.2CC.Show {Dimension : 𝔽} (show-D : Dimension → String) where
+
+open import Size using (Size)
+open import Data.Product using (_,_)
+open import Data.List as List using ([]; _∷_)
+
+open import Vatras.Show.Lines
+open import Vatras.Lang.2CC Dimension using (2CC; _⟨_,_⟩; _-<_>-)
+
+show : ∀ {i} → 2CC i (String , String._≟_) → String
+show (a -< [] >-) = a
+show (a -< es@(_ ∷ _) >-) = a ++ "-<" ++ (String.intersperse ", " (List.map show es)) ++ ">-"
+show (D ⟨ l , r ⟩) = show-D D ++ "⟨" ++ (show l) ++ ", " ++ (show r) ++ "⟩"
+
+pretty : ∀ {i : Size} → 2CC i (String , String._≟_) → Lines
+pretty (a -< [] >-) = > a
+pretty (a -< es@(_ ∷ _) >-) = do
+  > a ++ "-<"
+  indent 2 do
+    intersperseCommas (List.map pretty es)
+  > ">-"
+pretty (D ⟨ l , r ⟩) = do
+  > show-D D ++ "⟨"
+  indent 2 do
+    appendToLastLine "," (pretty l)
+    pretty r
+  > "⟩"