refactor: Split Constructions module (#4656)

for better build paralleization and less rebuilding when editing one of
these files.

src/Lean/Elab/ComputedFields.lean

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Gabriel Ebner
 -/
 prelude
-import Lean.Meta.Constructions
+import Lean.Meta.Constructions.CasesOn
 import Lean.Compiler.ImplementedByAttr
 import Lean.Elab.PreDefinition.WF.Eqns
 

src/Lean/Meta/Constructions.lean

@@ -4,135 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Leonardo de Moura
 -/
 prelude
-import Lean.AuxRecursor
-import Lean.AddDecl
-import Lean.Meta.AppBuilder
-import Lean.Meta.CompletionName
+import Lean.Meta.Constructions.CasesOn
+import Lean.Meta.Constructions.NoConfusion
 import Lean.Meta.Constructions.RecOn
 import Lean.Meta.Constructions.BRecOn
-
-namespace Lean
-
-@[extern "lean_mk_cases_on"] opaque mkCasesOnImp (env : Environment) (declName : @& Name) : Except KernelException Declaration
-@[extern "lean_mk_no_confusion_type"] opaque mkNoConfusionTypeCoreImp (env : Environment) (declName : @& Name) : Except KernelException Declaration
-@[extern "lean_mk_no_confusion"] opaque mkNoConfusionCoreImp (env : Environment) (declName : @& Name) : Except KernelException Declaration
-
-open Meta
-
-def mkCasesOn (declName : Name) : MetaM Unit := do
-  let name := mkCasesOnName declName
-  let decl ← ofExceptKernelException (mkCasesOnImp (← getEnv) declName)
-  addDecl decl
-  setReducibleAttribute name
-  modifyEnv fun env => markAuxRecursor env name
-  modifyEnv fun env => addProtected env name
-
-def mkNoConfusionCore (declName : Name) : MetaM Unit := do
-  -- Do not do anything unless can_elim_to_type. TODO: Extract to util
-  let .inductInfo indVal ← getConstInfo declName | return
-  let recInfo ← getConstInfo (mkRecName declName)
-  unless recInfo.levelParams.length > indVal.levelParams.length do return
-
-  let name := Name.mkStr declName "noConfusionType"
-  let decl ← ofExceptKernelException (mkNoConfusionTypeCoreImp (← getEnv) declName)
-  addDecl decl
-  setReducibleAttribute name
-  modifyEnv fun env => addToCompletionBlackList env name
-  modifyEnv fun env => addProtected env name
-
-  let name := Name.mkStr declName "noConfusion"
-  let decl ← ofExceptKernelException (mkNoConfusionCoreImp (← getEnv) declName)
-  addDecl decl
-  setReducibleAttribute name
-  modifyEnv fun env => markNoConfusion env name
-  modifyEnv fun env => addProtected env name
-
-def mkNoConfusionEnum (enumName : Name) : MetaM Unit := do
-  if (← getEnv).contains ``noConfusionEnum then
-    mkToCtorIdx
-    mkNoConfusionType
-    mkNoConfusion
-  else
-    -- `noConfusionEnum` was not defined yet, so we use `mkNoConfusionCore`
-    mkNoConfusionCore enumName
-where
-  mkToCtorIdx : MetaM Unit := do
-    let ConstantInfo.inductInfo info ← getConstInfo enumName | unreachable!
-    let us := info.levelParams.map mkLevelParam
-    let numCtors := info.ctors.length
-    let declName := Name.mkStr enumName "toCtorIdx"
-    let enumType := mkConst enumName us
-    let natType  := mkConst ``Nat
-    let declType ← mkArrow enumType natType
-    let mut minors := #[]
-    for i in [:numCtors] do
-      minors := minors.push <| mkNatLit i
-    withLocalDeclD `x enumType fun x => do
-      let motive ← mkLambdaFVars #[x] natType
-      let declValue ← mkLambdaFVars #[x] <| mkAppN (mkApp2 (mkConst (mkCasesOnName enumName) (levelOne::us)) motive x) minors
-      addAndCompile <| Declaration.defnDecl {
-        name        := declName
-        levelParams := info.levelParams
-        type        := declType
-        value       := declValue
-        safety      := DefinitionSafety.safe
-        hints       := ReducibilityHints.abbrev
-      }
-      setReducibleAttribute declName
-
-  mkNoConfusionType : MetaM Unit := do
-    let ConstantInfo.inductInfo info ← getConstInfo enumName | unreachable!
-    let us := info.levelParams.map mkLevelParam
-    let v ← mkFreshUserName `v
-    let enumType := mkConst enumName us
-    let sortV := mkSort (mkLevelParam v)
-    let toCtorIdx := mkConst (Name.mkStr enumName "toCtorIdx") us
-    withLocalDeclD `P sortV fun P =>
-    withLocalDeclD `x enumType fun x =>
-    withLocalDeclD `y enumType fun y => do
-      let declType  ← mkForallFVars #[P, x, y] sortV
-      let declValue ← mkLambdaFVars #[P, x, y] (← mkAppM ``noConfusionTypeEnum #[toCtorIdx, P, x, y])
-      let declName  := Name.mkStr enumName "noConfusionType"
-      addAndCompile <| Declaration.defnDecl {
-        name        := declName
-        levelParams := v :: info.levelParams
-        type        := declType
-        value       := declValue
-        safety      := DefinitionSafety.safe
-        hints       := ReducibilityHints.abbrev
-      }
-      setReducibleAttribute declName
-
-  mkNoConfusion : MetaM Unit := do
-    let ConstantInfo.inductInfo info ← getConstInfo enumName | unreachable!
-    let us := info.levelParams.map mkLevelParam
-    let v ← mkFreshUserName `v
-    let enumType := mkConst enumName us
-    let sortV := mkSort (mkLevelParam v)
-    let toCtorIdx := mkConst (Name.mkStr enumName "toCtorIdx") us
-    let noConfusionType := mkConst (Name.mkStr enumName "noConfusionType") (mkLevelParam v :: us)
-    withLocalDecl `P BinderInfo.implicit sortV fun P =>
-    withLocalDecl `x BinderInfo.implicit enumType fun x =>
-    withLocalDecl `y BinderInfo.implicit enumType fun y => do
-    withLocalDeclD `h (← mkEq x y) fun h => do
-      let declType  ← mkForallFVars #[P, x, y, h] (mkApp3 noConfusionType P x y)
-      let declValue ← mkLambdaFVars #[P, x, y, h] (← mkAppOptM ``noConfusionEnum #[none, none, none, toCtorIdx, P, x, y, h])
-      let declName  := Name.mkStr enumName "noConfusion"
-      addAndCompile <| Declaration.defnDecl {
-        name        := declName
-        levelParams := v :: info.levelParams
-        type        := declType
-        value       := declValue
-        safety      := DefinitionSafety.safe
-        hints       := ReducibilityHints.abbrev
-      }
-      setReducibleAttribute declName
-      modifyEnv fun env => markNoConfusion env declName
-
-def mkNoConfusion (declName : Name) : MetaM Unit := do
-  if (← isEnumType declName) then
-    mkNoConfusionEnum declName
-  else
-    mkNoConfusionCore declName
-
-end Lean

src/Lean/Meta/Constructions/CasesOn.lean

@@ -0,0 +1,23 @@
+/-
+Copyright (c) 2020 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Leonardo de Moura
+-/
+prelude
+import Lean.AddDecl
+import Lean.Meta.Basic
+
+namespace Lean
+
+@[extern "lean_mk_cases_on"] opaque mkCasesOnImp (env : Environment) (declName : @& Name) : Except KernelException Declaration
+
+open Meta
+
+def mkCasesOn (declName : Name) : MetaM Unit := do
+  let name := mkCasesOnName declName
+  let decl ← ofExceptKernelException (mkCasesOnImp (← getEnv) declName)
+  addDecl decl
+  setReducibleAttribute name
+  modifyEnv fun env => markAuxRecursor env name
+
+end Lean

src/Lean/Meta/Constructions/NoConfusion.lean

@@ -0,0 +1,126 @@
+/-
+Copyright (c) 2020 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Leonardo de Moura
+-/
+prelude
+import Lean.AddDecl
+import Lean.Meta.AppBuilder
+import Lean.Meta.CompletionName
+
+namespace Lean
+
+@[extern "lean_mk_no_confusion_type"] opaque mkNoConfusionTypeCoreImp (env : Environment) (declName : @& Name) : Except KernelException Declaration
+@[extern "lean_mk_no_confusion"] opaque mkNoConfusionCoreImp (env : Environment) (declName : @& Name) : Except KernelException Declaration
+
+open Meta
+
+def mkNoConfusionCore (declName : Name) : MetaM Unit := do
+  -- Do not do anything unless can_elim_to_type. TODO: Extract to util
+  let .inductInfo indVal ← getConstInfo declName | return
+  let recInfo ← getConstInfo (mkRecName declName)
+  unless recInfo.levelParams.length > indVal.levelParams.length do return
+
+  let name := Name.mkStr declName "noConfusionType"
+  let decl ← ofExceptKernelException (mkNoConfusionTypeCoreImp (← getEnv) declName)
+  addDecl decl
+  setReducibleAttribute name
+  modifyEnv fun env => addToCompletionBlackList env name
+  modifyEnv fun env => addProtected env name
+
+  let name := Name.mkStr declName "noConfusion"
+  let decl ← ofExceptKernelException (mkNoConfusionCoreImp (← getEnv) declName)
+  addDecl decl
+  setReducibleAttribute name
+  modifyEnv fun env => markNoConfusion env name
+  modifyEnv fun env => addProtected env name
+
+def mkNoConfusionEnum (enumName : Name) : MetaM Unit := do
+  if (← getEnv).contains ``noConfusionEnum then
+    mkToCtorIdx
+    mkNoConfusionType
+    mkNoConfusion
+  else
+    -- `noConfusionEnum` was not defined yet, so we use `mkNoConfusionCore`
+    mkNoConfusionCore enumName
+where
+  mkToCtorIdx : MetaM Unit := do
+    let ConstantInfo.inductInfo info ← getConstInfo enumName | unreachable!
+    let us := info.levelParams.map mkLevelParam
+    let numCtors := info.ctors.length
+    let declName := Name.mkStr enumName "toCtorIdx"
+    let enumType := mkConst enumName us
+    let natType  := mkConst ``Nat
+    let declType ← mkArrow enumType natType
+    let mut minors := #[]
+    for i in [:numCtors] do
+      minors := minors.push <| mkNatLit i
+    withLocalDeclD `x enumType fun x => do
+      let motive ← mkLambdaFVars #[x] natType
+      let declValue ← mkLambdaFVars #[x] <| mkAppN (mkApp2 (mkConst (mkCasesOnName enumName) (levelOne::us)) motive x) minors
+      addAndCompile <| Declaration.defnDecl {
+        name        := declName
+        levelParams := info.levelParams
+        type        := declType
+        value       := declValue
+        safety      := DefinitionSafety.safe
+        hints       := ReducibilityHints.abbrev
+      }
+      setReducibleAttribute declName
+
+  mkNoConfusionType : MetaM Unit := do
+    let ConstantInfo.inductInfo info ← getConstInfo enumName | unreachable!
+    let us := info.levelParams.map mkLevelParam
+    let v ← mkFreshUserName `v
+    let enumType := mkConst enumName us
+    let sortV := mkSort (mkLevelParam v)
+    let toCtorIdx := mkConst (Name.mkStr enumName "toCtorIdx") us
+    withLocalDeclD `P sortV fun P =>
+    withLocalDeclD `x enumType fun x =>
+    withLocalDeclD `y enumType fun y => do
+      let declType  ← mkForallFVars #[P, x, y] sortV
+      let declValue ← mkLambdaFVars #[P, x, y] (← mkAppM ``noConfusionTypeEnum #[toCtorIdx, P, x, y])
+      let declName  := Name.mkStr enumName "noConfusionType"
+      addAndCompile <| Declaration.defnDecl {
+        name        := declName
+        levelParams := v :: info.levelParams
+        type        := declType
+        value       := declValue
+        safety      := DefinitionSafety.safe
+        hints       := ReducibilityHints.abbrev
+      }
+      setReducibleAttribute declName
+
+  mkNoConfusion : MetaM Unit := do
+    let ConstantInfo.inductInfo info ← getConstInfo enumName | unreachable!
+    let us := info.levelParams.map mkLevelParam
+    let v ← mkFreshUserName `v
+    let enumType := mkConst enumName us
+    let sortV := mkSort (mkLevelParam v)
+    let toCtorIdx := mkConst (Name.mkStr enumName "toCtorIdx") us
+    let noConfusionType := mkConst (Name.mkStr enumName "noConfusionType") (mkLevelParam v :: us)
+    withLocalDecl `P BinderInfo.implicit sortV fun P =>
+    withLocalDecl `x BinderInfo.implicit enumType fun x =>
+    withLocalDecl `y BinderInfo.implicit enumType fun y => do
+    withLocalDeclD `h (← mkEq x y) fun h => do
+      let declType  ← mkForallFVars #[P, x, y, h] (mkApp3 noConfusionType P x y)
+      let declValue ← mkLambdaFVars #[P, x, y, h] (← mkAppOptM ``noConfusionEnum #[none, none, none, toCtorIdx, P, x, y, h])
+      let declName  := Name.mkStr enumName "noConfusion"
+      addAndCompile <| Declaration.defnDecl {
+        name        := declName
+        levelParams := v :: info.levelParams
+        type        := declType
+        value       := declValue
+        safety      := DefinitionSafety.safe
+        hints       := ReducibilityHints.abbrev
+      }
+      setReducibleAttribute declName
+      modifyEnv fun env => markNoConfusion env declName
+
+def mkNoConfusion (declName : Name) : MetaM Unit := do
+  if (← isEnumType declName) then
+    mkNoConfusionEnum declName
+  else
+    mkNoConfusionCore declName
+
+end Lean

src/Lean/Meta/IndPredBelow.lean

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Dany Fabian
 -/
 prelude
-import Lean.Meta.Constructions
+import Lean.Meta.Constructions.CasesOn
 import Lean.Meta.Match.Match
 
 namespace Lean.Meta.IndPredBelow