From 2b7b3700c2768531e26b46a6463ad146eb116b1f Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Thu, 8 Apr 2021 13:42:38 +0200
Subject: [PATCH] ENH: replace keyType with wordRe for matching selectors.

- The keyType is primarily used within dictionary reading, whereas
  wordRe and wordRes are used for selectors in code.
  Unifying on wordRe and wordRes reduces the number matching options.
---
 .../test/PointEdgeWave/Test-PointEdgeWave.C   |   5 +-
 .../mesh/manipulation/subsetMesh/subsetMesh.C |   4 +-
 .../db/dynamicLibrary/codedBase/codedBase.C   |   2 -
 .../meshes/Identifiers/DynamicID/DynamicID.H  | 109 ++++++++++--------
 .../pointBoundaryMesh/pointBoundaryMesh.C     |   6 +-
 .../pointBoundaryMesh/pointBoundaryMesh.H     |   8 +-
 .../polyBoundaryMesh/polyBoundaryMesh.C       |  25 +---
 .../polyBoundaryMesh/polyBoundaryMesh.H       |  15 +--
 .../processorCyclicPolyPatch.C                |   6 +-
 .../meshes/polyMesh/zones/ZoneMesh/ZoneMesh.C |  44 +++----
 .../meshes/polyMesh/zones/ZoneMesh/ZoneMesh.H |  17 ++-
 .../faMesh/faBoundaryMesh/faBoundaryMesh.C    |  23 +---
 .../faMesh/faBoundaryMesh/faBoundaryMesh.H    |  12 +-
 .../porosityModel/porosityModel.C             |   4 +-
 .../porosityModel/porosityModel.H             |   6 +-
 .../fvMesh/fvBoundaryMesh/fvBoundaryMesh.C    |   6 +-
 .../fvMesh/fvBoundaryMesh/fvBoundaryMesh.H    |   6 +-
 .../field/externalCoupled/externalCoupled.C   |   2 +-
 .../externalCoupledTemplates.C                |  26 ++---
 .../ParticleErosion/ParticleErosion.C         |  14 +--
 .../LocalInteraction/patchInteractionData.C   |  36 +-----
 .../LocalInteraction/patchInteractionData.H   |  70 +++++------
 .../patchInteractionDataList.C                |  25 ++--
 .../blockMesh/blockMeshTools/blockMeshTools.C |  48 +++++---
 .../blockMesh/blockMeshTools/blockMeshTools.H |  10 +-
 .../layerParameters/layerParameters.C         |   2 +-
 .../coordinate/systems/coordinateSystems.C    |  76 +++---------
 .../coordinate/systems/coordinateSystems.H    |  15 +--
 28 files changed, 255 insertions(+), 367 deletions(-)

diff --git a/applications/test/PointEdgeWave/Test-PointEdgeWave.C b/applications/test/PointEdgeWave/Test-PointEdgeWave.C
index 4004d2720a..441f2bc1d4 100644
--- a/applications/test/PointEdgeWave/Test-PointEdgeWave.C
+++ b/applications/test/PointEdgeWave/Test-PointEdgeWave.C
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
+    Copyright (C) 2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -49,11 +50,13 @@ int main(int argc, char *argv[])
     #include "createTime.H"
     #include "createPolyMesh.H"
 
+    const wordRes patchSelection(args.getList<wordRe>(1));
+
     const polyBoundaryMesh& pbm = mesh.boundaryMesh();
 
     labelList patchIDs
     (
-        pbm.patchSet(args.getList<wordRe>(1)).sortedToc()
+        pbm.patchSet(patchSelection).sortedToc()
     );
 
     Info<< "Starting walk from patches "
diff --git a/applications/utilities/mesh/manipulation/subsetMesh/subsetMesh.C b/applications/utilities/mesh/manipulation/subsetMesh/subsetMesh.C
index f20f3f4e68..d09c36f7a4 100644
--- a/applications/utilities/mesh/manipulation/subsetMesh/subsetMesh.C
+++ b/applications/utilities/mesh/manipulation/subsetMesh/subsetMesh.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2016-2020 OpenCFD Ltd.
+    Copyright (C) 2016-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -495,7 +495,7 @@ int main(int argc, char *argv[])
     wordRes zoneNames;
     if (useCellZone)
     {
-        List<wordRe> selectionNames = args.getList<wordRe>(1);
+        wordRes selectionNames(args.getList<wordRe>(1));
         zoneNames.transfer(selectionNames);
 
         Info<< "Using cellZone " << flatOutput(zoneNames) << nl << endl;
diff --git a/src/OpenFOAM/db/dynamicLibrary/codedBase/codedBase.C b/src/OpenFOAM/db/dynamicLibrary/codedBase/codedBase.C
index 7d9fbbc721..5cc0775529 100644
--- a/src/OpenFOAM/db/dynamicLibrary/codedBase/codedBase.C
+++ b/src/OpenFOAM/db/dynamicLibrary/codedBase/codedBase.C
@@ -59,11 +59,9 @@ static inline void writeEntryIfPresent
 )
 {
     const entry* eptr = dict.findEntry(key, keyType::LITERAL);
-
     if (eptr)
     {
         const tokenList& toks = eptr->stream();
-
         if (!toks.empty())
         {
             os.writeEntry(key, toks[0]);
diff --git a/src/OpenFOAM/meshes/Identifiers/DynamicID/DynamicID.H b/src/OpenFOAM/meshes/Identifiers/DynamicID/DynamicID.H
index 8ddb596f6d..184b6fab2e 100644
--- a/src/OpenFOAM/meshes/Identifiers/DynamicID/DynamicID.H
+++ b/src/OpenFOAM/meshes/Identifiers/DynamicID/DynamicID.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
-    Copyright (C) 2018 OpenCFD Ltd.
+    Copyright (C) 2018-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -39,7 +39,7 @@ Description
 #ifndef DynamicID_H
 #define DynamicID_H
 
-#include "keyType.H"
+#include "wordRe.H"
 #include "labelList.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
@@ -47,11 +47,6 @@ Description
 namespace Foam
 {
 
-// Forward declarations
-template<class> class DynamicID;
-template<class ObjectType>
-Ostream& operator<<(Ostream&, const DynamicID<ObjectType>&);
-
 /*---------------------------------------------------------------------------*\
                           Class DynamicID Declaration
 \*---------------------------------------------------------------------------*/
@@ -59,12 +54,12 @@ Ostream& operator<<(Ostream&, const DynamicID<ObjectType>&);
 template<class ObjectType>
 class DynamicID
 {
-    // Private data
+    // Private Data
 
-        //- Zone name
-        keyType key_;
+        //- Selector name
+        wordRe key_;
 
-        //- Zone indices
+        //- Selection indices
         labelList indices_;
 
 
@@ -72,18 +67,36 @@ public:
 
     // Constructors
 
-        //- Construct from name
-        DynamicID(const keyType& key, const ObjectType& obj)
+        //- Construct from selector name and object
+        DynamicID(const wordRe& key, const ObjectType& obj)
         :
             key_(key),
             indices_(obj.indices(key_))
         {}
 
-        //- Construct from Istream
+        //- Construct from selector name and object
+        DynamicID(wordRe&& key, const ObjectType& obj)
+        :
+            key_(std::move(key)),
+            indices_(obj.indices(key_))
+        {}
+
+        //- Construct from selector name and object
+        DynamicID(const word& key, const ObjectType& obj)
+        :
+            DynamicID(wordRe(key), obj)
+        {}
+
+        //- Construct from selector name and object
+        DynamicID(const keyType& key, const ObjectType& obj)
+        :
+            DynamicID(wordRe(key), obj)
+        {}
+
+        //- Construct from Istream and object
         DynamicID(Istream& is, const ObjectType& obj)
         :
-            key_(is),
-            indices_(obj.indices(key_))
+            DynamicID(wordRe(is), obj)
         {}
 
 
@@ -93,56 +106,50 @@ public:
 
     // Member Functions
 
-        // Access
+    // Access
 
-            //- Return name
-            const keyType& name() const
-            {
-                return key_;
-            }
+        //- The selector name
+        const wordRe& name() const noexcept
+        {
+            return key_;
+        }
 
-            //- Return indices of matching zones
-            const labelList& indices() const
-            {
-                return indices_;
-            }
+        //- The indices of matching items
+        const labelList& indices() const noexcept
+        {
+            return indices_;
+        }
 
-            //- Return index of first matching zone
-            label index() const
-            {
-                return indices_.empty() ? -1 : indices_.first();
-            }
+        //- The index of the first matching items, -1 if no matches
+        label index() const
+        {
+            return indices_.empty() ? -1 : indices_.first();
+        }
 
-            //- Has the zone been found
-            bool active() const
-            {
-                return !indices_.empty();
-            }
+        //- Has the zone been found
+        bool active() const noexcept
+        {
+            return !indices_.empty();
+        }
 
 
-        // Edit
+    // Edit
 
-            //- Update
-            void update(const ObjectType& obj)
-            {
-                indices_ = obj.indices(key_);
-            }
-
-
-    // IOstream Operators
-
-        friend Ostream& operator<< <ObjectType>
-        (Ostream&, const DynamicID<ObjectType>&);
+        //- Update
+        void update(const ObjectType& obj)
+        {
+            indices_ = obj.indices(key_);
+        }
 };
 
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 template<class ObjectType>
-Ostream& operator<<(Ostream& os, const DynamicID<ObjectType>& dynId)
+Ostream& operator<<(Ostream& os, const DynamicID<ObjectType>& obj)
 {
     os  << token::BEGIN_LIST
-        << dynId.name() << token::SPACE << dynId.index()
+        << obj.name() << token::SPACE << obj.index()
         << token::END_LIST;
 
     os.check(FUNCTION_NAME);
diff --git a/src/OpenFOAM/meshes/pointMesh/pointBoundaryMesh/pointBoundaryMesh.C b/src/OpenFOAM/meshes/pointMesh/pointBoundaryMesh/pointBoundaryMesh.C
index f8dff17d4c..2fee220290 100644
--- a/src/OpenFOAM/meshes/pointMesh/pointBoundaryMesh/pointBoundaryMesh.C
+++ b/src/OpenFOAM/meshes/pointMesh/pointBoundaryMesh/pointBoundaryMesh.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
-    Copyright (C) 2018 OpenCFD Ltd.
+    Copyright (C) 2018-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -63,11 +63,11 @@ Foam::pointBoundaryMesh::pointBoundaryMesh
 
 Foam::labelList Foam::pointBoundaryMesh::indices
 (
-    const keyType& key,
+    const wordRe& matcher,
     const bool useGroups
 ) const
 {
-    return mesh()().boundaryMesh().indices(key, useGroups);
+    return mesh()().boundaryMesh().indices(matcher, useGroups);
 }
 
 
diff --git a/src/OpenFOAM/meshes/pointMesh/pointBoundaryMesh/pointBoundaryMesh.H b/src/OpenFOAM/meshes/pointMesh/pointBoundaryMesh/pointBoundaryMesh.H
index a7a852ae09..d6a470afcc 100644
--- a/src/OpenFOAM/meshes/pointMesh/pointBoundaryMesh/pointBoundaryMesh.H
+++ b/src/OpenFOAM/meshes/pointMesh/pointBoundaryMesh/pointBoundaryMesh.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2013 OpenFOAM Foundation
-    Copyright (C) 2018-2020 OpenCFD Ltd.
+    Copyright (C) 2018-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -94,14 +94,14 @@ public:
     // Member Functions
 
         //- Return the mesh reference
-        const pointMesh& mesh() const
+        const pointMesh& mesh() const noexcept
         {
             return mesh_;
         }
 
         //- Find patch indices given a name
         //  A no-op (returns empty list) for an empty key
-        labelList indices(const keyType& key, const bool useGroups) const;
+        labelList indices(const wordRe& matcher, const bool useGroups) const;
 
         //- Find patch index given a name
         //  A no-op (returns -1) for an empty patchName
@@ -118,7 +118,7 @@ public:
 
         //- Identical to the indices() method (AUG-2018)
         FOAM_DEPRECATED_FOR(2018-08, "indices() method")
-        labelList findIndices(const keyType& key, const bool useGroups) const
+        labelList findIndices(const wordRe& key, bool useGroups) const
         {
             return indices(key, useGroups);
         }
diff --git a/src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.C b/src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.C
index 001b19df7b..341c984bdc 100644
--- a/src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.C
+++ b/src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.C
@@ -604,20 +604,19 @@ Foam::labelRange Foam::polyBoundaryMesh::range(const label patchi) const
 
 Foam::labelList Foam::polyBoundaryMesh::indices
 (
-    const keyType& key,
+    const wordRe& matcher,
     const bool useGroups
 ) const
 {
-    if (key.empty())
+    if (matcher.empty())
     {
         return labelList();
     }
 
     DynamicList<label> patchIndices;
 
-    if (key.isPattern())
+    if (matcher.isPattern())
     {
-        const regExp matcher(key);
         patchIndices = PtrListOps::findMatching(*this, matcher);
 
         // Only examine patch groups if requested and when they exist.
@@ -648,7 +647,6 @@ Foam::labelList Foam::polyBoundaryMesh::indices
         // Literal string.
         // Special version of above for reduced memory footprint
 
-        const word& matcher = key;
         const label patchId = PtrListOps::firstMatching(*this, matcher);
 
         if (patchId >= 0)
@@ -659,7 +657,7 @@ Foam::labelList Foam::polyBoundaryMesh::indices
         // Only examine patch groups if requested and when they exist.
         if (useGroups && !groupPatchIDs().empty())
         {
-            const auto iter = groupPatchIDs().cfind(key);
+            const auto iter = groupPatchIDs().cfind(matcher);
 
             if (iter.found())
             {
@@ -676,24 +674,13 @@ Foam::labelList Foam::polyBoundaryMesh::indices
 }
 
 
-Foam::label Foam::polyBoundaryMesh::findIndex(const keyType& key) const
+Foam::label Foam::polyBoundaryMesh::findIndex(const wordRe& key) const
 {
     if (key.empty())
     {
         return -1;
     }
-    else if (key.isPattern())
-    {
-        // Find as regex
-        const regExp matcher(key);
-        return PtrListOps::firstMatching(*this, matcher);
-    }
-    else
-    {
-        // Find as literal string
-        const word& matcher = key;
-        return PtrListOps::firstMatching(*this, matcher);
-    }
+    return PtrListOps::firstMatching(*this, key);
 }
 
 
diff --git a/src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.H b/src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.H
index c3d0b0f4b5..8f90c0f8f5 100644
--- a/src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.H
+++ b/src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.H
@@ -132,6 +132,7 @@ public:
     //- Destructor
     ~polyBoundaryMesh() = default;
 
+
         //- Clear geometry at this level and at patches
         void clearGeom();
 
@@ -142,7 +143,7 @@ public:
     // Member Functions
 
         //- Return the mesh reference
-        const polyMesh& mesh() const
+        const polyMesh& mesh() const noexcept
         {
             return mesh_;
         }
@@ -200,14 +201,14 @@ public:
         //  A no-op (returns empty list) for an empty key
         labelList indices
         (
-            const keyType& key,
+            const wordRe& matcher,
             const bool useGroups = true
         ) const;
 
 
         //- Return patch index for the first match, return -1 if not found
         //  A no-op (returns -1) for an empty key
-        label findIndex(const keyType& key) const;
+        label findIndex(const wordRe& key) const;
 
         //- Find patch index given a name, return -1 if not found
         //  A no-op (returns -1) for an empty patchName
@@ -296,7 +297,7 @@ public:
         polyPatch& operator[](const word& patchName);
 
 
-    // Ostream operator
+    // Ostream Operator
 
         friend Ostream& operator<<(Ostream& os, const polyBoundaryMesh& pbm);
 
@@ -305,11 +306,7 @@ public:
 
         //- Identical to the indices() method (AUG-2018)
         FOAM_DEPRECATED_FOR(2018-08, "indices() method")
-        labelList findIndices
-        (
-            const keyType& key,
-            const bool useGroups = true
-        ) const
+        labelList findIndices(const wordRe& key, bool useGroups=true) const
         {
             return this->indices(key, useGroups);
         }
diff --git a/src/OpenFOAM/meshes/polyMesh/polyPatches/constraint/processorCyclic/processorCyclicPolyPatch.C b/src/OpenFOAM/meshes/polyMesh/polyPatches/constraint/processorCyclic/processorCyclicPolyPatch.C
index 36645c38bb..975b078f18 100644
--- a/src/OpenFOAM/meshes/polyMesh/polyPatches/constraint/processorCyclic/processorCyclicPolyPatch.C
+++ b/src/OpenFOAM/meshes/polyMesh/polyPatches/constraint/processorCyclic/processorCyclicPolyPatch.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2019-2020 OpenCFD Ltd.
+    Copyright (C) 2019-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -181,10 +181,10 @@ Foam::labelList Foam::processorCyclicPolyPatch::patchIDs
 {
     return bm.indices
     (
-        keyType
+        wordRe
         (
             "procBoundary.*to.*through" + cyclicPolyPatchName,
-            keyType::REGEX
+            wordRe::REGEX
         )
     );
 }
diff --git a/src/OpenFOAM/meshes/polyMesh/zones/ZoneMesh/ZoneMesh.C b/src/OpenFOAM/meshes/polyMesh/zones/ZoneMesh/ZoneMesh.C
index c2386312c5..2084d56782 100644
--- a/src/OpenFOAM/meshes/polyMesh/zones/ZoneMesh/ZoneMesh.C
+++ b/src/OpenFOAM/meshes/polyMesh/zones/ZoneMesh/ZoneMesh.C
@@ -311,25 +311,14 @@ const
 template<class ZoneType, class MeshType>
 Foam::labelList Foam::ZoneMesh<ZoneType, MeshType>::indices
 (
-    const keyType& key
+    const wordRe& matcher
 ) const
 {
-    if (key.empty())
+    if (matcher.empty())
     {
         return labelList();
     }
-    else if (key.isPattern())
-    {
-        // Match as regex
-        const regExp matcher(key);
-        return PtrListOps::findMatching(*this, matcher);
-    }
-    else
-    {
-        // Compare as literal string
-        const word& matcher = key;
-        return PtrListOps::findMatching(*this, matcher);
-    }
+    return PtrListOps::findMatching(*this, matcher);
 }
 
 
@@ -350,25 +339,14 @@ Foam::labelList Foam::ZoneMesh<ZoneType, MeshType>::indices
 template<class ZoneType, class MeshType>
 Foam::label Foam::ZoneMesh<ZoneType, MeshType>::findIndex
 (
-    const keyType& key
+    const wordRe& key
 ) const
 {
     if (key.empty())
     {
         return -1;
     }
-    else if (key.isPattern())
-    {
-        // Find as regex
-        const regExp matcher(key);
-        return PtrListOps::firstMatching(*this, matcher);
-    }
-    else
-    {
-        // Find as literal string
-        const word& matcher = key;
-        return PtrListOps::firstMatching(*this, matcher);
-    }
+    return PtrListOps::firstMatching(*this, key);
 }
 
 
@@ -378,7 +356,11 @@ Foam::label Foam::ZoneMesh<ZoneType, MeshType>::findIndex
     const wordRes& matcher
 ) const
 {
-    return (matcher.empty() ? -1 : PtrListOps::firstMatching(*this, matcher));
+    if (matcher.empty())
+    {
+        return -1;
+    }
+    return PtrListOps::firstMatching(*this, matcher);
 }
 
 
@@ -495,11 +477,11 @@ Foam::bitSet Foam::ZoneMesh<ZoneType, MeshType>::selection
 template<class ZoneType, class MeshType>
 Foam::bitSet Foam::ZoneMesh<ZoneType, MeshType>::selection
 (
-    const keyType& key
+    const wordRe& matcher
 ) const
 {
-    // key.empty() is handled by indices()
-    return this->selection(this->indices(key));
+    // matcher.empty() is handled by indices()
+    return this->selection(this->indices(matcher));
 }
 
 
diff --git a/src/OpenFOAM/meshes/polyMesh/zones/ZoneMesh/ZoneMesh.H b/src/OpenFOAM/meshes/polyMesh/zones/ZoneMesh/ZoneMesh.H
index a6dffca158..e4c0960a1d 100644
--- a/src/OpenFOAM/meshes/polyMesh/zones/ZoneMesh/ZoneMesh.H
+++ b/src/OpenFOAM/meshes/polyMesh/zones/ZoneMesh/ZoneMesh.H
@@ -38,10 +38,10 @@ SourceFiles
 #ifndef ZoneMesh_H
 #define ZoneMesh_H
 
-#include "List.H"
 #include "regIOobject.H"
 #include "pointField.H"
 #include "Map.H"
+#include "PtrList.H"
 #include "bitSet.H"
 #include "wordRes.H"
 
@@ -51,7 +51,6 @@ namespace Foam
 {
 
 // Forward Declarations
-
 template<class ZoneType, class MeshType> class ZoneMesh;
 
 template<class ZoneType, class MeshType>
@@ -131,7 +130,7 @@ public:
     // Member Functions
 
         //- Return the mesh reference
-        const MeshType& mesh() const
+        const MeshType& mesh() const noexcept
         {
             return mesh_;
         }
@@ -167,8 +166,8 @@ public:
 
 
         //- Return zone indices for all matches
-        //  A no-op (returns empty list) for an empty key
-        labelList indices(const keyType& key) const;
+        //  A no-op (returns empty list) for an empty matcher
+        labelList indices(const wordRe& matcher) const;
 
         //- Return zone indices for all matches
         //  A no-op (returns empty list) for an empty matcher
@@ -176,7 +175,7 @@ public:
 
         //- Zone index for the first match, return -1 if not found
         //  A no-op (returns -1) for an empty key
-        label findIndex(const keyType& key) const;
+        label findIndex(const wordRe& key) const;
 
         //- Zone index for the first match, return -1 if not found
         //  A no-op (returns -1) for an empty matcher
@@ -205,8 +204,8 @@ public:
         //- specification as a bitSet.
         //  The bitSet is empty (zero-size) if there are no elements matched
         //  anywhere.
-        //  A no-op (returns empty bitSet) for an empty key
-        bitSet selection(const keyType& key) const;
+        //  A no-op (returns empty bitSet) for an empty matcher
+        bitSet selection(const wordRe& matcher) const;
 
         //- Return all elements (cells, faces, points) that match the zone
         //- specification as a bitSet.
@@ -288,7 +287,7 @@ public:
 
         //- Identical to the indices() method (AUG-2018)
         FOAM_DEPRECATED_FOR(2018-08, "indices() method")
-        labelList findIndices(const keyType& key) const
+        labelList findIndices(const wordRes& key) const
         {
             return indices(key);
         }
diff --git a/src/finiteArea/faMesh/faBoundaryMesh/faBoundaryMesh.C b/src/finiteArea/faMesh/faBoundaryMesh/faBoundaryMesh.C
index 3a42e98ce8..b436ecf996 100644
--- a/src/finiteArea/faMesh/faBoundaryMesh/faBoundaryMesh.C
+++ b/src/finiteArea/faMesh/faBoundaryMesh/faBoundaryMesh.C
@@ -157,18 +157,17 @@ Foam::wordList Foam::faBoundaryMesh::types() const
 
 Foam::labelList Foam::faBoundaryMesh::indices
 (
-    const keyType& key,
+    const wordRe& matcher,
     const bool useGroups  // ignored
 ) const
 {
-    if (key.empty())
+    if (matcher.empty())
     {
         return labelList();
     }
 
-    if (key.isPattern())
+    if (matcher.isPattern())
     {
-        const regExp matcher(key);
         return PtrListOps::findMatching(*this, matcher);
     }
     else
@@ -176,7 +175,6 @@ Foam::labelList Foam::faBoundaryMesh::indices
         // Literal string.
         // Special version of above for reduced memory footprint
 
-        const word& matcher = key;
         const label patchId = PtrListOps::firstMatching(*this, matcher);
 
         if (patchId >= 0)
@@ -189,24 +187,13 @@ Foam::labelList Foam::faBoundaryMesh::indices
 }
 
 
-Foam::label Foam::faBoundaryMesh::findIndex(const keyType& key) const
+Foam::label Foam::faBoundaryMesh::findIndex(const wordRe& key) const
 {
     if (key.empty())
     {
         return -1;
     }
-    else if (key.isPattern())
-    {
-        // Find as regex
-        const regExp matcher(key);
-        return PtrListOps::firstMatching(*this, matcher);
-    }
-    else
-    {
-        // Find as literal string
-        const word& matcher = key;
-        return PtrListOps::firstMatching(*this, matcher);
-    }
+    return PtrListOps::firstMatching(*this, key);
 }
 
 
diff --git a/src/finiteArea/faMesh/faBoundaryMesh/faBoundaryMesh.H b/src/finiteArea/faMesh/faBoundaryMesh/faBoundaryMesh.H
index 579fdbbbcb..4c2c69ead5 100644
--- a/src/finiteArea/faMesh/faBoundaryMesh/faBoundaryMesh.H
+++ b/src/finiteArea/faMesh/faBoundaryMesh/faBoundaryMesh.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 Wikki Ltd
-    Copyright (C) 2018-2020 OpenCFD Ltd.
+    Copyright (C) 2018-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -135,13 +135,13 @@ public:
             //  \note Matching patchGroups currently not supported
             labelList indices
             (
-                const keyType& key,
+                const wordRe& matcher,
                 const bool useGroups = false  /* ignored */
             ) const;
 
             //- Return patch index for the first match, return -1 if not found
             //  A no-op (returns -1) for an empty key
-            label findIndex(const keyType& key) const;
+            label findIndex(const wordRe& key) const;
 
             //- Find patch index given a name, return -1 if not found
             //  A no-op (returns -1) for an empty name
@@ -175,11 +175,7 @@ public:
 
         //- Identical to the indices() method (AUG-2018)
         FOAM_DEPRECATED_FOR(2018-08, "indices() method")
-        labelList findIndices
-        (
-            const keyType& key,
-            const bool useGroups = false
-        ) const
+        labelList findIndices(const wordRe& key, bool useGroups=false) const
         {
             return indices(key, useGroups);
         }
diff --git a/src/finiteVolume/cfdTools/general/porosityModel/porosityModel/porosityModel.C b/src/finiteVolume/cfdTools/general/porosityModel/porosityModel/porosityModel.C
index 716e8aaa7f..e189d099e6 100644
--- a/src/finiteVolume/cfdTools/general/porosityModel/porosityModel/porosityModel.C
+++ b/src/finiteVolume/cfdTools/general/porosityModel/porosityModel/porosityModel.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2012-2017 OpenFOAM Foundation
-    Copyright (C) 2016 OpenCFD Ltd.
+    Copyright (C) 2016-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -99,7 +99,7 @@ Foam::porosityModel::porosityModel
         coordinateSystem::New(mesh, coeffs_, coordinateSystem::typeName_())
     )
 {
-    if (zoneName_ == word::null)
+    if (zoneName_.empty())
     {
         dict.readIfPresent("active", active_);
         dict_.readEntry("cellZone", zoneName_);
diff --git a/src/finiteVolume/cfdTools/general/porosityModel/porosityModel/porosityModel.H b/src/finiteVolume/cfdTools/general/porosityModel/porosityModel/porosityModel.H
index d5b2a64864..229bbfc2c5 100644
--- a/src/finiteVolume/cfdTools/general/porosityModel/porosityModel/porosityModel.H
+++ b/src/finiteVolume/cfdTools/general/porosityModel/porosityModel/porosityModel.H
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2012-2018 OpenFOAM Foundation
+    Copyright (C) 2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -44,7 +45,6 @@ SourceFiles
 #include "runTimeSelectionTables.H"
 #include "coordinateSystem.H"
 #include "dimensionedVector.H"
-#include "keyType.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -70,7 +70,7 @@ class porosityModel
 
 protected:
 
-    // Protected data
+    // Protected Data
 
         //- Porosity name
         word name_;
@@ -88,7 +88,7 @@ protected:
         bool active_;
 
         //- Name(s) of cell-zone
-        keyType zoneName_;
+        wordRe zoneName_;
 
         //- Cell zone IDs
         labelList cellZoneIDs_;
diff --git a/src/finiteVolume/fvMesh/fvBoundaryMesh/fvBoundaryMesh.C b/src/finiteVolume/fvMesh/fvBoundaryMesh/fvBoundaryMesh.C
index 0377d7c10b..b3d70e1c34 100644
--- a/src/finiteVolume/fvMesh/fvBoundaryMesh/fvBoundaryMesh.C
+++ b/src/finiteVolume/fvMesh/fvBoundaryMesh/fvBoundaryMesh.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2018-2020 OpenCFD Ltd.
+    Copyright (C) 2018-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -75,11 +75,11 @@ Foam::fvBoundaryMesh::fvBoundaryMesh
 
 Foam::labelList Foam::fvBoundaryMesh::indices
 (
-    const keyType& key,
+    const wordRe& matcher,
     const bool useGroups
 ) const
 {
-    return mesh().boundaryMesh().indices(key, useGroups);
+    return mesh().boundaryMesh().indices(matcher, useGroups);
 }
 
 
diff --git a/src/finiteVolume/fvMesh/fvBoundaryMesh/fvBoundaryMesh.H b/src/finiteVolume/fvMesh/fvBoundaryMesh/fvBoundaryMesh.H
index 568e3fbe9a..31c27e34a6 100644
--- a/src/finiteVolume/fvMesh/fvBoundaryMesh/fvBoundaryMesh.H
+++ b/src/finiteVolume/fvMesh/fvBoundaryMesh/fvBoundaryMesh.H
@@ -110,8 +110,8 @@ public:
         lduInterfacePtrsList interfaces() const;
 
         //- Return patch indices for all matches.
-        //  A no-op (returns empty list) for an empty key
-        labelList indices(const keyType& key, const bool useGroups) const;
+        //  A no-op (returns empty list) for an empty matcher
+        labelList indices(const wordRe& matcher, const bool useGroups) const;
 
         //- Find patch index given a name
         //  A no-op (returns -1) for an empty patchName
@@ -137,7 +137,7 @@ public:
 
         //- Identical to the indices() method (AUG-2018)
         FOAM_DEPRECATED_FOR(2018-08, "indices() method")
-        labelList findIndices(const keyType& key, const bool useGroups) const
+        labelList findIndices(const wordRe& key, bool useGroups) const
         {
             return indices(key, useGroups);
         }
diff --git a/src/functionObjects/field/externalCoupled/externalCoupled.C b/src/functionObjects/field/externalCoupled/externalCoupled.C
index 18706366eb..72ef873874 100644
--- a/src/functionObjects/field/externalCoupled/externalCoupled.C
+++ b/src/functionObjects/field/externalCoupled/externalCoupled.C
@@ -278,7 +278,7 @@ void Foam::functionObjects::externalCoupled::writeGeometry
         (
             mesh.boundaryMesh().patchSet
             (
-                List<wordRe>{groupName}
+                wordRes(one{}, groupName)
             ).sortedToc()
         );
 
diff --git a/src/functionObjects/field/externalCoupled/externalCoupledTemplates.C b/src/functionObjects/field/externalCoupled/externalCoupledTemplates.C
index e3e8a3a240..34e99f6297 100644
--- a/src/functionObjects/field/externalCoupled/externalCoupledTemplates.C
+++ b/src/functionObjects/field/externalCoupled/externalCoupledTemplates.C
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2015-2020 OpenCFD Ltd.
+    Copyright (C) 2015-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -80,7 +80,10 @@ bool Foam::functionObjects::externalCoupled::readData
     }
 
 
+    const wordRes patchSelection(one{}, groupName);
+
     label nFound = 0;
+
     for (const fvMesh& mesh : meshes)
     {
         const volFieldType* vfptr = mesh.findObject<volFieldType>(fieldName);
@@ -89,7 +92,7 @@ bool Foam::functionObjects::externalCoupled::readData
         {
             continue;
         }
-        nFound++;
+        ++nFound;
 
         typename volFieldType::Boundary& bf =
             const_cast<volFieldType*>(vfptr)->boundaryFieldRef();
@@ -97,10 +100,7 @@ bool Foam::functionObjects::externalCoupled::readData
         // Get the patches
         const labelList patchIDs
         (
-            mesh.boundaryMesh().patchSet
-            (
-                List<wordRe>{groupName}
-            ).sortedToc()
+            mesh.boundaryMesh().patchSet(patchSelection).sortedToc()
         );
 
         // Handle column-wise reading of patch data. Supports most easy types
@@ -261,7 +261,7 @@ bool Foam::functionObjects::externalCoupled::readData
         }
     }
 
-    return nFound > 0;
+    return nFound;
 }
 
 
@@ -352,8 +352,9 @@ bool Foam::functionObjects::externalCoupled::writeData
     }
 
 
-    bool headerDone = false;
+    const wordRes patchSelection(one{}, groupName);
 
+    bool headerDone = false;
     label nFound = 0;
 
     for (const fvMesh& mesh : meshes)
@@ -364,7 +365,7 @@ bool Foam::functionObjects::externalCoupled::writeData
         {
             continue;
         }
-        nFound++;
+        ++nFound;
 
         const typename volFieldType::Boundary& bf =
             vfptr->boundaryField();
@@ -372,10 +373,7 @@ bool Foam::functionObjects::externalCoupled::writeData
         // Get the patches
         const labelList patchIDs
         (
-            mesh.boundaryMesh().patchSet
-            (
-                List<wordRe>{groupName}
-            ).sortedToc()
+            mesh.boundaryMesh().patchSet(patchSelection).sortedToc()
         );
 
         // Handle column-wise writing of patch data. Supports most easy types
@@ -474,7 +472,7 @@ bool Foam::functionObjects::externalCoupled::writeData
         }
     }
 
-    return nFound > 0;
+    return nFound;
 }
 
 
diff --git a/src/lagrangian/intermediate/submodels/CloudFunctionObjects/ParticleErosion/ParticleErosion.C b/src/lagrangian/intermediate/submodels/CloudFunctionObjects/ParticleErosion/ParticleErosion.C
index 228ee73c2c..9958881f04 100644
--- a/src/lagrangian/intermediate/submodels/CloudFunctionObjects/ParticleErosion/ParticleErosion.C
+++ b/src/lagrangian/intermediate/submodels/CloudFunctionObjects/ParticleErosion/ParticleErosion.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
-    Copyright (C) 2019-2020 OpenCFD Ltd.
+    Copyright (C) 2019-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -67,15 +67,7 @@ Foam::label Foam::ParticleErosion<CloudType>::applyToPatch
     const label globalPatchi
 ) const
 {
-    forAll(patchIDs_, i)
-    {
-        if (patchIDs_[i] == globalPatchi)
-        {
-            return i;
-        }
-    }
-
-    return -1;
+    return patchIDs_.find(globalPatchi);
 }
 
 
@@ -120,7 +112,7 @@ Foam::ParticleErosion<CloudType>::ParticleErosion
     labelHashSet uniqIds;
     for (const wordRe& re : patchNames)
     {
-        labelList ids = findStrings(re, allPatchNames);
+        labelList ids = findMatchingStrings(re, allPatchNames);
 
         if (ids.empty())
         {
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionData.C b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionData.C
index a2f5686c78..1645ea93a5 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionData.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionData.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -34,39 +34,13 @@ License
 
 Foam::patchInteractionData::patchInteractionData()
 :
-    interactionTypeName_("unknownInteractionTypeName"),
-    patchName_("unknownPatch"),
-    e_(0.0),
-    mu_(0.0)
+    interactionTypeName_(),
+    patchName_(),
+    e_(0),
+    mu_(0)
 {}
 
 
-// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
-
-const Foam::word& Foam::patchInteractionData::interactionTypeName() const
-{
-    return interactionTypeName_;
-}
-
-
-const Foam::keyType& Foam::patchInteractionData::patchName() const
-{
-    return patchName_;
-}
-
-
-Foam::scalar Foam::patchInteractionData::e() const
-{
-    return e_;
-}
-
-
-Foam::scalar Foam::patchInteractionData::mu() const
-{
-    return mu_;
-}
-
-
 // * * * * * * * * * * * * * * * IOstream Operators  * * * * * * * * * * * * //
 
 Foam::Istream& Foam::operator>>
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionData.H b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionData.H
index 7d9e818d06..6dba9eb95f 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionData.H
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionData.H
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
+    Copyright (C) 2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -34,36 +35,31 @@ Description
 #ifndef patchInteractionData_H
 #define patchInteractionData_H
 
-#include "Istream.H"
+#include "wordRe.H"
+#include "scalar.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 namespace Foam
 {
+
+// Forward Declaration
+class patchInteractionData;
+Istream& operator>>(Istream& is, patchInteractionData& pid);
+
 /*---------------------------------------------------------------------------*\
                     Class patchInteractionData Declaration
 \*---------------------------------------------------------------------------*/
 
-// Forward declaration of classes
-class patchInteractionData;
-
-// Forward declaration of friend functions
-Istream& operator>>
-(
-    Istream& is,
-    patchInteractionData& pid
-);
-
-
 class patchInteractionData
 {
-    // Private data
+    // Private Data
 
         //- Interaction type name
         word interactionTypeName_;
 
-        //- Patch name
-        keyType patchName_;
+        //- Patch name(s)
+        wordRe patchName_;
 
         //- Elasticity coefficient
         scalar e_;
@@ -76,35 +72,41 @@ public:
 
     // Constructor
 
-        //- Construct null
+        //- Default construct
         patchInteractionData();
 
 
-    // Member functions
+    // Member Functions
 
-        // Access
+        //- The interaction type name
+        const word& interactionTypeName() const noexcept
+        {
+            return interactionTypeName_;
+        }
 
-            //- Return const access to the interaction type name
-            const word& interactionTypeName() const;
+        //- The patch name(s)
+        const wordRe& patchName() const noexcept
+        {
+            return patchName_;
+        }
 
-            //- Return const access to the patch name
-            const keyType& patchName() const;
+        //- The elasticity coefficient
+        scalar e() const noexcept
+        {
+            return e_;
+        }
 
-            //- Return const access to the elasticity coefficient
-            scalar e() const;
-
-            //- Return const access to the restitution coefficient
-            scalar mu() const;
+        //- The restitution coefficient
+        scalar mu() const noexcept
+        {
+            return mu_;
+        }
 
 
-        // I-O
+    // IO Operators
 
-            //- Istream operator
-            friend Istream& operator>>
-            (
-                Istream& is,
-                patchInteractionData& pid
-            );
+        //- Istream operator
+        friend Istream& operator>>(Istream& is, patchInteractionData& pid);
 };
 
 
diff --git a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.C b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.C
index 07ade8be9f..63ecd27710 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/PatchInteractionModel/LocalInteraction/patchInteractionDataList.C
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
+    Copyright (C) 2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -50,14 +51,14 @@ Foam::patchInteractionDataList::patchInteractionDataList
     const List<patchInteractionData>& items = *this;
     forAllReverse(items, i)
     {
-        const keyType& patchName = items[i].patchName();
+        const wordRe& patchName = items[i].patchName();
         labelList ids = bMesh.indices(patchName);
 
         if (ids.empty())
         {
             WarningInFunction
-                << "Cannot find any patch names matching " << patchName
-                << endl;
+                << "Cannot find any patch names matching "
+                << patchName << endl;
         }
 
         patchGroupIDs_[i].transfer(ids);
@@ -65,9 +66,8 @@ Foam::patchInteractionDataList::patchInteractionDataList
 
     // Check that all patches are specified
     DynamicList<word> badPatches;
-    forAll(bMesh, patchi)
+    for (const polyPatch& pp : bMesh)
     {
-        const polyPatch& pp = bMesh[patchi];
         if
         (
             !pp.coupled()
@@ -79,12 +79,13 @@ Foam::patchInteractionDataList::patchInteractionDataList
         }
     }
 
-    if (badPatches.size() > 0)
+    if (!badPatches.empty())
     {
         FatalErrorInFunction
             << "All patches must be specified when employing local patch "
             << "interaction. Please specify data for patches:" << nl
-            << badPatches << nl << exit(FatalError);
+            << badPatches << nl
+            << exit(FatalError);
     }
 }
 
@@ -103,15 +104,11 @@ Foam::patchInteractionDataList::patchInteractionDataList
 
 Foam::label Foam::patchInteractionDataList::applyToPatch(const label id) const
 {
-    forAll(patchGroupIDs_, groupI)
+    forAll(patchGroupIDs_, groupi)
     {
-        const labelList& patchIDs = patchGroupIDs_[groupI];
-        forAll(patchIDs, patchi)
+        if (patchGroupIDs_[groupi].found(id))
         {
-            if (patchIDs[patchi] == id)
-            {
-                return groupI;
-            }
+            return groupi;
         }
     }
 
diff --git a/src/mesh/blockMesh/blockMeshTools/blockMeshTools.C b/src/mesh/blockMesh/blockMeshTools/blockMeshTools.C
index be91dbc674..350635bc7c 100644
--- a/src/mesh/blockMesh/blockMeshTools/blockMeshTools.C
+++ b/src/mesh/blockMesh/blockMeshTools/blockMeshTools.C
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016 OpenFOAM Foundation
+    Copyright (C) 2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -27,6 +28,29 @@ License
 
 #include "blockMeshTools.H"
 
+// * * * * * * * * * * * * * * * Local Functions * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+static inline const Foam::entry* resolveLabel(const entry& e, const label val)
+{
+    if (e.isStream())
+    {
+        const tokenList& toks = e.stream();
+
+        if (!toks.empty() && toks[0].isLabel(val))
+        {
+            return &e;
+        }
+    }
+
+    return nullptr;
+}
+
+} // End namespace Foam
+
+
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 void Foam::blockMeshTools::read
@@ -93,21 +117,18 @@ void Foam::blockMeshTools::write
 {
     for (const entry& e : dict)
     {
-        if (e.isStream())
+        const entry* eptr = resolveLabel(e, val);
+        if (eptr)
         {
-            label keyVal(Foam::readLabel(e.stream()));
-            if (keyVal == val)
-            {
-                os << e.keyword();
-                return;
-            }
+            os << eptr->keyword();
+            return;
         }
     }
     os << val;
 }
 
 
-const Foam::keyType& Foam::blockMeshTools::findEntry
+const Foam::entry* Foam::blockMeshTools::findEntry
 (
     const dictionary& dict,
     const label val
@@ -115,17 +136,14 @@ const Foam::keyType& Foam::blockMeshTools::findEntry
 {
     for (const entry& e : dict)
     {
-        if (e.isStream())
+        const entry* eptr = resolveLabel(e, val);
+        if (eptr)
         {
-            label keyVal(Foam::readLabel(e.stream()));
-            if (keyVal == val)
-            {
-                return e.keyword();
-            }
+            return eptr;
         }
     }
 
-    return keyType::null;
+    return nullptr;
 }
 
 
diff --git a/src/mesh/blockMesh/blockMeshTools/blockMeshTools.H b/src/mesh/blockMesh/blockMeshTools/blockMeshTools.H
index e6884fba83..11e9ef199a 100644
--- a/src/mesh/blockMesh/blockMeshTools/blockMeshTools.H
+++ b/src/mesh/blockMesh/blockMeshTools/blockMeshTools.H
@@ -50,11 +50,11 @@ namespace blockMeshTools
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
     //- In-place read with dictionary lookup
-    void read(Istream&, label&, const dictionary&);
+    void read(Istream&, label& val, const dictionary&);
 
     //- In-place read with dictionary lookup
     template<class T>
-    void read(Istream&, List<T>&, const dictionary&);
+    void read(Istream&, List<T>& list, const dictionary&);
 
     //- Return-read with dictionary lookup
     label read(Istream&, const dictionary&);
@@ -64,10 +64,10 @@ namespace blockMeshTools
     List<T> read(Istream& is, const dictionary&);
 
     //- Write with dictionary lookup
-    void write(Ostream&, const label, const dictionary&);
+    void write(Ostream&, const label val, const dictionary&);
 
-    //- Linear search for label entry
-    const keyType& findEntry(const dictionary&, const label);
+    //- Linear search for labelled entry, nullptr if not found
+    const entry* findEntry(const dictionary& dict, const label val);
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
diff --git a/src/mesh/snappyHexMesh/snappyHexMeshDriver/layerParameters/layerParameters.C b/src/mesh/snappyHexMesh/snappyHexMeshDriver/layerParameters/layerParameters.C
index 4d34c5c3bb..62b50bb0c5 100644
--- a/src/mesh/snappyHexMesh/snappyHexMeshDriver/layerParameters/layerParameters.C
+++ b/src/mesh/snappyHexMesh/snappyHexMeshDriver/layerParameters/layerParameters.C
@@ -532,7 +532,7 @@ Foam::layerParameters::layerParameters
 
             const labelHashSet patchIDs
             (
-                boundaryMesh.patchSet(List<wordRe>(1, wordRe(key)))
+                boundaryMesh.patchSet(wordRes(one{}, wordRe(key)))
             );
 
             if (patchIDs.size() == 0)
diff --git a/src/meshTools/coordinate/systems/coordinateSystems.C b/src/meshTools/coordinate/systems/coordinateSystems.C
index 944fb6ded5..94cab825d4 100644
--- a/src/meshTools/coordinate/systems/coordinateSystems.C
+++ b/src/meshTools/coordinate/systems/coordinateSystems.C
@@ -179,24 +179,13 @@ const Foam::coordinateSystems& Foam::coordinateSystems::New
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-Foam::labelList Foam::coordinateSystems::indices(const keyType& key) const
+Foam::labelList Foam::coordinateSystems::indices(const wordRe& key) const
 {
     if (key.empty())
     {
         return labelList();
     }
-    else if (key.isPattern())
-    {
-        // Match as regex
-        const regExp matcher(key);
-        return PtrListOps::findMatching(*this, matcher);
-    }
-    else
-    {
-        // Compare as literal string
-        const word& matcher = key;
-        return PtrListOps::findMatching(*this, matcher);
-    }
+    return PtrListOps::findMatching(*this, key);
 }
 
 
@@ -210,24 +199,13 @@ Foam::labelList Foam::coordinateSystems::indices(const wordRes& matcher) const
 }
 
 
-Foam::label Foam::coordinateSystems::findIndex(const keyType& key) const
+Foam::label Foam::coordinateSystems::findIndex(const wordRe& key) const
 {
     if (key.empty())
     {
         return -1;
     }
-    else if (key.isPattern())
-    {
-        // Find as regex
-        const regExp matcher(key);
-        return PtrListOps::firstMatching(*this, matcher);
-    }
-    else
-    {
-        // Find as literal string
-        const word& matcher = key;
-        return PtrListOps::firstMatching(*this, matcher);
-    }
+    return PtrListOps::firstMatching(*this, key);
 }
 
 
@@ -241,7 +219,7 @@ Foam::label Foam::coordinateSystems::findIndex(const wordRes& matcher) const
 }
 
 
-bool Foam::coordinateSystems::found(const keyType& key) const
+bool Foam::coordinateSystems::found(const wordRe& key) const
 {
     return findIndex(key) != -1;
 }
@@ -250,13 +228,16 @@ bool Foam::coordinateSystems::found(const keyType& key) const
 const Foam::coordinateSystem*
 Foam::coordinateSystems::cfind(const word& name) const
 {
-    const label index = this->findIndex(name);
+    const label index =
+    (
+        name.empty() ? -1 : PtrListOps::firstMatching(*this, name)
+    );
 
     if (coordinateSystem::debug)
     {
         InfoInFunction
             << "Global coordinate system: "
-            << name << "=" << index << endl;
+            << name << '=' << index << endl;
     }
 
     if (index < 0)
@@ -271,9 +252,9 @@ Foam::coordinateSystems::cfind(const word& name) const
 const Foam::coordinateSystem&
 Foam::coordinateSystems::lookup(const word& name) const
 {
-    const label index = this->findIndex(name);
+    const coordinateSystem* ptr = this->cfind(name);
 
-    if (index < 0)
+    if (!ptr)
     {
         FatalErrorInFunction
             << "Could not find coordinate system: " << name << nl
@@ -281,14 +262,8 @@ Foam::coordinateSystems::lookup(const word& name) const
             << flatOutput(names()) << nl << nl
             << exit(FatalError);
     }
-    if (coordinateSystem::debug)
-    {
-        InfoInFunction
-            << "Global coordinate system: "
-            << name << "=" << index << endl;
-    }
 
-    return this->operator[](index);
+    return *ptr;
 }
 
 
@@ -298,34 +273,13 @@ Foam::wordList Foam::coordinateSystems::names() const
 }
 
 
-Foam::wordList Foam::coordinateSystems::names(const keyType& key) const
+Foam::wordList Foam::coordinateSystems::names(const wordRe& key) const
 {
     if (key.empty())
     {
         return wordList();
     }
-    else if (key.isPattern())
-    {
-        // Find as regex
-        const regExp matcher(key);
-        return PtrListOps::names(*this, matcher);
-    }
-    else
-    {
-        // Find as literal string
-        const word& matcher = key;
-        return PtrListOps::names(*this, matcher);
-    }
-}
-
-
-Foam::wordList Foam::coordinateSystems::names(const wordRe& matcher) const
-{
-    if (matcher.empty())
-    {
-        return wordList();
-    }
-    return PtrListOps::names(*this, matcher);
+    return PtrListOps::names(*this, key);
 }
 
 
diff --git a/src/meshTools/coordinate/systems/coordinateSystems.H b/src/meshTools/coordinate/systems/coordinateSystems.H
index d1af2a795b..eb81ff231b 100644
--- a/src/meshTools/coordinate/systems/coordinateSystems.H
+++ b/src/meshTools/coordinate/systems/coordinateSystems.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2018-2020 OpenCFD Ltd.
+    Copyright (C) 2018-2021 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -134,7 +134,7 @@ public:
 
         //- Find and return indices for all matches
         //  A no-op (returns empty list) for an empty key
-        labelList indices(const keyType& key) const;
+        labelList indices(const wordRe& key) const;
 
         //- Find and return indices for all matches
         //  A no-op (returns empty list) for an empty matcher
@@ -142,14 +142,14 @@ public:
 
         //- Find and return index for the first match, return -1 if not found
         //  A no-op (returns -1) for an empty key
-        label findIndex(const keyType& key) const;
+        label findIndex(const wordRe& key) const;
 
         //- Find and return index for the first match, return -1 if not found
         //  A no-op (returns -1) for an empty matcher
         label findIndex(const wordRes& matcher) const;
 
         //- Search if given key exists
-        bool found(const keyType& key) const;
+        bool found(const wordRe& key) const;
 
         //- Return pointer to named coordinateSystem or nullptr on error
         const coordinateSystem* cfind(const word& name) const;
@@ -161,10 +161,7 @@ public:
         wordList names() const;
 
         //- A list of the coordinate-system names satisfying the input matcher
-        wordList names(const keyType& key) const;
-
-        //- A list of the coordinate-system names satisfying the input matcher
-        wordList names(const wordRe& matcher) const;
+        wordList names(const wordRe& key) const;
 
         //- A list of the coordinate-system names satisfying the input matcher
         wordList names(const wordRes& matcher) const;
@@ -193,7 +190,7 @@ public:
 
         //- Identical to the indices() method (AUG-2018)
         FOAM_DEPRECATED_FOR(2018-08, "indices() method")
-        labelList findIndices(const keyType& key) const
+        labelList findIndices(const wordRe& key) const
         {
             return this->indices(key);
         }