ENH: adjust token in preparation for separate expression tokenization

- minor simplification of #if/#endif handling

ENH: improve input robustness with negative-prefixed expansions (#2095)

- especially in blockMeshDict it is useful to negate an value directly.
  Eg,
  ```
     xmax  100;
     xmin  -$xmax;
  ```
  However, this fails since the dictionary expansion is a two-step
  process of tokenization followed by expansion. After the expansion
  the given input would now be the following:
  ```
     xmax  100;
     xmin  - 100;
  ```
  and retrieving a scalar value for 'xmin' fails.

  Counteract this by being more generous on tokenized input when
  attempting to retrieve a label or scalar value.
  If a '-' is found where a number is expected, use it to negate the
  subsequent value.

  The previous solution was to invoke an 'eval':
  ```
     xmax  100;
     xmin  #eval{-$xmax};
  ```
  which adds additional clutter.

applications/test/dictionary/testDict

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDict;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

applications/test/dictionary/testDict2

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDict;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

applications/test/dictionary/testDictAPI

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDict;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

applications/test/dictionary/testDictCalc1

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDictCalc1;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

applications/test/dictionary/testDictEval1

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDictEval1;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

applications/test/dictionary/testDictEval2

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDictEval1;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

applications/test/dictionary/testDictEval3

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDictEval1;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

applications/test/dictionary/testDictEval4

@@ -0,0 +1,121 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  v2012                                 |
+|   \\  /    A nd           | Website:  www.openfoam.com                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    object      dictionary;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+// Test expansion with negative signs
+
+value   0.5;
+
+radius  3;
+
+negValue  -$value;
+
+select1 10;
+
+sqrt05  #eval{ sqrt(0.5) };
+
+vector  ( -10 ${{-$sqrt05}} $value );
+
+corner   ( ${{ -$radius*sqrt(0.5) }} 1 0 );
+
+corner2  ${{
+    vector(-${radius}*sqrt(0.5), ${radius}*sqrt(0.5), 2)
+}};
+
+
+// Just a future idea (2021-05-14) - does not yet work!
+#if 0
+corner3 #eval #{
+    variables ( "outer = $radius*sqrt(0.5)" );
+    vector(-outer, outer, 2)
+#};
+#endif
+
+
+// The brace-bracket #eval with multi-lines failed for v2012 and earlier
+
+corner2b  #eval
+{
+    vector(-${radius}*sqrt(0.5), $radius*sqrt(0.5), 2)
+};
+
+corner2c  #eval
+${{
+    vector(-${radius}*sqrt(0.5), $radius*sqrt(0.5), 2)
+}};
+
+
+longSlurp #eval
+{
+    // This is actually a very simple expression
+    1 + 2
+// With a long comment that is stripped out
+// during reading anyhow.
+};
+
+
+longVariable
+${{
+    // This is actually a very simple expression in variable syntax
+    1 + 2
+/*
+// With a long comment that is stripped out
+// during reading anyhow.
+*/
+}};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+// Geometric parameters
+rxo 2;
+ryo 3;
+rzo 4;
+
+// Geometric parameters
+outerRadius 1;
+innerRatio  0.75;
+
+geometry
+{
+    sphere
+    {
+        type    sphere;
+        origin  (0 0 0);
+        radius  ($rxo $ryo $rzo);
+    }
+
+    innerSphere
+    {
+        $sphere
+
+        // Different solutions to the same problem
+        radius_v1
+        (
+            ${{ $innerRatio*$rxo }}
+            ${{ $innerRatio*$ryo }}
+            ${{ $innerRatio*$rzo }}
+        );
+
+        radius_v2  #eval{ $innerRatio*vector($rxo, $ryo, $rzo) };
+        radius_v3  ${{ $innerRatio*$[(vector) ../sphere/radius] }};
+
+        // Inplace overwrite the same value
+        radius     ${{ $innerRatio*$[(vector) radius] }};
+    }
+}
+
+
+// ************************************************************************* //

applications/test/dictionary/testDictList

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDict;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 // Test some parsing

applications/test/dictionary/testDictRegex

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDictRegex;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 #inputMode  merge

applications/test/dictionary/testPrimitiveEntry

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDict;
+    object      dictionary;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

applications/test/dictionary/testSubkeyword

@@ -10,7 +10,7 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
-    object      testDict;
+    object      dictionary;
     note        "test with foamDictionary -expand";
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

applications/test/dictionary3/Make/files

@@ -0,0 +1,3 @@
+Test-dictionary3.C
+
+EXE = $(FOAM_USER_APPBIN)/Test-dictionary3

applications/test/dictionary3/Make/options

@@ -0,0 +1,2 @@
+/* EXE_INC = */
+/* EXE_LIBS = */

applications/test/dictionary3/Test-dictionary3.C

@@ -0,0 +1,78 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2021 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Application
+    Test-dictionary3
+
+Description
+    Test expressions and re-expansions
+
+\*---------------------------------------------------------------------------*/
+
+#include "argList.H"
+#include "IOstreams.H"
+#include "dictionary.H"
+#include "vector.H"
+#include "StringStream.H"
+
+using namespace Foam;
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+//  Main program:
+
+int main(int argc, char *argv[])
+{
+    argList::noParallel();
+
+    {
+        IStringStream is
+        (
+            "value   10;"
+            "scalar1 $value;"
+            "scalar2 -$value;"
+
+            // Use #eval expansion entirely
+            "vector1 ${{vector($value, -$value, $value)}};"
+            "vector2 ($value -$value $value);"
+        );
+
+        dictionary dict(is);
+
+        Info<< "input dictionary:" << dict << nl;
+
+        Info<< "value: " << dict.get<scalar>("value") << nl;
+
+        Info<< "scalar1: " << dict.get<scalar>("scalar1") << nl;
+        Info<< "scalar2: " << dict.get<scalar>("scalar2") << nl;
+
+        Info<< "vector1: " << dict.get<vector>("vector1") << nl;
+        Info<< "vector2: " << dict.get<vector>("vector2") << nl;
+    }
+
+    return 0;
+}
+
+
+// ************************************************************************* //