ENH: remove restricted precision for calc/eval (#2635)

- in earlier versions: used 'fixed' notation
  to force floating point numbers to be printed with at least
  some decimal digits. However, in the meantime we are more
  flexible with handling float/int input so remove this constraint.

- use ITstream::toString, which makes the string expansion of ${var}
  and the expression expansion of $[var] consistent.

applications/test/dictionary/testDictEval5

@@ -0,0 +1,39 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  v2306                                 |
+|   \\  /    A nd           | Website:  www.openfoam.com                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    object      dictionary;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+// Test evaluation with small values
+
+dp #eval{ sqrt(3./2.) *1e-3};
+a  #eval{ 2/sqrt(2.)*$dp };
+A_square #eval{ $a*$a };
+A_inlet #eval{ $A_square-2*degToRad(180)*$dp*$dp*0.25 };
+Q $A_inlet;
+Qerror #eval{$A_inlet};
+e #eval{0.2526944494428081};
+Uin #eval{ $Q/($A_square*$e) };
+
+// Bypass
+
+alt_dp #eval{ sqrt(3./2.) *1e-3};
+alt_a  #eval{ 2/sqrt(2.)*$[alt_dp] };
+alt_A_square #eval{ $[alt_a]*$[alt_a] };
+alt_A_inlet #eval{ $[alt_A_square]-2*degToRad(180)*$[alt_dp]*$[alt_dp]*0.25 };
+alt_Q $alt_A_inlet;
+alt_Qerror #eval{ $[alt_A_inlet] };
+alt_e #eval{0.2526944494428081};
+alt_Uin #eval{ $[alt_Q]/($[alt_A_square]*$[alt_e]) };
+
+// ************************************************************************* //

src/OpenFOAM/db/IOstreams/Tstreams/ITstream.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2015 OpenFOAM Foundation
-    Copyright (C) 2017-2022 OpenCFD Ltd.
+    Copyright (C) 2017-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -287,11 +287,11 @@ void Foam::ITstream::print(Ostream& os) const
     }
     else
     {
-        os  << toks.first().lineNumber();
+        os  << toks.front().lineNumber();
 
-        if (toks.first().lineNumber() < toks.last().lineNumber())
+        if (toks.front().lineNumber() < toks.back().lineNumber())
         {
-            os  << '-' << toks.last().lineNumber();
+            os  << '-' << toks.back().lineNumber();
         }
     }
     os  << ", ";
@@ -302,17 +302,22 @@ void Foam::ITstream::print(Ostream& os) const
 
 std::string Foam::ITstream::toString() const
 {
-    // NOTE: may wish to have special handling if there is a single token
+    const tokenList& toks = *this;
-    // and it is already a string or word
+    const label nToks = toks.size();
+
+    if (nToks == 1 && toks.front().isStringType())
+    {
+        // Already a string-type (WORD, STRING, ...). Just copy.
+        return toks.front().stringToken();
+    }
 
     OStringStream buf;
-    unsigned i = 0;
+    buf.precision(16);      // Some reasonably high precision
-    for (const token& tok : *this)
+    bool addSpace = false;  // Separate from previous token with a space
+    for (const token& tok : toks)
     {
-        if (i++)
+        if (addSpace) buf << token::SPACE;
-        {
+        addSpace = true;
-            buf << ' ';
-        }
         buf << tok;
     }
 
@@ -345,7 +350,7 @@ void Foam::ITstream::seek(label pos)
 
         if (nToks)
         {
-            lineNumber_ = toks.first().lineNumber();
+            lineNumber_ = toks.front().lineNumber();
         }
 
         setOpened();
@@ -358,7 +363,7 @@ void Foam::ITstream::seek(label pos)
 
         if (nToks)
         {
-            lineNumber_ = toks.last().lineNumber();
+            lineNumber_ = toks.back().lineNumber();
         }
 
         setEof();
@@ -461,7 +466,7 @@ Foam::Istream& Foam::ITstream::read(token& tok)
 
         if (nToks)
         {
-            tok.lineNumber(toks.last().lineNumber());
+            tok.lineNumber(toks.back().lineNumber());
         }
         else
         {

src/OpenFOAM/db/dictionary/functionEntries/calcEntry/calcEntry.C

@@ -87,13 +87,14 @@ Foam::string Foam::functionEntries::calcEntry::evaluate
     dictionary codeDict(parentDict, codeSubDict);
 
     // Use function to write stream
-    OStringStream os(is.format());
+    OStringStream buf(is.format());
+    buf.precision(16);      // Some reasonably high precision
 
     streamingFunctionType function = getFunction(parentDict, codeDict);
-    (*function)(os, parentDict);
+    (*function)(buf, parentDict);
 
     // Return evaluated content as string
-    return os.str();
+    return buf.str();
 }
 
 

src/OpenFOAM/expressions/exprEntry/expressionEntry.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2014-2018 Bernhard Gschaider
-    Copyright (C) 2019-2021 OpenCFD Ltd.
+    Copyright (C) 2019-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -238,18 +238,9 @@ void Foam::exprTools::expressionEntry::inplaceExpand
 
             if (castTo.empty())
             {
-                // Serialized with spaces
+                // Serialized with spaces - fails for non-primitiveEntry
                 ITstream& its = eptr->stream();
-
+                varValue = its.toString();
-                if (its.size() == 1 && its[0].isStringType())
-                {
-                    // Already a string-type (WORD, STRING, ...). Just copy.
-                    varValue = its[0].stringToken();
-                }
-                else
-                {
-                    varValue = its.toString();
-                }
             }
             else
             {

src/OpenFOAM/primitives/strings/stringOps/stringOps.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -231,33 +231,32 @@ static inline std::string entryToString
 
     if (eptr)
     {
-        OStringStream buf;
+        // Note, for OpenFOAM-v2212 and earlier: used 'fixed' notation
-        // Force floating point numbers to be printed with at least
+        // to force floating point numbers to be printed with at least
-        // some decimal digits.
+        // some decimal digits. However, in the meantime we are more
-        buf << fixed;
+        // flexible with handling float/int input so remove this constraint.
-        buf.precision(IOstream::defaultPrecision());
 
-        if (allowSubDict && eptr->isDict())
+        if (eptr->isDict())
         {
-            eptr->dict().write(buf, false);
+            if (allowSubDict)
-            str = buf.str();
-        }
-        else
-        {
-            // Fail for non-primitiveEntry
-            const auto& pe = dynamicCast<const primitiveEntry>(*eptr);
-
-            if (pe.size() == 1 && pe[0].isStringType())
             {
-                // Already a string-type (WORD, STRING, ...). Just copy.
+                OStringStream buf;
-                str = pe[0].stringToken();
+                buf.precision(16);  // Some reasonably high precision
+
+                eptr->dict().write(buf, false);
+                str = buf.str();
             }
             else
             {
-                pe.write(buf, true);
+                // Ignore silently...
-                str = buf.str();
             }
         }
+        else
+        {
+            // Serialized with spaces (primitiveEntry)
+            ITstream& its = eptr->stream();
+            return its.toString();
+        }
     }
 
     return str;