ENH: rationalize expression string reading

- read construct from dictionary.
  Calling syntax similar to dimensionedType, dimensionedSet,...

  Replaces the older getEntry(), getOptional() static methods

- support readIfPresent

src/OpenFOAM/expressions/exprString/exprString.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2019-2021 OpenCFD Ltd.
+    Copyright (C) 2019-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -28,6 +28,7 @@ License
 #include "exprString.H"
 #include "stringOps.H"
 #include "expressionEntry.H"
+#include "error.H"
 
 // * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
 
@@ -47,36 +48,6 @@ void Foam::expressions::exprString::inplaceExpand
 }
 
 
-Foam::expressions::exprString
-Foam::expressions::exprString::getEntry
-(
-    const word& key,
-    const dictionary& dict,
-    const bool stripComments
-)
-{
-    exprString expr;
-    expr.readEntry(key, dict, true, stripComments);  // mandatory
-
-    return expr;
-}
-
-
-Foam::expressions::exprString
-Foam::expressions::exprString::getOptional
-(
-    const word& key,
-    const dictionary& dict,
-    const bool stripComments
-)
-{
-    exprString expr;
-    expr.readEntry(key, dict, false, stripComments);  // optional
-
-    return expr;
-}
-
-
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 void Foam::expressions::exprString::expand
@@ -103,15 +74,14 @@ bool Foam::expressions::exprString::readEntry
 (
     const word& keyword,
     const dictionary& dict,
-    bool mandatory,
-    const bool stripComments
+    bool mandatory
 )
 {
     const bool ok = dict.readEntry(keyword, *this, keyType::LITERAL, mandatory);
 
     if (ok && !empty())
     {
-        this->expand(dict, stripComments);  // strip comments
+        this->expand(dict, true);  // strip comments
     }
     else
     {

src/OpenFOAM/expressions/exprString/exprString.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2012-2018 Bernhard Gschaider
-    Copyright (C) 2019-2021 OpenCFD Ltd.
+    Copyright (C) 2019-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -40,8 +40,8 @@ SeeAlso
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef expressions_exprString_H
-#define expressions_exprString_H
+#ifndef Foam_expressions_exprString_H
+#define Foam_expressions_exprString_H
 
 #include "string.H"
 #include "dictionary.H"
@@ -75,34 +75,26 @@ public:
         exprString(exprString&& rhs) = default;
 
         //- Copy construct from std::string
-        inline explicit exprString(const std::string& s, bool doValidate=true);
+        inline explicit exprString(const std::string& s, bool doCheck=true);
 
         //- Move construct from std::string
-        inline explicit exprString(std::string&& s, bool doValidate=true);
+        inline explicit exprString(std::string&& s, bool doCheck=true);
 
         //- Construct as copy of character array
-        inline explicit exprString(const char* s, bool doValidate=true);
+        inline explicit exprString(const char* s, bool doCheck=true);
 
-        //- Copy construct and expand with dictionary variables,
-        //- and strip C/C++ comments from the input
+        //- Construct from dictionary entry lookup.
+        //- Expands dictionary variables and strips and strips any
+        //- embedded C/C++ comments
         inline exprString
         (
-            const std::string& str,
+            const word& entryName,  //!< Lookup key. LITERAL (not REGEX)
             const dictionary& dict,
-            const bool stripComments = true
+            const bool mandatory = true
         );
 
-        //- Move construct and expand with dictionary variables,
-        //- and strip C/C++ comments from the input
-        inline exprString
-        (
-            std::string&& str,
-            const dictionary& dict,
-            const bool stripComments = true
-        );
-
-        //- Construct from Istream and expand with dictionary variables,
-        //- and strip C/C++ comments from the input
+        //- Construct from Istream with dictionary context for expanding
+        //- dictionary variables. Strips any embedded C/C++ comments
         inline exprString
         (
             Istream& is,
@@ -117,8 +109,38 @@ public:
 
     // Static Member Functions
 
+        //- Copy convert string to exprString.
+        //  No expansions, know what you are doing.
+        inline static exprString toExpr(const std::string& str);
+
+        //- Move convert string to exprString.
+        //  No expansions, know what you are doing.
+        inline static exprString toExpr(std::string&& str);
+
+        //- Copy convert string to exprString with dictionary expansions,
+        //- stripping any embedded C/C++ comments
+        //
+        // \sa inplaceExpand() for expansion details
+        static exprString toExpr
+        (
+            const std::string& str,
+            const dictionary& dict,
+            const bool stripComments = true
+        );
+
+        //- Move convert string to exprString with dictionary expansions,
+        //- stripping any embedded C/C++ comments
+        //
+        // \sa inplaceExpand() for expansion details
+        static exprString toExpr
+        (
+            std::string&& str,
+            const dictionary& dict,
+            const bool stripComments = true
+        );
+
         //- Inplace expansion with dictionary variables,
-        //- and strip C/C++ comments from the input.
+        //- and strip any embedded C/C++ comments
         //
         // \par Expansion behaviour
         // - alternatives = True
@@ -133,34 +155,6 @@ public:
             const bool stripComments = true
         );
 
-        //- Get and expand expression with dictionary entries,
-        //- optionally strip C/C++ comments from the input.
-        // Expansion behaviour as per inplaceExpand
-        static exprString getEntry
-        (
-            const word& keyword,  //!< Lookup key. Uses LITERAL (not REGEX)
-            const dictionary& dict,
-            const bool stripComments = true
-        );
-
-        //- Get and expand expression with dictionary entries,
-        //- optionally strip C/C++ comments from the input.
-        // Expansion behaviour as per inplaceExpand
-        static exprString getOptional
-        (
-            const word& keyword,  //!< Lookup key. Uses LITERAL (not REGEX)
-            const dictionary& dict,
-            const bool stripComments = true
-        );
-
-        //- Copy convert string to exprString.
-        //  No expansions, know what you are doing.
-        inline static exprString toExpr(const std::string& str);
-
-        //- Move convert string to exprString.
-        //  No expansions, know what you are doing.
-        inline static exprString toExpr(std::string&& str);
-
 
     // Member Functions
 
@@ -168,20 +162,28 @@ public:
         inline bool valid() const;
 
         //- Inplace expansion with dictionary variables,
-        //- and strip C/C++ comments from the input
+        //- and strip any embedded C/C++ comments.
+        //  \sa inplaceExpand() for expansion details
         void expand(const dictionary& dict, const bool stripComments = true);
 
         //- Inplace trim leading and trailing whitespace
         void trim();
 
         //- Read/expand entry with dictionary variables,
-        //- and strip C/C++ comments from the input
+        //- and strip any embedded C/C++ comments from the input
         bool readEntry
         (
             const word& keyword,  //!< Lookup key. Uses LITERAL (not REGEX)
             const dictionary& dict,
-            bool mandatory = true,
-            const bool stripComments = true
+            bool mandatory = true
+        );
+
+        //- Read/expand optional entry with dictionary variables,
+        //- and strip any embedded C/C++ comments from the input
+        inline bool readIfPresent
+        (
+            const word& keyword,  //!< Lookup key. Uses LITERAL (not REGEX)
+            const dictionary& dict
         );
 
 
@@ -206,7 +208,7 @@ public:
     // Write
 
         //- Dictionary entry for expression string, normally suppressing
-        //- empty strings. Generally used verbatim output (readability)
+        //- empty strings. Generally uses verbatim output (readability)
         //  \return true if entry was written
         bool writeEntry
         (

src/OpenFOAM/expressions/exprString/exprStringI.H

@@ -5,8 +5,8 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Original code Copyright (C) 2012-2018 Bernhard Gschaider
-    Copyright (C) 2019 OpenCFD Ltd.
+    Copyright (C) 2012-2018 Bernhard Gschaider
+    Copyright (C) 2019-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -33,13 +33,13 @@ License
 inline Foam::expressions::exprString::exprString
 (
     const std::string& s,
-    bool doValidate
+    bool doCheck
 )
 :
     string(s)
 {
     #ifdef FULLDEBUG
-    if (doValidate)
+    if (doCheck)
     {
         (void)valid();
     }
@@ -50,13 +50,13 @@ inline Foam::expressions::exprString::exprString
 inline Foam::expressions::exprString::exprString
 (
     std::string&& s,
-    bool doValidate
+    bool doCheck
 )
 :
     string(std::move(s))
 {
     #ifdef FULLDEBUG
-    if (doValidate)
+    if (doCheck)
     {
         (void)valid();
     }
@@ -67,13 +67,13 @@ inline Foam::expressions::exprString::exprString
 inline Foam::expressions::exprString::exprString
 (
     const char* s,
-    bool doValidate
+    bool doCheck
 )
 :
     string(s)
 {
     #ifdef FULLDEBUG
-    if (doValidate)
+    if (doCheck)
     {
         (void)valid();
     }
@@ -83,27 +83,19 @@ inline Foam::expressions::exprString::exprString
 
 inline Foam::expressions::exprString::exprString
 (
-    const std::string& str,
+    const word& entryName,
     const dictionary& dict,
-    const bool removeComments
+    const bool mandatory
 )
-:
-    string(str)
 {
-    expand(dict, removeComments);
-}
-
-
-inline Foam::expressions::exprString::exprString
-(
-    std::string&& str,
-    const dictionary& dict,
-    const bool removeComments
-)
-:
-    string(std::move(str))
-{
-    expand(dict, removeComments);
+    if (mandatory)
+    {
+        readEntry(entryName, dict);
+    }
+    else
+    {
+        readIfPresent(entryName, dict);
+    }
 }
 
 
@@ -120,6 +112,64 @@ inline Foam::expressions::exprString::exprString
 }
 
 
+// * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
+
+inline Foam::expressions::exprString
+Foam::expressions::exprString::toExpr(const std::string& str)
+{
+    exprString expr;
+
+    expr.string::operator=(str);
+
+    return expr;
+}
+
+
+inline Foam::expressions::exprString
+Foam::expressions::exprString::toExpr(std::string&& str)
+{
+    exprString expr;
+
+    expr.string::operator=(std::move(str));
+
+    return expr;
+}
+
+
+inline Foam::expressions::exprString
+Foam::expressions::exprString::toExpr
+(
+    const std::string& str,
+    const dictionary& dict,
+    const bool stripComments
+)
+{
+    // Copy - no validate
+    exprString expr(str, false);
+
+    expr.expand(dict, stripComments);
+
+    return expr;
+}
+
+
+inline Foam::expressions::exprString
+Foam::expressions::exprString::toExpr
+(
+    std::string&& str,
+    const dictionary& dict,
+    const bool stripComments
+)
+{
+    // Move - no validate
+    exprString expr(std::move(str), false);
+
+    expr.expand(dict, stripComments);
+
+    return expr;
+}
+
+
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 inline bool Foam::expressions::exprString::valid() const
@@ -139,25 +189,13 @@ inline bool Foam::expressions::exprString::valid() const
 }
 
 
-inline Foam::expressions::exprString
-Foam::expressions::exprString::toExpr(const std::string& str)
+inline bool Foam::expressions::exprString::readIfPresent
+(
+    const word& key,
+    const dictionary& dict
+)
 {
-    exprString expr;
-
-    expr.string::operator=(str);
-
-    return expr;
-}
-
-
-inline Foam::expressions::exprString
-Foam::expressions::exprString::toExpr(std::string&& str)
-{
-    exprString expr;
-
-    expr.string::operator=(std::move(str));
-
-    return expr;
+    return readEntry(key, dict, false);  // non-mandatory
 }