Modernize some of how program options emits help.

Alepha IOStreams supports adaptors for most of what used to be
temporary string functions.

ProgramOptions.cc

@@ -7,6 +7,7 @@ static_assert( __cplusplus > 2020'99 );
 
 #include <Alepha/Console.h>
 #include <Alepha/word_wrap.h>
+#include <Alepha/AutoRAII.h>
 #include <Alepha/error.h>
 
 #include <Alepha/Utility/StaticValue.h>
@@ -32,15 +33,6 @@ namespace Alepha::Hydrogen  ::detail::  ProgramOptions_m
 		{
 			using std::runtime_error::runtime_error;
 		};
-
-		// Print the string with wrapping to the terminal and the specified indent
-		// for subsequent lines.
-		void
-		printString( const std::string &s, const std::size_t indent )
-		{
-			const std::size_t width= getConsoleWidth();
-			std::cout << wordWrap( s, width, indent ) << std::endl;
-		}
 	}
 
 	struct impl::ProgramOption
@@ -202,10 +194,14 @@ namespace Alepha::Hydrogen  ::detail::  ProgramOptions_m
 			// Inspect and print each option.
 			for( const auto &[ name, def ]: programOptions() )
 			{
-				std::cout << StartWrap{ width, alignmentWidth };
+				// When turning off wrapping, here, we also emit a newline between entries.
+				AutoRAII wrapping
+				{
+					[&] { std::cout << StartWrap{ width, alignmentWidth }; },
+					[] { std::cout << EndWrap << std::endl; }
+				};
+
 				const auto &[ _, helpText, defaultBuilder, domains ]= def;
-				// How much unused of the max width there will be
-				const std::size_t padding= alignmentWidth - name.size() - 2;
 
 				VariableMap substitutions=
 				{
@@ -221,33 +217,36 @@ namespace Alepha::Hydrogen  ::detail::  ProgramOptions_m
 					substitutions[ "canonical-name"s ]= lambaste<=canonicalProgramName.value();
 				}
 
-				std::string substitutionTemplate= name + ": " + std::string( padding, ' ' )
+				AutoRAII substitution
-						+ helpText.str() + "\n";
+				{
+					[&]{ std::cout << StartSubstitutions{ '!', substitutions }; },
+					[] { std::cout << EndSubstitutions; }
+				};
+
+				// How much unused of the max width there will be
+				const std::size_t padding= alignmentWidth - name.size() - 2;
+
+				std::cout << name << ": " << std::string( padding, ' ' ) << helpText.str() << '\n';
 
 				// Append the incompatibility text, when we see mutually-exclusive options.
-				substitutionTemplate+= buildIncompatibleHelpText( name, domains, exclusivityMembers );
+				std::cout << buildIncompatibleHelpText( name, domains, exclusivityMembers );
-
-				std::cout << expandVariables( substitutionTemplate, substitutions, '!' );
-				std::cout << EndWrap;
-				std::cout << std::endl;
 			}
 
 
 			// Check for required options, and print a summary of those:
 			if( not requiredOptions().empty() ) for( const auto &[ _, group ]: requiredOptions() )
 			{
-				std::ostream &oss= std::cout;
+				std::cout << StartWrap{ width };
-				oss << StartWrap{ width };
+				std::cout << "At least one of the options in this group are required: ";
-				oss << "At least one of the options in this group are required: ";
 				bool first= true;
 				for( const auto &required: group )
 				{
-					if( not first ) oss << ", ";
+					if( not first ) std::cout << ", ";
 					first= false;
-					oss << '`' << required << '`';
+					std::cout << '`' << required << '`';
 				}
 
-				oss << std::endl;
+				std::cout << std::endl;
 			}
 		}
 	}
@@ -289,10 +288,20 @@ namespace Alepha::Hydrogen  ::detail::  ProgramOptions_m
 			};
 
 			if( canonicalName.has_value() ) substitutions[ "canonical-name"s ]= lambaste<=canonicalName.value();
-			std::cout << wordWrap( expandVariables( helpMessage, substitutions, '!' ), getConsoleWidth() )
-					<< std::endl << std::endl;
-		}
 
+			AutoRAII wrapping
+			{
+				[] { std::cout << StartWrap{ getConsoleWidth() }; },
+				[] { std::cout << EndWrap; }
+			};
+			AutoRAII substitution
+			{
+				[&]{ std::cout << StartSubstitutions{ '!', substitutions }; },
+				[] { std::cout << EndSubstitutions; }
+			};
+
+			std::cout << helpMessage << std::endl << std::endl;
+		}
 		printAllOptionsHelp( canonicalName );
 		::exit( EXIT_SUCCESS );
 	}

ProgramOptions.h

@@ -327,8 +327,6 @@ namespace Alepha::Hydrogen  ::detail::  ProgramOptions_m
 			}
 	};
 
-	void printString( const std::string &s, const std::size_t indent );
-
 	struct OptionString { std::string name; };
 
 	namespace exports::inline literals