Merge pull request #43 from pavel-belikov/better-help

Add more help parameters

2 files changed, 163 insertions, 21 deletions

diff --git a/args.hxx b/args.hxx
index c595ab7..7af24c4 100644
--- a/args.hxx
+++ b/args.hxx
@@ -114,37 +114,48 @@ namespace args
 
         std::istringstream stream(in);
         std::vector<std::string> output;
-        std::ostringstream line;
-        std::string::size_type linesize = 0;
+        std::string line;
+        bool empty = true;
+
+        for (char c : in)
+        {
+            if (!isspace(c))
+            {
+                break;
+            }
+            line += c;
+        }
+
         while (stream)
         {
             std::string item;
             stream >> item;
             auto itemsize = Glyphs(item);
-            if ((linesize + 1 + itemsize) > currentwidth)
+            if ((line.length() + 1 + itemsize) > currentwidth)
             {
-                if (linesize > 0)
+                if (!empty)
                 {
-                    output.push_back(line.str());
-                    line.str(std::string());
-                    linesize = 0;
+                    output.push_back(line);
+                    line.clear();
+                    empty = true;
                     currentwidth = width;
                 }
             }
             if (itemsize > 0)
             {
-                if (linesize)
+                if (!empty)
                 {
-                    ++linesize;
-                    line << " ";
+                    line += ' ';
                 }
-                line << item;
-                linesize += itemsize;
+
+                line += item;
+                empty = false;
             }
         }
-        if (linesize > 0)
+
+        if (!empty)
         {
-            output.push_back(line.str());
+            output.push_back(line);
         }
         return output;
     }
@@ -571,6 +582,26 @@ namespace args
         /** Use short flags in program lines when possible
          */
         bool proglinePreferShortFlags = false;
+
+        /** Program line prefix
+         */
+        std::string usageString;
+
+        /** String shown in help before flags descriptions
+         */
+        std::string optionsString = "OPTIONS:";
+
+        /** Display value name after all the long and short flags
+         */
+        bool useValueNameOnce = false;
+
+        /** Show value name
+         */
+        bool showValueName = true;
+
+        /** Add newline before flag description
+         */
+        bool addNewlineBeforeDescription = false;
     };
 
     /** Base class for all match types
@@ -832,23 +863,28 @@ namespace args
             virtual std::vector<std::tuple<std::string, std::string, unsigned>> GetDescription(const HelpParams &params, const unsigned indentLevel) const override
             {
                 std::tuple<std::string, std::string, unsigned> description;
-                const std::string postfix = NumberOfArguments() == 0 ? std::string() : Name();
+                const std::string postfix = !params.showValueName || NumberOfArguments() == 0 ? std::string() : Name();
                 std::string flags;
-                for (const auto &flag : matcher.GetFlagStrings())
+                const auto flagStrings = matcher.GetFlagStrings();
+                const bool useValueNameOnce = flagStrings.size() == 1 ? false : params.useValueNameOnce;
+                for (auto it = flagStrings.begin(); it != flagStrings.end(); ++it)
                 {
-                    if (!flags.empty())
+                    auto &flag = *it;
+                    if (it != flagStrings.begin())
                     {
                         flags += ", ";
                     }
 
                     flags += flag.isShort ? params.shortPrefix : params.longPrefix;
                     flags += flag.str();
-                    if (!postfix.empty())
+
+                    if (!postfix.empty() && (!useValueNameOnce || it + 1 == flagStrings.end()))
                     {
                         flags += flag.isShort ? params.shortSeparator : params.longSeparator;
                         flags += "[" + postfix + "]";
                     }
                 }
+
                 std::get<0>(description) = std::move(flags);
                 std::get<1>(description) = help;
                 std::get<2>(description) = indentLevel;
@@ -2236,7 +2272,7 @@ namespace args
                 const bool hasarguments = command.HasPositional();
 
                 std::ostringstream prognameline;
-                prognameline << Prog();
+                prognameline << helpParams.usageString << Prog();
 
                 for (const std::string &posname: command.GetProgramLine(helpParams))
                 {
@@ -2268,7 +2304,11 @@ namespace args
 
                 bool lastDescriptionIsNewline = false;
 
-                help_ << std::string(helpParams.progindent, ' ') << "OPTIONS:\n\n";
+                if (!helpParams.optionsString.empty())
+                {
+                    help_ << std::string(helpParams.progindent, ' ') << helpParams.optionsString << "\n\n";
+                }
+
                 for (const auto &desc: command.GetDescription(helpParams, 0))
                 {
                     lastDescriptionIsNewline = std::get<0>(desc).empty() && std::get<1>(desc).empty();
@@ -2289,7 +2329,7 @@ namespace args
 
                     auto infoit = std::begin(info);
                     // groupindent is on both sides of this inequality, and therefore can be removed
-                    if ((helpParams.flagindent + flagssize + helpParams.gutter) > helpParams.helpindent || infoit == std::end(info))
+                    if ((helpParams.flagindent + flagssize + helpParams.gutter) > helpParams.helpindent || infoit == std::end(info) || helpParams.addNewlineBeforeDescription)
                     {
                         help_ << '\n';
                     } else
diff --git a/test.cxx b/test.cxx
index 71f1fb7..1189f97 100644
--- a/test.cxx
+++ b/test.cxx
@@ -964,6 +964,108 @@ TEST_CASE("Matcher validation works as expected", "[args]")
     REQUIRE_THROWS_AS(args::ValueFlag<int>(parser, "", "", {}), args::UsageError);
 }
 
+TEST_CASE("HelpParams work as expected", "[args]")
+{
+    args::ArgumentParser p("parser");
+    args::ValueFlag<std::string> f(p, "name", "description", {'f', "foo"});
+    args::ValueFlag<std::string> g(p, "name", "description\n  d1\n  d2", {'g'});
+    p.Prog("prog");
+
+    REQUIRE(p.Help() == R"(  prog {OPTIONS}
+
+    parser
+
+  OPTIONS:
+
+      -f[name], --foo=[name]            description
+      -g[name]                          description
+                                          d1
+                                          d2
+
+)");
+
+    p.helpParams.usageString = "usage: ";
+    p.helpParams.optionsString = "Options";
+    p.helpParams.useValueNameOnce = true;
+    REQUIRE(p.Help() == R"(  usage: prog {OPTIONS}
+
+    parser
+
+  Options
+
+      -f, --foo=[name]                  description
+      -g[name]                          description
+                                          d1
+                                          d2
+
+)");
+
+    p.helpParams.showValueName = false;
+    p.helpParams.optionsString = {};
+    REQUIRE(p.Help() == R"(  usage: prog {OPTIONS}
+
+    parser
+
+      -f, --foo                         description
+      -g                                description
+                                          d1
+                                          d2
+
+)");
+
+    p.helpParams.helpindent = 12;
+    p.helpParams.optionsString = "Options";
+    REQUIRE(p.Help() == R"(  usage: prog {OPTIONS}
+
+    parser
+
+  Options
+
+      -f, --foo
+            description
+      -g    description
+              d1
+              d2
+
+)");
+
+    p.helpParams.addNewlineBeforeDescription = true;
+    REQUIRE(p.Help() == R"(  usage: prog {OPTIONS}
+
+    parser
+
+  Options
+
+      -f, --foo
+            description
+      -g
+            description
+              d1
+              d2
+
+)");
+
+    args::ValueFlag<std::string> e(p, "name", "some reaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaally loooooooooooooooooooooooooooong description", {'e'});
+    REQUIRE(p.Help() == R"(  usage: prog {OPTIONS}
+
+    parser
+
+  Options
+
+      -f, --foo
+            description
+      -g
+            description
+              d1
+              d2
+      -e
+            some reaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaally
+            loooooooooooooooooooooooooooong description
+
+)");
+
+}
+
 #undef ARGS_HXX
 #define ARGS_TESTNAMESPACE
 #define ARGS_NOEXCEPT